Lunar Surface Rendezvous and Light Scout Outpost Missions

Lunar Surface Rendezvous
One of the ideas I liked from the TeamVision paper (though I think it could and should be taken farther) was Lunar Surface Rendezvous. Now, this term has been used in several different ways, so I'll define it as a mission architecture where multiple mission elements are landed separately at the same location, instead of all at once. Lunar Surface Rendezvous (LSR) came up several times during the Apollo program, first as a direct competitor to LOR, EOR, and Direct Ascent, and later as a way of enhancing the existing Apollo architecture. One of the ways that Apollo was originally going to be extended (had funding not been cut due to how unaffordable the transportation was) was to use LSR to preland some extra cargo before a manned landing, thus giving the astronauts a lot more tools, a spare rover, additional life support spares and supplies, and other various odds and ends. This would've allowed a lot more to be done in a given mission.

TeamVision suggested a form of LSR using prelanded robotic lunar rovers that would work in conjunction with a 2-man landing team to more thoroughly investigate the area of interest. Basically, the robotic rovers would scout out the area in advance, help the astronauts find the areas of most interest, and generally greatly enhance the capabilities of just the astronauts alone. One of the guys who was involved with the Bay Area Moon Society (David Bushman I think?) had given us a presentation about some of the work he was doing with human/robotic exploration teams, and he made a pretty solid case that humans and robots can accomplish a lot more working together than just humans or just robots could.

ESAS plans to use LSR for its base-buildup and operations missions. Basically, once they're past the sortie phase of exploration (and with the cost of their architecture, that will probably be a very short phase indeed), and have found a base site, the base will be built up over multiple launches. Some landers will bring habitat equipment, others construction equipment, or ISRU stuff, or crews, or what have you. Even the most dyed-in-the-wool HLV fan has to admit that there's just no way you could launch a complete lunar outpost in one piece. But once you're down on the surface, deploying stuff, hooking things up, loading and unloading, fitting out hab modules, and all that other stuff becomes a lot easier. Especially if a lot of the work can be done inside. Being on a planetary surface, under the influence of some gravity makes a lot of those construction tasks a lot more similar to terrestrial operations than trying to do similar tasks in zero-g.

But taking the idea further has some merit too. Doug Stanley, in one of his replies on the Q&A thread previously mentioned, explained that the "4 people for 7 days" requirement came mostly from some NASA studies that had been done pre-ESAS on lunar surface operations. As I pointed out in my previous post on 2-man architectures, there's no reason that all 4 of those people (and all the facilities to support them for 7 days) have to be landed on the same lander.

Why doesn't NASA land enough stuff to support 4 people for 6 months on a single lander? Or 6 people for a year? Because it would require much too big of a lander, which would cost too much to develop, and way too much to operate. By making the lander smaller, and less capable, but using LSR, ESAS provides a much cheaper approach than trying to do a Battlestar Gallactica scale lunar lander. However, you could see where that logic goes...

And Doug Stanley more or less admitted it. He said that had the 4 people for 7 days edict not been "blessed" by Mike Griffin as one of the ground rules, that EELV based architectures would have traded a lot better compared to the chosen ESAS architecture. And he's right. All the numbers I've run show that you could probably do a reasonable 2-man lunar architecture using stock, or nearly stock EELVs (or EELV equivalents like Falcon IX if it becomes available).

Light Scout Outpost Missions
The numbers I found show that a lander capable of shuttling a two-person capsule from LUNO to the surface and back is also capable of landing (one-way) a fully loaded Sundancer module. By changing the loadout of the Sundancer a bit (and removing non-lunar useful stuff like ACS systems and propulsion systems, etc), and reorienting it towards a two-person setup, you could probably stock enough supplies and equipment to allow those two explorers to stay around for 14 days, or even possibly overnight if you have the right equipment. In other words, you could probably increase the amount of man-days on the lunar surface, while giving yourself more flexibility.

You could call these missions "Light Scout Outpost Missions" (LSO missions?), because they could still be temporary, would cost a lot less than a full-blown 4-man lander, but would still allow enough time to thoroughly explore the nearby environs without having to commit all the money and resources needed to setup a full-scale base. It would be possible to do a lot more of these, even during base build-up, which would allow for a much more thorough exploration of the moon.

Right now with the existing architecture, there'll likely only be enough money to try checking out 2-3 locales before you have to settle down into a large-scale base. But with LSO missions, you could probably afford not only to scout out more places before setting down too much infrastructure, but you could also afford to continue such LSO sorties during base buildup, and even better, each LSO mission provides some of the seed infrastructure for future bases if economically interesting resources are discovered (like say if Reiner Gamma turns out to have a nickel iron meteorite core left at the bottom of it, or if an area that had Lunar Transient Phenomena turns out to have subselenian gas pockets, or any of a number of other potentially itneresting features that we just don't know about yet).

And if a sortie site turns out to be very interesting, its easy to incrementally resupply and send crew rotations there to continue exploration. Or you could use the longer time on the surface to do early precursor work on debugging ISRU processes or testing out construction equipment or processes before you commit to larger scale equipment.


The more you look at it, the more you realize that Lunar Surface Rendezvous is not only the way you eventually have to go for serious lunar development and exploration, but that if taken to its logical conclusion, it ends up also being cheaper, more capable, and more flexible than the alternatives.

WBC as EDS Update

I also wanted to post a quick update about that WBC as EDS idea. Ross Tierney (the guy behind the DIRECT concept) ran some simulations for me. Apparently for the specific design of the EDS, the 6-engine WBC wouldn't quite work. Apparently the thrust on the RL-10s is too low to deal with the fact that the EDS has to put itself into orbit in the first place (since the Ares V doesn't have the oompf to do the job all by itself) before it could be used for lunar transfers.

You might be able to get the design to work by going to RL10-Cs or RL60s if either became available, but your system would no be the same as the commercial WBCs, and wouldn't have much of a propellant fraction advantage over the current EDS design. And you'd still be fielding new engines, and designing a whole new stage.

OTOH, if on-orbit propellant delivery became a reality, the standard WBC design would be substantially better than the EDS.

So basically, if you insist on having your lunar transfer stage pull double duty as a third stage to compensate for the fact that your booster can't actually get its payload into orbit with two stages (because one of the two is a crappy performance SRB that is only being kept around because nobody wants a bunch of unemployed rocket nerds roaming the streets of northern Utah), then the Wide Body Centaur isn't an option, and you better develop the Stick and that J-2X. If you actually want a real cislunar transportation system, you need to be able to transfer propellants on orbit, and at that point, the WBC is an excellent system to start with.

Generic Tankers

One of the things that I keep coming back to about EELV derived lunar missions, is that while there are a lot of interesting possibilities out there, and they are likely to be a lot cheaper than the ESAS architecture, they're still very expensive. Compared to the price points that you'd really need to get to in order to have real cislunar commerce, even EELVs are completely unrealistic. The fairly obvious conclusion I keep coming back to is that until you have lower cost launch to orbit (ie sub $1k/lb), lunar commerce is a real challenge--maybe not impossible, but a challenge. In other words, you really need low-cost space access (probably in the form of truly reusable space transports) before most lunar business plans can be closed.

One thing that Lockheed (or Boeing) could do to help catalyze things would be to make a line of relatively low-cost propellant tanker modules for on-orbit propellant delivery. These could be as simple as a propellant tank with a standardized docking interface (and with standardized fuel interconnects), or possibly could have a small guidance package on-board. Just enough so that between the package and the launch vehicle upper stage, the propellants can either be delivered to a location where a tug can bring them in to the propellant depot, or enough to allow the generic tank module to do the rendezvous and close approach itself. Put that technology on the shelf so that any launch company that can put stuff into orbit can buy a version of the tanker module and launch it on their vehicle. Spend the money and time with ITAR lawyers to make sure that you can get at least some of the friendly international space programs (like Arianespace, and the Japanese launch companies) on board with the project.

Just by demonstrating the concept, setting a reasonable standard, and selling generic tugs (with scalable tanks depending on the launch capacity of the vehicle in question), you remove most of the technical risk for those companies to do on-orbit propellant deliveries. While that doesn't remove all the hurdles between where we are right now, and largescale orbital and cislunar commerce, it provides a good start. Once that technology is on the shelf (or in development), it makes it easier for other people to innovate.

Maybe somebody will contract with Lockheed to have them deliver a "used" Centaur stage back to LEO after dropping off a commercial satellite. Have it refilled, and checked out at a Bigelow Sundancer station, and then turn it into a small orbital propellant depot. NASA claims they'd buy propellants on-orbit for topping off the EDS/LSAM, if it becomes commercially available. They really do need the capability, because without it, their odds of losing a mission from launch delays is pretty high, what with the LSAM and EDS only being designed for 15 day loiters before they start cutting into margins. With it, they can really boost their lunar surface capacity (possibly as much as double the cargo mission payload). And even at the crazy price that EELVs go for these days, it would be a lot cheaper to top off EDS than to launch two Ares V missions, with two EDS's, and two landers.

Some large NASA missions (like JIMO for instance) could really benefit from being able to have their Centaur upper stage topped-off in orbit. That would allow the thing to fly on an existing booster, without having to sacrifice any capabilities.

Another potential market for LEO propellants might be if some other country wanted to do lunar missions on the cheap. Not everyone has drunk the ESAS koolaid. Maybe the Europeans, or Russia, or China, or India could become interested in licensing or buying outright the tanker modules, and then doing their own manned lunar missions using a much more affordable archetecture. You could land two guys on the moon using only two refueled centaur stages. India for instance could probably do a manned lunar mission using their own launchers. Or if they're saavier than that, they'd build their own lander and capsule, and launch them, but then buy a used Centaur on orbit, and buy "commodity" on-orbit propellant to fuel that and their lander. If you aren't NASA, and you're merely trying for the most affordable way of doing a lunar mission, you'll buy your propellant from whoever wants to ship it.

Or maybe someone could buy a "used" Centaur, and use it as a semi-reusable tug for sending paying customers on around the Moon joyrides. Use it a few times, and then discard it and buy another "used" Centaur. Judging from the medium flight-rate ticket price of an Atlas V 401, I'd be surprised if a new Single Engine Centaur stage was worth more than $15M--If you bought it used on-orbit, it could probably be had for a song. A refueled Centaur stage (stock, not Wide Body) could send 30klb on an Apollo-8 style free-return trajectory with separation after the TLI burn, and the Centaur doing a second firing to return itself to LEO for reuse.

I could probably think of other ideas, but I think that Lockheed or Boeing could do fairly well for themselves by field-demonstrating orbital propellant transfer, and developing and selling/liscensing a generic propellant tanker module.

What do you guys think?

Thanks

I'd like to thank everyone who commented publically or by email to my "Readers Survey". The support means a lot. I guess sometimes it just really helps knowing that you're actually making a difference, even if only a modest one. So, in case I've left you on pins and needles, Selenian Boondocks will keep on going so long as I still have any time for that. With Tiff now into her last month of pregnancy, and work being its normal roller coaster, and a little boy turning two next month...

By the way, for anyone who's been following along, Tiff got the cerclage out yesterday, so it's a normal pregnancy from here! First time for everything I guess...

Oh, and on another note, the alternative thesis topic I want to propose is shaping up a lot better than I thought. I've found a relatively local company that does the process I was interested in, it turns out they've done some similar work for different customers in the past, and seemed quite willing to work with me on this (even as a poor starving college student).

But while I will likely be getting very busy, real soon now, I'm still going to try getting my next couple of topics out for discussion: lunar surface rendezvous, potential near-term lunar markets and what is needed to open them up, probably another essay about DIRECT, and some musings I've been having about the importance of backup plans.

Odd Bleg: RL10-C

Hey guys, I was trying to find if anyone had specific details about what ever happened to the RL10-C engine concept. Mark Wade lists it as having entered operational service, but the one stage they listed it as being used on (the Delta III Upper stage) actually used the extendable nozzle version that is also used on the Delta IV upper stages. I'm trying to figure out if the concept ever really did make it into hardware, and if so, what its status is.

The reason I'm curious is because if it was fully developed, and especially if it could be brought back into production, it might have a lot of use in the commercial manned orbital spaceflight world. Unlike other RL-10 engines which tended to emphasize Isp (which makes perfect sense since most of them were intended to be used on GTO stages), the RL10-C only had 450s of Isp, but was supposed to have a whopping 50% higher thrust than most other variants (over 35klbf instead of the ~22klbf that most of the other variants have). It isn't a perfect engine, it weighs almost as much as two of the RL10A-4-2's that Atlas V's currently use, and only puts out 3/4 the thrust of a two-engine combo. But since it does that in a single engine version, that would tend to make it more reliable (and a lot more compact). For an Atlas V 401 using the RL10-C, you might be able to close out the black zones without sacrificing any payload. Heck, it might make even Delta IVM man-rateable without having to sacrifice too much performance to close out its abort black zones.

It also might make a WBC based EDS stage more doable, as you could get a lot closer to the T/W ratio of the current EDS while still keeping a better mass ratio.

Anyway, the engine as I said isn't perfect, and things can still be done without it, but if it was either on-the-shelf, or close, it might be worth reinvestigating. Especially with the potential change in markets that could be coming from what Bigelow is doing with Lockheed.

Anyhow, if anybody with contacts inside of Pratt and Whittney could forward a link to this to your friends, I'm really curious. It might not be a good idea, but then again...

Now That Explains A Lot (ESAS Edition)

I've been rather enjoying some of the discussions going on at the NASASpaceflight.com forums lately. Unlike some of my usual haunts where I occasionally lurk (like sci.space.policy), most of the people there aren't people that I've been arguing with for just over a decade. It's always nice to see new (or old) perspectives that haven't yet been tainted by what sometimes passes for the alt.space conventional wisdom. I don't think that the alt.space conventional wisdom is necessarily wrong, I just think that it's sometimes refreshing to hang out in a place where people with a lot of experience disagree with you. It makes you think through and reconsider your stances on things, and even forces you occasionally to change your mind. It's kind of an interesting learning experience. A lot of what I learned about space I learned the hard way by shooting my mouth off in forums like that.

Anyhow, I was participating in a Q&A thread that had been arranged with Dr Doug Stanley of NASA regarding the recently completed Constellation Propellants Options Study. Dr Stanley is a close friend of Mike Griffin's and was one of the main people who Mike tasked with putting together the Exploration Systems Architecture Study. If anyone has some good insight into why decisions were made by the ESAS team, he'd be a good place to start. Anyhow, the thread had a lot of really good information, not only about propellants, but some things about lunar lander design concepts, and ISRU--I would recommend reading through it a bit if you have the time.

Then, in response to a question about forward applicability to Mars, Dr Stanley shared something that I find rather worrying. I was originally reticent to post this, because even though it was on a public forum, I'm not entirely sure that he wants his comments dragged out into the blogosphere, but I think what he said sheds a lot of light on the thinking behind NASA's current architecture. Here's the quote:

Now I am going to let you in on a little secret! Shhhh...don't tell anyone, OK? If I were in charge of National Space Policy, I would not even go to the Moon! I am actually a Mars First/Direct person. I would like to get to Mars as soon as possible and think that the Moon will be a distarction from that. If we establish an outpost on the Moon, NASA's entire exploration budget expected to be available will go to the operation of that outpost and the exploration of the Moon. I am afraid it will be the "tar baby" we will be stuck with that will keep us from going to Mars in my lifetime. NASA will need a significant budget increase to do both, which I don't think is likely. Mars is 10 times more interesting to me because of the atmosphere, the water, and the possibility of life below the surface...I would prefer to focus on a robust robotic exploration program including sample return, including human precursor mission, followed by human missions within the next 15 to 20 years.

I was asked by a friend to do ESAS and was working within the requirements I was given as a part of the VSE. I could not change them. But, If the next administration wishes to re-focus on Mars, all of the building blocks will be there. We will have preserved the Shuttle components and momentum to build a Heavy-lift launch vehicle and have a CLV and CEV that can launch humans to a MTV and a CEV that can even serve as an Earth-entry vehicle with more TPS...We will not have yet spent any appreciable funds towards lunar transportation or surface systems...I made sure we reserved this flexibility...

Shhh...don't tell anyone...

To be fair to Dr Stanley, everyone has their own preferences and opinions, and we're all entitled to them. I have no more right to tell Dr Stanley to stop being a Mars nut than he has to tell me to stop being interested in Lunar development.

That said, I find it rather disheartening to hear that the guy who led the team that came up with the study that NASA is now going to blow something like $50-60B over the next decade or so implementing doesn't think it's affordable to do what the President wanted. Even more disheartening is the openly expressed desire for the whole Moon thing to go away so we can focus on Mars.

It does really explain a lot though, doesn't it? I've found that a lot of the people that I talk with about who are firm believers in HLVs, when I've taken the wind out of their sails regarding the supposed need for HLVs to explore the Moon invariably fall back to Mars as a crutch. The argument goes that we absolutely must have HLVs to explore Mars, so we ought to develop them now. Because it's "moon, MARS, and beyond", don't ya know. Thus saith the Zubrin.

I just really wonder. If Dr Stanley, and others like him, really want to go to Mars so bad, why are they intentionally endorsing an architecture that they admit is too expensive for the job? Say you absolutely feel at the bottom of your soul that while the Moon is interesting, that Mars is where we need to be gearing up for. Why the Shaft? Why the EDS? I can kind of understand the HLV--I think the fundamental logic is completely broken, but at least I can empathize with people who feel that way. But why support all these other things that in the end are what makes ESAS so unaffordable that it can barely sustain a tiny 4-man shack on the moon, and that's with spending almost all of NASA's multi-billion dollar yearly ESMD budget to accomplish even that?

If you really feel that HLVs are a must, and feel that we have to keep Shuttle Derived Vehicles around to keep the Congresscritters happy, then why support the other programs that amount to little more than redundant wastes of NASA's finite resources. I've outlined several different alternatives here on this site for how to launch people into space on commercial boosters. That technology is not something NASA alone can do, and in fact is something they are required by law to do if the capability exists.

The EDS is little more than an over-glorified Upper Stage. Boeing, Lockheed, and others have been building those for coming on 40-50 years now. The 6-engine version of the ICES upper stage that I recently highlighted will be 50% bigger than ESAS, have a better mass fraction, will probably cost less, and will have the benefit of being flight proven by the time NASA needs to use it. Since Lockheed wants to go with ICES stages for all of their future Atlas V launches, that means that the "EDS" will still be available even if NASA doesn't buy any on a given year. That's one of the big benefits of using commercial hardware. If Saturn V had been cost effective enough that there was commercial demand for it (it wasn't--sorry Sam), it would still be around today. The whole reason Congress was able to force NASA to close the line down was because NASA was the sole customer for it.

The Shaft is also a redundant waste of money. Lockheed is in the process of man-rating their Atlas V for space tourism applications. SpaceX and RpK are also working on the problem. SpaceX is designing its vehicle from the ground up to be man-rated. Even Boeing I think will get its head on straight in the near future. Why do we need another man-rated launch vehicle? Without the development and fixed operational costs (not to mention marginal launch costs) of the CLV, being able to do Moon, Mars, and Beyond instead of just picking one becomes a lot more feasible. If you really care about Mars exploration, don't you think that freeing up several billion dollars for Mars exploration by finding a way to slim down the CEV so it can launch on existing launchers is a better way to go? Even if it has to be dry-launched (or semi-dry-launched)?

Look at it. Between CLV and EDS, you're talking almost $2B per year in fixed costs. Even if you don't fly a single mission. When you add in the costs of using CLV and current EDS for lunar sortie and base missions, you're talking somewhere between 1/3 and 1/2 of NASA's Exploration budget.

I just wonder why when the ESAS team was tasked with finding a way to sustainably explore the Moon, Mars, and Beyond, they picked an architecture that even their leader knew would be too expensive to do more than one of the three?

[Bleg: Maybe I've got a chip on my shoulder about these things, and most of you agree with Doug or couldn't care less. But, if any of you guys feel the same way I do, and especially if you feel as strongly about it as I do, PLEASE post your comments here on the SelenianBoondocks, instead of cluttering up Doug's Q&A thread on NASASpaceFlight.com. I don't want him getting flooded with email and commentary from everyone. The best way to piss people off, burn bridges, and get peoples' hackles up is to flood them with criticisms.

I sent him a link to my blog post, and if he wants to hear our opinions, he can read the comments here like everyone else. I figure that since he probably didn't intend this to be the talk of the alt.space blogosphere, that would be the most courteous way of handling things. If you have questions for him relevant to the topic of that forum though, feel free to ask away, I'm sure he'd appreciate that. ~Jon]

The Myth of the Low Cost HLV

I commented on this over at hobbyspace, but felt this deserved its own quick little blog post.

Every now and again, people will trot out a tired argument that HLVs are proven to be much cheaper per pound than smaller vehicles. Or that expendable HLVs are much cheaper than reusable ones like Shuttle. The people then trot out the marginal cost of the Saturn V: ~$431M, and say "look, it only cost about $1700/lb, that's cheaper than anything we have today", and usually go on to conclusions about how "if we hadn't retired the Saturn V, we would have been able to accomplish so much more".

There's a couple simple problems with this analysis:

1. You can't compare costs in 1967 dollars to 2006 dollars without factoring in inflation. If you use the inflation calculator, that $431M in 1967 is supposedly equivalent to nearly $2.5B in 2006 dollars. That's nearly $9k/lb, which is three times worse than existing EELVs. Even if you disagree with the methodology of that inflation calculator, some inflation has occured. Here's a link to a NASA site with several different inflation calculators. Only the most optimistic two would place the marginal cost of a Saturn V at less than $2B each, and the worst was nearly $3B each.


2. You can't compare just the marginal cost of a government program to a commercial program that also has to cover its fixed costs. A fair "apples-to-apples" comparison involves factoring in both fixed and marginal costs. When you choose to keep a vehicle around or to use a vehicle, you have to pay for those fixed costs. They don't come for free, so just handwaiving them away doesn't work. According to the Wikepedia site, about $6.5B was budgetted for Saturn V over the period of 1964-1973, with the peak being $1.2B in 1966. Adjusting for inflation (and assuming naively that you can just divide the total program cost by the number of years to get an average since more detailed info isn't easily available), you get the equivalence of somewhere between $3B-4.5B per year. The maximum flight rate for Saturn Vs was 4 per year. However, you spend that amount whether you launch one or four missions. Sure, you could probably cut back a bit if you were going into a one-flight per year mode, but the end result is you're talking at best $3.5B per flight of Saturn V (assuming 4 flights a year), and at worst something in the $4.5B per flight for a one-flight per year tempo (assuming you could halve fixed costs and still keep a flight per year in the system) That comes out to nearly $17k/lb to orbit, which is actually more expensive per pound than Shuttle at 4-5 flights per year!


3. Even keeping one-two Saturn V flights per year going would have cost $4.5-7B (in 2006 dollars), which would've been something like 50-70% of NASA's total budget.

Just food for thought next time anyone pines about the loss of the Saturn V. With the amount the NASA budget was slashed by Nixon, had they kept Saturn V, they could've afforded almost nothing else. There would've been no money for big space stations, there would've been no money for a continuing moon program, there would've been no money for Voyager and all the rest.

And the sad thing is that we're making the same mistakes again. We're tying ourselves down to expensive vehicles that cost billions of dollars not-to-fly, and billions more to fly occasionally. Dumb idea. I wish NASA's inability to learn from the past wasn't dooming us to have to repeat it with them. Here's to hoping that this time around we have a solid alternative. Then NASA may end up facing what we have to out here in the real world. You either learn and adapt, or you die.

Anyhow, that's enough for now. It's off to work now.

[Update: I was looking through the numbers I referenced, and some of them may be at least slightly incorrect. Apparently the $431M per launch number actually came by dividing the other number (the $6.5B) by the total number of Saturn V's flown. So that may have included development costs and fixed costs as well as marginal costs. However, there are a bunch of other funding categories listed that might also be "fixed cost" related that weren't included in the $6.5B number. If the total cost per flight was really "just" $431M in 1967 dollars, then the numbers aren't quite so bad. It's only 70% as expensive as the shuttle...which is to say still more expensive than most other launch vehicles. But it's hard to tell 100% what the fixed costs were, and therefore how much it would have cost to keep Saturn Vs flying had it not been for Nixon "being so shortsighted". Does anyone have any better data they can bring to the table? Stuff that more clearly separates out what percentage of the other categories are actually Saturn V operations related?]

Reader Survey?

Just out of curiousity, how many of you guys actually find what I have to write useful? I'm curious, because I sometimes get a decent amount of traffic on some of my articles, and I'm sure that most people reading it probably don't have a lot of comments. But sometimes I just can't help but wonder if I'm wasting my time on some of these topics. Having a day-job with an alt.space company means that I tend to have way too much on my plate to really delve into issues in the detail that some critics would like to see, while at the other time some of the topics that I know the most about, I can't really talk about (for ITAR or proprietary reasons). So I've been trying to toss out some thoughts, get the ball rolling and such...but it really doesn't seem to be rolling anywhere?

I've always doubted that I'd be able to have much of an impact on massive public decisions like the ones being made at NASA over mission architecture and such, but I'm not even sure if any of my thoughts or ideas are even really making any sort of lasting impact on even the private side of things. I think ideas like dry-launch, propellant transfer, manned commercial projects, etc have a real role to play in the development of space. I just don't see anything actually happening on most of those fronts. Am I just being too impatient? naive? sleep deprived?

Anyhow, what do you guys say? Are any of these topics useful? Do you think its making any sort of a difference to anyone outside of the allready convinced? You don't have to comment directly in the comments if you'd prefer anonymity, just drop me a line at jongoff gmail com. I'm just really trying to figure out if this is worth the amount of continual effort and time I'm sinking into it, or if I should reprioritize things a bit.

Dry-Launch vs ESAS Loss of Mission Numbers

A couple weeks back, I brought up some fundamental flaws I saw in the logic that the Exploration Systems Architecture Study group used to come up with their preferred lunar transportation architecture. In a discussion on NASASpaceFlight.com, I started realizing that even using their own methodology, a dry-launch propellant-transfer architecture might actually have a lower "Loss of Mission" probability than the preferred ESAS Architecture, in spite of requiring many more launches. And that is even ignoring almost all of the flaws I pointed out previously.

In the ESAS paper, they detailed three main sources of potential Loss of Mission:

1. Rendezvous and Docking Failures


2. Launch Vehicle Failures


3. Launch Vehicle Availability Issues

On the surface, it would seem that an EELV based mission, that might require 6-12 flights per mission would obviously lose in this analysis. After all, more flights means more chances to lose a payload, more payloads that might fail to dock correctly, and more payloads whose schedules slip, right? Not necessarily.

One of the key things to remember about the ESAS architecture is that most of the Initial Mass in LEO (IMLEO) is propellants. A frequent commenter on this site said something elsewhere to the effect that "Most of what Ares V does is launch LOX". Without the propellants, you could pretty much launch all of the ESAS hardware on two EELVs, one standard size, and one heavy, especially if the Heavy were an Atlas-V using the Phase I Wide Body Centaur upper stage mentioned in my last post. All of the rest of the flights are delivering propellants.

Upon a little thought, you realize that the only failures that can cause a loss of mission are failures on hardware flights. A lost propellant flight doesn't cost you the mission, since you can easily fly a replacement. Only a failure involving the docking or launch of one of the hardware flights actually eliminates something unique that you needed for the mission.

So, comparing the ESAS architecture to a dry-launch architecture, we find that:

1. Both architectures only have one mission-critical docking event that of the CEV to the LSAM/EDS stack. All other launches in the dry-launch architecture are not unique, and will not result in a loss of mission if the rendezvous and docking fail. At most they will result in a delay. So, the LOM numbers for rendezvous and docking failures are identical between the two architectures.


2. Both architectures only have two mission-critical launches, the hardware launch (LSAM and EDS), and the crew launch. If a crew is lost or if the cargo gets put into a "fishing orbit" as I like to call it, the mission is over. ESAS claims that their all-new launchers will be safer and more reliable than EELVs, but only slightly so. And theoretical hardware-reliability numbers rarely reflect the true reliability of the systems. Witness Shuttle and Falcon I. But you could call this as slightly in favor of the current ESAS architecture. Their odds of losing a mission-critical launch are probably about 1% lower than for Dry-Launch.


3. Where the current ESAS architecture loses the worst is ironically where they claimed a multi-launch architecture suffers the most--launcher availability. Basically, the current ESAS architecture has no way of topping-off the EDS/LSAM propellants before departure, so any delays above a certain amount end up costing the mission. Without a way of transfering propellant on-orbit, all of that expensive hardware ends up becoming next to useless if the CLV is late, or if the CLV suffers a non-fatal launch failure. The dry-launch architecture however can make up for delays. Any boiloff issues don't cost the mission, they just delay it slightly and add a tiny amount to its marginal cost. The odds of losing a mission due to CLV delays and boiloff with the current architecture are non-zero, but the odds of losing a drylaunch architecture to that are much, much lower.

To be fair, one can definitely quibble about whether the slightly higher theoretical launcher reliability is more or less of a factor than the inability to tolerate launch delays. However, what one cannot quibble about is that we're paying a very, very high cost for what is at best a very small, and entirely theoretical advantage.

An interesting sidenote from this though is that even if you insist on building Ares I and Ares V, developing on-orbit cryogenic propellant transfer still makes sense, as it can decrease your odds of launcher availability problems causing a loss of mission.

One can also claim that on-orbit cryogenic propellant transfer is so far off in the future that comparing it with the ESAS architecture is fantasy. However, Lockheed has a very valid point when they state that every time they relight a Centaur in orbit, they're demonstrating on-orbit cryogenic propellant transfer. They've only done it 200 times more than Ares I or Ares V has ever flown. While there is some development and qualification yet to be done on the concept, it's probably closer on both a monetary, and technical standpoint to reality than the J-2X or the 5-Segment SRB.

But the main takeaway I have for this is that the arguments for Ares I/Ares V are a whole lot less solid than ESAS tries to prove.

Centaur Based Earth Departure Stage

A couple of days back, when I was doing some of my preliminary thinking about the TeamVision architecture, I did some back-of-the-envelope calculations trying to see what kind of lunar transportation architecture could be done with off-the-shelf (or nearly off-the-shelf) hardware. One of the single biggest problems with the current NASA architecture is that almost everything is being done with custom developed, NASA-specific hardware. Almost all of the money budgetted for Exploration over the next decade is going to developing launchers and transfer stages, and in retaining the standing armies for those systems. Between development, workforce retention, infrastructure upgrades, and all other related expenses, you're probably talking over $50B out of the $67B that NASA will spend on exploration over the next dozen years. Only a tiny pittance will actually be spent on lunar-specific hardware like the LSAM, the unmanned exploration hardware, and developing stuff to actually do once we get to the moon. Every year that the architecture is delayed will end up eating up over half of the budget just keeping all the people on the payroll!

An architecture that relied a lot more heavily on existing launch vehicles and upper stages would allow for much more actual exploration to be done.

Digression: Lunar Surface Rendezvous
So, I started poking around, looking at various combinations of stock, or nearly stock boosters and other hardware. The first conclusion I came to was that if you went to a two-man architecture and relied heavily on Lunar Surface Rendezvous type options you could greatly reduce the required IMLEO of the mission, and thus greatly reduce the number of launches needed to support it. I've already gone into LSR a little bit, and will definitely go into it in more detail in the future, but here's the basic gist of Lunar Surface Rendezvous architectures. Basically, if you have to launch everything for a given lunar mission on a single lunar transfer stack, you will run into limits very quickly on how much you can deliver to the lunar surface.

One of the lessons not learned from the Shuttle was that if you try to make your "space truck" into a space Winnebago, complete with housing facilities for a bunch of people for several weeks, and insist on being able to carry a lot of cargo to boot, you end up with a rather bloated system. LSAM is headed back down the same road. In the end you end up getting the worst of both worlds--an overly expensive, overly bloated transportation system, and extremely cramped and inefficient living conditions. NASA goes on and on about how "roomy" the CEV and LSAM are, but the reality is that for all the weight being thrown into them, they don't even have 1/4 of the space of a single Bigelow Sundancer module, in spite of probably expending more of their mass budget towards being roomy than the weight of such a module. It would be much better and cheaper, if you want to explore a site for a while, to preland a Sundancer (or Sundancer derivative) module, then send the crew. Unlike the LSAM which supposedly doesn't even have an airlock, and can only support a crew of 4 for about 7 days (28 man-days in other words), a Sundancer and a bare-bones 4-person lander could support the same crew for probably closer to several months. And you don't have to carry anywhere near as big of a lander, which allow for a much smaller IMLEO, and a much simpler architecture.

Even NASA intends to eventually do Lunar Surface Rendezvous, but only after they've designed their bloatware LSAM lunar winnebago. In other words, like with the shuttle, they're bound and determined to always find a way to get the worst of both worlds. If they went with LSR from the start, and actually took advantage of the options that opens up, they could make their lives a lot easier.

Off-The-Shelf
Anyhow, getting back towards my original point, I started looking around at what existing or near-term upper stages might be available for a lunar project. The two main ones I was considering early on were Centaur V-1 and the Delta IVH upper stage. The Delta-IVH upper stage uses the heavier, higher Isp version of the RL-10 engine, and has a lower mass ratio due to not using a common bulkhead, and a few other things. But its mass ratio was still pretty good, and more importantly, it had more propellant. So I spent some time looking at it, and it really looks like you could do a lunar mission using two D-IVH launches, or a D-IVH launch and two Atlas V 401 launches. It wasn't perfect, and didn't include a lot of the features you'd really like in such a system, but it was off-the-shelf, and not crazy. However, the margins were a lot lower than I wanted, even with a rather minimalist two-person architecture, so I kind of back-burnered the idea for the time being.

Wide Body Centaur
Then I re-stumbled upon some work that Lockheed Martin is doing as an upgrade to their existing Atlas V fleet--the Wide Body Centaur (aka ICES, the Integrated Cryogenic Evolved Stage). You can find some details on the Atlas-Yesterday, Today, and Tomorrow page Lockheed put up a few months back. Apparently, the Centaur V-1 and V-2 flying with Atlas V today are very, very similar to the same ones that first flew. They've upgraded the avionics over the years, gone to better manufacturing processes as they came out, upgraded the RL-10s over time, but never really changed the size of the basic Centaur stage very much over the past 30+ years. However, newer manufacturing techniques like Friction Stir Welding of thin aluminum tanks have come out, as well as the need for longer duration missions, so a couple years back Lockheed started designing the next iterative improvement on their venerable design.

The three biggest changes are the size, the structural layout, and the tank material. Unlike previous Centaurs which IIRC were all in the 3-4m range, the newer WBC will use 5m diameter tanks. Since area of a circle goes with the square of the linear dimension, that means an equal length WBC Centaur stage will hold over 1.5 times as much propellants. Additionally, they are going to invert the direction of the common bulkhead. This requires the LH2 tank to be run at slightly higher pressures, but will greatly reduce the heat transfer into the LH2 on-orbit, as well as simplifying the sump. The third big change is going from the previously used ulta-thin wall stainless construction to a friction stir welded thin-wall aluminum construction. They've done a lot of manufacturing development work over the past two or three years (some on their own dime, and some in conjunction with NASA), and now feel confident in welding aluminum tank sections as thin as .04in or thinner. The upshot of this last point is that they can improve their already impressive 91% propellant fraction to nearly 95% in some configurations (probably depends on number of engines, and the duration of the mission--longer duration missions require some additional goodies like MLI and solar panels). The other upshot is that this makes it very easy for them to make different sized tanks. All you do is friction stir weld-in more or less barrel sections in the LOX and LH2 tanks.

These stages range in size from about 1.5x the size of the current Centaur, all the way up to 6x as big. They have a common thrust structure which can accomodate 1-6 RL-10s, depending on size and thrust requirements. They can be configured for short durations, or very long durations (greater than a year) depending on which options you add in (things like star-trackers, solar panels, etc). The best thing is that if they develop the WBC, it will be used on every single Atlas V flight after this point, which means they will get a lot of experience with the system soon. It also means that the development cost gets spread out over many more launches, and the incremental cost of a stage will also be tolerably low. There's also the benefit that the WBC does not require any new launch pad infrastructure.

One more thing that I've mentioned previously, is that Lockheed now has a lot of experience with "settled" propellant technologies. Basically, by using the vented-off hydrogen run through a nozzle, they're able to generate enough continuous acceleration to always keep the propellants settled at the bottom of their tanks. This takes most of the difficulties out of on-orbit propellant handling. Basically, "settled" propellant transfer ends up being very similar to terrestrial propellant transfer, instead of being the complicated mess that zero-g transfer tends to be. Lockheed still needs to actually finish reducing this concept to practice, but they have a very good point about how near-term feasible that is.

Anyhow, now that I've mentioned some of the benefits of the WBC design, I'll just touch on two potential applications.

Wide Body Centaur LTV
The first interesting application was the one I started discussing at the start of this article, using the WBC as a lunar transfer vehicle. The big problem I mentioned with the existing Delta-IVH upper stage, and the Centaur-V1/V2 was that they were just a little too-small for use with a manned lunar architecture. You could do a 2-man architecture, but it would require either really minimalist landers and spartan crew capsules, or using two stages to get from LEO to LUNO, or require using the crew capsule or lunar lander to perform one or more of the burns. Using a WBC as a lunar transfer vehicle however would be a lot easier, due to their much larger propellant capacity.

Depending on if they also ever get around to fielding the Atlas V Heavy, you might even be able to do a "1.5 Launch" architecture. An Atlas V Heavy would launch putting just the upper stage with a bunch of excess propellant into orbit. Then, an Atlas-V 401 would launch the crew capsule, the lunar lander, and its own upper stage into orbit. The upper stage would be kitted out with slightly oversized tanks (1.8-2.0x current Centaur-V sized tanks instead of just 1.5x), the long-duration avionics suite, and some propellant transfer hardware. The manned lunar stack would rendezvous with the tanker, fill up it's own WBC stage, and then do some final on-orbit checkout (waiting for the correct timing for a lunar departure). The lunar transfer WBC would perform both the Trans Lunar Injection burn as well as the Lunar Orbit Insertion burn placing the stack into Lunar orbit. The two-man lander and capsule would then descend to the surface leaving a partially fueled WBC in orbit for the duration of their mission. When they're done, the lander would drop the crew capsule off on orbit, and the WBC would bring the capsule back to LEO--using 100% propulsive braking.

So, at the end of the mission, you'd have a reusable lander in Lunar orbit waiting for refueling and reuse, and you'd also have a lunar WBC sitting in LEO waiting to be reused. Based on the test results P&W claim, you could probably get 20-25 flights out of a given WBC before the engines wear out.

The same hardware used in a one-way cargo mode could put a Bigelow Sundancer module on the surface using only two launches.

Heck, maybe you could even steal a play from CSI's "Soyuz Around the Moon" project, and buy a used WBC on-orbit. Most satellites end up weighing less than the maximum payload capacity of the launcher they fly on, so a lot of the times the launchers will launch ballast along with the satellite to keep the mass properties correct. What if the "ballast" for a launch were a lunar-mission kit for the WBC (and enough propellant to put it back into an LEO parking orbit if the satellite was being dropped off in GEO)?

The coolest thing about an architecture like this is how flexible it is. While you can start out with a 1.5 Launch 2-man architecture, you can eventually work your way up to much, much bigger missions, since the maximum size for the Wide Body Centaur contains about 290+ klb of propellants.

Wide Body Centaur as EDS
Which brings me to my second idea. The Wide Body Centaur would be an ideal "Earth Departure Stage". It has more than enough performance, it has a lot of "long duration" features, and most importantly would be commercial-off-the-shelf hardware. Why blow extra billions developing a NASA-specific EDS, when a stock WBC with a lunar mission kit (solar cells, star trackers, and extra MLI) could do the job? Even if NASA insists on building the Shaft and the Ares V, using a WBC for their Earth Departure Stage would have several benefits:

• Save $5B+ on development costs


• Cut a year or two off of the current manned lunar return schedule


• Use hardware that would have a flight heritage by the point lunar missions start


• Save several hundred million a year on fixed costs associated with a NASA-specific EDS


• Have a design that is capable of accomodating even bigger missions in the future (the largest of the WBC configurations is about 50% bigger than the EDS)


• Have an EDS that uses flight-proven off-the-shelf propulsion systems, in an engine-out capable design


• Have an EDS that has a much lower marginal cost since it will be using hardware in common with every single Atlas flight


• Have an EDS that can store propellants for very long durations without requiring a complicated and expensive Cryocooler


• Be able to field test EDS functionality even before Ares V is in operations

All in all, the WBC could meet or beat every spec that NASA needs out of the EDS. Congress should encourage Lockheed to develop this commercially, on their own dime. They could do this without spending any money, or commiting future congresses by stating in law that if Lockheed fields its WBC design (or if a competitor fields an equivalent or superior design) before a certain date, that NASA, will not be allowed to develop or operate its own EDS. Congress shouldn't have to do this. They've already passed authorization legislation that requires NASA to purchase commercial hardware instead of developing their own stuff whenever possible, but NASA always seems to find an excuse.

Conclusions
The Wide Body Centaur technologies that Lockheed has been developing over the past few years have a lot of potential. Even if NASA insists on doing Ares I and V their way, everyone would benefit from encouraging Lockheed to field the WBC sooner rather than later.

One of the single biggest benefits is that if the WBC gets fielded, then we have a backup option for lunar exploration even if Ares I and V run into issues. Backup options, especially off-the-shelf options that don't cost much if any NASA money to develop, would allow NASA to take the risks it needs to without having to worry that all will be lost if anything goes wrong with Plan A. Not to mention that by having a backup option, it will keep other contractors more competitive, because they know that their gravy train is not secure unless they really deliver a good, robust, and cost effective solution.

Comments?

Fun and Speculation With Lunar Magnetism

Our curmudgeonly friend over at Curmudgeon's Corner posted a link to an interesting article from Space.Com a few days ago. The article was talking about the small localized magnetic fields that exist on the moon. I had known for a while that while the Moon doesn't have a global magnetic field, that there were several local magnetic fields in certain areas of the moon, but hadn't really delved too far into the topic.

The interesting thing is that they seem to believe the fields come from magnetization of the kind of nano-phase iron deposits in the regolith that I had previously been mentioning, as opposed to being due to large potential nickel-iron meteor cores as I had thought. Dennis Wingo mentioned the possibility of Ni-Fe meteors surviving impacts with the moon largely intact due to the much lower median impact velocity on the moon (due to being higher up in the gravity well as I understand it). I wonder if any of the regions of high magnetic field line up with any of the charted "Mascons". That could make for a very interesting landing site, not just scientifically, but commercially as well.

The point they mentioned about the magnetic fields being strong enough to deflect all the solar wind based particles from the area is also interesting. As I understand it, during solar flares, the energy of the particles doesn't go up, it's the particle flux that goes through the roof. If an area was under enough of such a magnetic umbrella that normal solar wind particle didn't reach it, am I correct in assuming that it'd also be safe from solar flares? While that wouldn't get rid of concerns about Galactic Cosmic radiation (since those particles are much higher energy), not having to worry about solar flares is a good start.

Which gets me wondering even further. First off, if the Moon's weak primordial magnetic field was enough to magnetize these regions, would a much stronger magnetic field be able to magnetize them further? Or since nanophase iron particles are so prevelant in the lunar dust everywhere, could you recreate this phenomenon elsewhere? What if you found the core of a Fe-Ni meteorite. Could you induce enough of a magnetic field in it to help with the solar radiation problem? Even better, could you induce enough of a field to deal with GCR?

This is rather potentially interesting, as it would make setting up a mining camp for such a meteor impact site a lot easier. By inducing a strong local magnetic field, you'd no longer have to bury everything, and you wouldn't have to worry about solar flares either. Mining would get a little tougher (you'd have to make most of the equipment out of weakly non-ferromagnetic materials like some stainless steels, aluminum, etc), but by making it easier to live there, you definitely lower the hurdle for exploitation.

Here's another wild question. The NASA scientist who spoke about nanophase iron at the Return to the Moon conference a year and a half ago made it sound as though these nanophase iron deposites were assumed to be present in the regolith almost everywhere on the moon, and that the smaller the particle, the more the magnetically susceptible the stuff was. I wonder if this is true, is the magnetic field in some of those areas high enough to help keep the lunar dust down?


I really don't have a good feel for these numbers, and this is all just wild speculation, but does anyone here have better information? Paging Paul Spudis. Or Dennis Wingo?

Endurance

[Note: Before I delve into this topic, I feel I ought to mention that while I'm going to discuss project management/engineering issues, that I'm also going to be discussing other relgious/personal examples as well. Please bear with me.]

The debate over whether the Stick is having problems, and whether we should thus abandon it, or whether we must see it through has reminded me of an unsettled question in my life. Is it always right to keep going and see any difficult task through to completion, no matter the difficulty? Or is it best sometimes to reevaluate and change course when the going gets tough? How do you know which situation is which?

One of the things I got hammered into me growing up was the power of determination. If you set your mind to it, the saying goes, there is almost nothing you can't accomplish. Unfortunately, I've ran into several situations in the past which have made me wonder when it really is best to keep slogging through a tough problem, and when it truly is wisest not to keep slogging away at it, but to completely change courses.

Mission
The first time that I remember giving serious thought to the problem was on my mission in the Philippines. We often has people who would keep inviting us over, even though they really didn't seem to be interested in actually taking anything we had to say and actually doing anything about it. We'd keep going over every couple of days, and nothing would really change. They weren't antagonistic, but were basically of apathetic. All my training up until that point said, don't give up on these people. If they're even remotely interested, keep working with them, and eventually they'll come around. But at some point I started wondering if that was the most effective way of doing things. I only had a finite amount of time that I could use, and while those individuals were important, and I cared a lot about some of them, I wondered if it was right for me to keep investing what limited time we had on them when they really weren't ready yet, when I could instead be trying to find people who were. Trying to strike that balance was a real challenge. One that I'm not sure I ever really did well with. I may never know in this lifetime whether I squandered opportunities to share our message with people who truly were ready for it and could have been helped by it, or whether I was too hasty in dimissing someone as being "uninterested". Yes, I do lose sleep over this occasionally.

Thesis
Another experience that seems relevant is my thesis project. People ask me what degree I have, and I keep telling them that I'm "half a thesis away from" a Masters degree in Mechanical Engineering. Unfortunately, my department has a policy for Master's students that they have 5 years from when they start the program till when they have to graduate, or start all over. My time runs out in August, which means that I have to have my thesis done and defended by June, or I go back to being just a guy with a Bachelor's degree in Manufacturing Engineering, as though those two years of my life never happened. That would really suck. The problem is, I've gotten myself into a rather difficult situation with my thesis. To make a long story short, I chose a thesis topic, thinking that I would make a prototype of a new invention, get it to work, do some experimentation on various parameters to figure out what the best operating parameters were, and then analyze the data, write the paper, and be done with it. Unfortunately, the concept didn't work at all the first time. So, I researched it out for half a year, found some obscure references that were relevant, started making some math models, and started trying new design iterations. I changed the focus of my thesis to just trying to get enough data to be able to validate those models sufficiently that someone in the future could build a more optimized design. Unfortunately, in spite of having gone through something like 6-10 iterations now, I still haven't been able to get any clear evidence proving that anything I'm doing is having any effect at all. My models did very accurately predict the resonant frequency of the coupled piezoelectric-fluid dynamic system, but I've been unable to close the rest of the model, and I'm uncertain if my initial concept is even workable at all. I've thought of a couple of things I might be able to do to get better readings (going to a more viscous fluid to force the flow to be laminar so I can get a better comparison, going with a much lower frequency piezoelectric system to make sure I'm not getting any weird compressibility effects, going with a higher speed camera system to get better and clearer data, etc), but I have no idea if four months from now after I've done all these things if I will have even gathered enough data to be able to validate or invalidate my models, or even if I'll be able to complete the analytical modeling of the system. I'm pretty sure I can handle the piezoelectric/mechanical side of things, but the fluid dynamic coupling I'm not at all confident with. I could very well throw all of my free time between now and June at this project and still not have anything that I could defend.

So, I've been thinking about trying to change research topics to something closer to what I'm familiar with, and something more directly related to what I'm doing at work. One of the big issues with my old thesis was that I had almost $0 worth of funding (and had to beg my way into getting all the manufacturing I needed to do done for free). The other one was that it wasn't an area where I had a strong background in, and in fact the most complicated part of my thesis (the high-power piezoelectric part of it) was an area that none of my faculty advisors had a lot of relevant experience in. If I picked a topic that we were going to be working on at work anyhow, it'd be easier to find the time, I'd have more relevant background experience, and I'd be a lot more likely to get sufficient funding to carry out the project. We've got a few ideas that could make for great research projects, including ones having to do with new manufacturing methods for rocket engines, zero-g propellant settling, and a few others. There are some real risks in jumping topics though. The biggest one is that I have seven months to go from nothing to a defended thesis, and even in the best of situations, that'd be tough. More to the point, I don't know for sure if we're going to have the funding to pursue any of the specific research topics I've been thinking of. Most of them are of longer-term interest, and as is the case with most alt.space startups, we're not exactly swimming in so much cash that we can take on very many long-term uncertain-payout R&D projects. There are federal sources of funding like STTRs and SBIRs, but those take too long compared to my window of opportunity.

So, I really don't know which way to go on that one. If I stick with my thesis, there's a very real chance that I won't be able to get either the models or the experimentation far enough to finish and defend my research. If I jump topics, I'm taking a huge gamble on if I can finish, and if I can really get the resources I need to do the research. At times I wish life were as easy as the two-bit slogans people tend to toss around about willpower and determination.

Catalyst Igniters
Another example, that I think was a lot more clearcut was my experience with Catalytic GOX/GH2 igniters. Back before I joined MSS, I participated in a static firing of a large hybrid motor up at USU, as part of the Unity IV project. They had all sorts of igniter issues, and while they were finally able to test fire the engine by the end of the day, they had vented so much of their nitrous that they weren't able to do anywhere near the kind of testing they wanted to do. I had just read about some of John's work with catalysts, and how GH2 would catalytically burn at room-temperature with GOX. I thought that might make a great idea for an igniter, and decided to run with it. When we first started MSS, I was absolutely convinced that this was the way to go, and started trying to build such a system while I was still with the BYU Space Development Club out in Utah. We built the system, and started testing it, but kept running into various problems. I continued the research when I started at MSS. We kept running into issues with the catalysts either being not catalytic enough to get the stuff to light, or on the other hand being so fragile that they'd completely shatter with thermal shock. In the end, after doing a lot of research, I came upon some really good papers and handbooks done by NASA and some contractors back in the 60s and 70s, that gave me a lot of insights into what we were doing wrong. I then spent a bunch of time using the empirical models that I had found to develop my best stab at making a functioning catalyst igniter. At about that time, I started writing up some documentation of the project. As I've related previously, I started out with a simple psuedo-"trade study" to show why the catalyst igniter was really the best igniter option for our engines, and thus why we chose to investigate it.

Unfortunately, the numbers kept coming out in favor of either a spark torch igniter, or a resonance igniter, with the catalyst igniter always coming in third or fourth. I finally found some combination of weighting and tweaking of values to force the catalyst igniter to win, but by that point I realized that I was being a tool, and that it wasn't really such a great idea after all. Most importantly, I realized that even if the thing could be made to work perfectly, it wouldn't necessarily be that good of a system for use in our vehicle. I realized that I could keep trying to slog away at making such an igniter work, or I could focus on what it would take to actually achieve what we really cared about--a reliable igniter that we could use for test-firing and eventually flying engines. I killed the project at that point, and have never regretted it for a second.

When such a project ceases to support your main project goals, there isn't much point in trying to complete it. Even if you did, it wouldn't have been worth the wasted time.

Engine Testing and XA-0.1
On the other hand, here are two good examples of situations where slogging through has been the right decision. First off, we have our engine testing experience at MSS. When I started full-time at MSS back in October of '04, my two tasks were to complete the igniter development, and help Pierce put together a mobile rocket test stand. Up until that point, my actual useful hands-on experience with high-pressure plumbing, data acquisition, and electronics was almost entirely limited to the igniter project. The learning curve was very steep, and by the time we were winding that and our igniter development down, it was now getting into fire season at our remote test site location. So we ended up spending several months putting in infrastructure up there so we could test. Then when we got there, we ended up spending endless hours debugging our electronics and daq setup. We finally got into engine firings sometime about a year ago this month. And we had a steep learning curve with that hardware too. There were several times along the way when I never felt we were ever going to have a reliable, stable, steady-statable engine. I got really depressed at times standing on the hill in the cold, or sitting on the trailer gate waiting for Pierce and Ian to resolve some network or control or daq issue. But we kept at it, and eventually things started getting better. We started figuring out how to operate at a remote site more effectively. We became more thorough with our testing of controls and electronics there at the shop. We slowly worked through many of the hardware issues that were bugging us. In the end, we had a very high performance engine, that steady-states well, can fire down to very low throttles, and generally beat all of our expectations. Slogging through paid off.

XA-0.1 isn't flying yet, but now that we're finally getting through our dynamic throttling issues, patience and endurance are seeming like the right approach.

Concluding Thoughts
Life is always more complicated than theory. Sometimes slogging through a problem is the best approach, and sometimes it's best to give up and take another route. We do have finite time, money, energy, willpower, etc. As the famous demotivator poster says, sometimes your best just really isn't good enough. There are such things as impossible projects. There are projects that are possible, but not worth completing. There are other projects that appear impossible that are absolutely essential to stick through to the end. And the great challenge in life is to figure out what you should do from now.

I'm not sure I really have figured out how best to confront this dillema (or if in my long babbling here tonight if I've even shed any light on the concept). The best I've been able to figure is that you have to look at what really is important to you, and make sure that if you did somehow see it through, if the benefits would outweigh the costs. Does your course really lead to where you want to go, and is it the most effective path there? As CS Lewis put it:

If you're on the wrong road, progress means doing an about-turn and walking back to the right road; in that case, the man who turns back soonest is the most progressive.

What do you all think?

Ian Kluft X-Prize Cup Pictures

Ian Kluft just put up his photo report of the X-Prize Cup. He got some good pictures of the Armadillo crew, several of the ameteur rocket launches, as well as some pictures of our demo-firings with shock diamonds.

Ian has been a big supporter of ameteur rocketry events over the years, including his work with Stratofox, which helped with the tracking and recovery of the CSXT Go-Fast rocket that made it to space in late 2004. He's also been a great help to us at MSS over the past few years in many ways, including doing a lot of the photography for us over the years. Basically if the photo looks good, it was one of the two Ians (Ian Kluft or Ian Moore) who took it.

Check out the rest of Ian's page if you have the time.

Some More Jonny Bloggin

Somebody decided to give Daddy a hint that he needed to download some pictures off the digital camera, and do some more Jonny Bloggin:


So here's a few of the latest.


This one wasn't staged. Unlike my parents, I don't intentionally get Jonny all tired on Saturday nights and then give him a big oversized plate full of pasta and get out the camera to watch...


Oh, and somebody put it into Jonny's mind that Daddy's are meant to be their personal means of conveyance...

Maintenance of Lunar RLVs

Just wanted to post a few random, half-baked thoughts before I forget them about lunar RLVs. Back in the day, I had this thought-excercise going called the Prometheus Downport Project, which I recently dug up via the Wayback Machine on archive.org. The stuff is hopelessly obsolete by this point, but interesting nonetheless. Anyhow, back in 2003, in some of my copious free-time then, I got into some email conversations with a few friends about this, including Randall Clague (of XCOR fame). Randall got me thinking in some new directions (he was the one who mentioned the importance of the buddy system for lunar landings for instance), and raised some interesting questions. When I started gravitating toward the idea of a reusable lunar lander (one that goes from L1/LUNO to the surface and then back to L1/LUNO), Randall asked me how I intended on doing maintenance and repairs on the system. You could tell who had been working for a company that was actually flying rocket vehicles at that point.

Anyhow I was thinking about it again on the way home from work today. One thing that I have become a huge fan of for VTVL vehicles of any sort is the idea of system-level propulsion redundancy, with engine modules that are modular, and easily removeable (ie they are "Line Replaceable Units"), so that you can repair them offline. If one of them breaks down on the Moon, the repair method would be to swap out the damaged module and repair it somewhere out of the vacuum. If you're not in a place where you can easily do that (ie if you're at a remote exploration site, or on a first landing), you have enough extra engine capacity to make it "back to civilization" where you can swap out the engine for a spare while it's being replaced.

Which leads me to my one of my thoughts for maintenance/repairs of lunar RLVs. I have another one I will writeup at some point in the future, but here's one for now:

Sundancer On the Moon
Something like Bigelow's proposed "Sundancer" module would be the perfect starting place for any lunar outpost or spaceport. Back when I took a tour of Bigelow Aerospace during the Return to the Moon conference in 2005, I asked one of the engineers there if Bigelow intended to offer any smaller commercial modules than Nautilus, and mentioned that a smaller, lighter version of Nautilus might be useful. I doubt my suggest is why they did Sundancer, the idea makes too much sense for them to have not come up with it themselves, but I'm glad they did. 20klb is just about light enough that you could reasonably land such a beast on the moon. The 40-50klb Nautilus station would've been a little too heavy to land easily. As it is though, Sundancer is a wonderful size--170 m^3. Compared to the size of the proposed CEV and LSAM put together, the Sundancer module would be tons more roomy. There'd be enough room in a single such module for small sleeping quarters for 4-6, a bathroom, life support equipment, a kitchen/galley, a small lab, and most importantly a roomy workshop. If the airlock is big enough (or if the equipment is collapsible enough like the original moon buggies), you could bring a whole rover inside for repair and maintenance in a shirtsleeve environment. Bringing engines in and working on them indoors would be possible too. At that point you don't need exotic tools or anything--it's no more difficult than maintaining or repairing an engine on earth.

Your source of spare engines and parts might very well be the lander that brings the Sundancer module down. Early on you're not going to have a lot of spare propellants on the moon, and most propellants for a reusable lunar lander will be transferred from incoming tankers on orbit, so you might not be able to immediately reuse "one-way" cargo landers that are used to land extra-heavy cargoes like Sundancer modules. Even if you only cannabalize that first cargo lander, you'll have enough spare parts to keep a small fleet of 2-3 reusable landers maintained and in working order for quite some time.

One other related thought. When I was talking to the Bigelow engineer about how they intend on orbiting Nautilus (since it was spec'd out at 40-60klb fully loaded in LEO), he mentioned that if push came to shove, it could be shipped up "empty" and fitted out in orbit on subsequent flights. While I'm not sure exactly what that would mean in our situation, it might well make it so you could land a Sundancer module empty (on a smaller cargo lander), and land the rest of the stuff to fit out the Sundancer on a second shipment. That would probably drop the mass of the module to a low enough number that you could land it using two flights of the same lander design as would be used for a 2-person landing mission.

Oh, and in a low-G field (as opposed to microgravity), the life support equipment for the Nautilus can be made much more robust and reliable (and inexpensive too). No need to deal with phase separators, no issues with lack of natural convection causing concentrations of moisture or CO2, no need for a fancy zero-G toilet...

More Problems With The Shaft

Keith Cowing mentions in a recent post that:

Sources inside the development of the Ares 1 launch vehicle (aka Crew Launch Vehicle or "The Stick") have reported that the current design is underpowered to the tune of a metric ton or more. As currently designed, Ares 1 would not be able to put the present Orion spacecraft design (Crew Exploration Vehicle) into the orbit NASA desires.

Last week after my lament that I couldn't afford a subscription to the L2 section on NASASpaceFlight.com, a friend offered to buy me a subscription (thanks!), and I've been enjoying it ever since. The problems Keith was hearing about are the same ones that were being mentioned there, up to and including the supposed solution that NASA is now investigating:

One possible solution to the Stick's current design problems is to add side-mounted solid rocket motors.

If the guys on NASASpaceFlight.com are right, there are even more problems that are going to become public over the next couple of weeks (and so far they've been pretty darned accurate). The contortions that are being made to the system to keep the Stick as an integral part of the VSE are getting really out of control.
Fortunately as Keith mentions, at least several of the people involved are starting to see the light:

Many inside the program are not so sure that this solution is worth the effort.

While I am sure that the NASA, ATK, and Lockheed guys working on this are capable enough that they probably could get this thing flying at some point, the question is, will it have been worth it? Sometimes a strategic retreat is better than a Pyrrhic Victory. A Stick with strapons will actually be less safe by NASA's own standards, while costing more, taking longer to field, and being less capable than existing EELVs.

Unfortunately as Keith mentions:

It is widely known that both Mike Griffin and Scott Horowitz are reluctant (to say the least) about abandoning their current launch vehicle concept. Alternate approaches such as using EELVs are not welcome solutions by either Griffin or Horowitz.

Which raises an important question. If a project that is started in pursuit of a goal becomes detrimental to that goal, should one continue on to the bloody end? At what point do you decide that even if succesfully completed that project is no longer worth it? Will Griffin and Scotty do the honest and decent thing and put this lousy concept out of its misery? Or will they continue on down the course they're going until they've completely derailed the VSE? Now that Utah and Alabama's representatives and senators are in the minority party, will someone in Congress pull the plug on this travesty if Griffin doesn't?

At some point Griffin is going to have to chose between the Scotty Stick and the VSE. I have a hard time believing that he won't make the right decision in the end, but I sure hope he does it before any more unecessary money gets flushed down that rathole.

Lunar Crew Sizing: The More The Merrier?

As I mentioned in my previous post, after actually reading the TeamVision paper as opposed to merely skimming someone else's brief summary of their conclusion, I was a lot more impressed than I thought I would be. In spite of going off on what I think is a wrong direction later on in their paper, they had several insights in the first section of the paper that I found rather interesting (and not just because they presented some additional data to confirm my preconceived notions). The first one I want to briefly comment on revolves around the question of how big the crew compliment should be for a lunar surface mission.

The counterintuitive idea from TeamVision was that you could accomplish more exploration, for less money, sooner, and safer by using a two-man architecture instead of a four-man one.

This is an intriguing, and potentially controversial conclusion, and I'd like to give a few of my own thoughts. I'd also like to discuss a little bit about the implications of crew size on an architecture.

Why (Crew) Size Matters
The single biggest reason why crew size is important is how it impacts the overall transportation architecture. It's fairly intuitive that the more people you have, the bigger your lander needs to be, the more mass you need to start out with in LEO. The more "Initial Mass in Low Earth Orbit" (IMLEO for those of you out there that love you some acronyms) required, the more and/or bigger launchers you need.

For instance, a bare-bones minimal one person lunar mission such as the one George Herbert suggested for his Lunar Millenium Project back in the day could be launched on a single Delta IV Heavy, Atlas 552, or Proton. An upgraded two-person version of the Apollo LEM that used LOX/LH2 for all of it's interorbital transportation and LOX/Kero for the lander could be launched on two Delta IVH's, or a Delta IVH and two Atlas V 401s. However for a four-person long-duration architecture like ESAS, you start needing either on-orbit propellant transfer, a large number of EELVs and a lot of on-orbit assembly, or some sort of HLV, and even then you need at least some on-orbit propellant transfer or assembly.

The more assembly, on-orbit tanking, or HLVs you need, the higher a bar you set for initial missions. If you can use existing vehicles, and don't require a huge amount of up-front development, you can have boots on the ground doing exploration sooner.

Larger landing parties also make for less frequent sorties. HLVs have high fixed infrastructure costs and high marginal costs which tend to make it so you can only afford a couple of missions per year. On-orbit assembly or propellant aggregation from smaller launches also takes a set amount of time to get enough propellant for a mission. The larger the mission, the lower the flight rate. Higher flight rates typically end up making for lower-costs and higher reliability.

The Buddy System
The Moon as Robert Heinlein's book was titled really is a harsh mistress. While there have never been any fatalities during lunar exploration so far, space is a very dangerous place, and being the first guy to die on the Moon is a rather lousy way of getting yourself into the history books. There's a reason why out in the wilds the buddy system is often recommended. Many accidents or injuries that are quite survivable when you have a friend with you could end up being fatal if you are by yourself. You don't want to be like the guy in Utah a few years back who's arm got pinned under a boulder and then had to proceed to cut his own arm off with a pocketknife because he wasn't with someone who could help or get help.

Many potentially fatal accidents require nearly immediate attention to have even a decent chance of survival, especially anything related to decompression. Having someone else, nearby greatly increases your odds of surviving such an incident.

What does this mean? It means first that solo missions are probably right out. Sure they'd be a lot easier and cheaper, and lower cost to develop, but the risks of fatal injury are just way too high.

Second, it also means that odd-numbered crews are less effective than even-numbered ones. With three people, you really need all three to go out on an EVA. If you leave one behind, and go on an EVA with the other two, the third man would be taking big risks if he headed out by himself to meet up with or help that initial EVA team, which means he couldn't really do that much during an emergency. It also means that you'd probably need to size all rovers for three instead of two. While it is a marginal improvement over two, it probably isn't worth it most of the time. The same ends up happening with five or seven person crews. At least one of the teams will end up a threesome, and while that isn't the end of the world, and is probably at least a little better than a twosome, the productivity per person is probably a lot lower.

Teams with even numbers seem to the be the ideal size for optimal productivity. So the question boils down to which is better two or four?

Pros of a Two-Man Architecture

• Much higher transportation flexibility. A two-person architecture can be launched in a 2-3 launch mode using existing boosters (Atlas V or Delta IVH) with or without on-orbit assembly or propellant transfer. If a Shuttle Derived option is mandated by "political realities", you could launch the mission on a single smaller SDLV like the DIRECT concept.


• The lighter IMLEO requirements mean at most only one new booster is needed before lunar missions, which means that lunar missions can start at a much earlier date, and at a much lower cost, with more money available for actually developing hardware to use on the Moon.


• The lower fixed and marginal costs per person delivered to the moon makes it so you can actually do more exploration on a given budget.


• Higher flight rates mean more frequent resupply shipments which means lower probability that you'll have to abandon an outpost due to some important piece of machinery breaking down that you can't repair due to lack of spare parts. It's a lot easier to hang on for a month or two than it is for having to wait 3-6 months for a replacement part (as can be seen from recent ISS experiences).


• Vehicles like the planned LSAM that don't have an airlock require depressurizing the vehicle before any sortie. This means that if one team is going out, the other team has to don it's pressure suits as well. With a two-man mission, you don't have to worry about this. If one is going out, the other one pretty much has to anyway.


• Smaller, more frequent landings make it easier to explore more places on the lunar surface. This increases the odds that areas with useful resources can be explored much quicker than with a four-person two mission per year architecture.


• You can still do four-person missions, it just requires a second lander to land at the same site. That way if any of the four gets injured or sick, and needs evacuation to earth, only one person needs to go with him instead of having to prematurely end the rest of the mission.


• As ISRU technologies mature, a two-person lander can easily be upgraded to a four person lander.


• A two-man lunar capable CEV could be easily launched on existing boosters. Possibly even ones that are almost man-rated like the Atlas V 401. This means that you can start developing and testing the CEV itself a lot sooner, as you don't have to wait for the development, testing, and fielding of a completely new booster. This means a lunar capable CEV could be ready by 2010-2012 instead of having to wait until 2014-2016. This also means that an Apollo-8 style mission might be doable by about that time using a "1.5 launch architecture" with an Atlas V 401 and a Delta-IVH.


• Since a two-man architecture can be done with either LOR or EOR using existing boosters, if the NASA SDLV based design for some reason fails to get developed (due to budget cuts, technical failures, etc), there is a workable backup plan that still will allow for lunar exploration. Backup plans are a very good idea.

Pros of a Four-Person Architecture

• If one person is mildly injured, only one EVA team is taken out of commission instead of both.


• More ground at a given site can be covered more quickly without needing a follow-on mission.


• Four man landers allow for much larger unitary cargoes to be landed if the payloads can't be broken down into smaller chunks.


• There is a psychological benefit to claiming that you're doing more in a given mission, therefore aren't just "repeating Apollo" in spite of the fact that you really are.

I could keep going on this discussion, and there are a lot more details on pages 29-33 of the TeamVision report, and I've been writing this for too long already.

My personal opinion is that if you really want to get more exploration per given amount of NASA funding, and if you want to begin exploring as soon as possible, that changing the space exploration architecture to a two-man per lander design would be a very good idea. If it's cheaper, sooner, more productive per dollar, allows you to send more people to the Moon per year, allows you more flexibility, and allows you more programmatic redundancy, at what point do you have to admit that when it comes to crew size, bigger isn't necessarily better?

Light Blogging

I spent the evening tonight reading over most of the TeamVision lunar exploration architecture paper. It was an interesting read, and I'll try to comment on some of the ideas it gave me over the next couple of days. There's a lot of good thought in it, particularly for their nearer term stuff, though I think some of the longer term stuff was kinda out there.

Unfortunately I don't know how much time I'm going to have in the next few days to write up my thoughts. The paper was a whopping 61 pages, and there were several thoughts I got from it that probably should be developed separately instead of trying to kludge them all together into one writeup. I printed off a copy (double sided with 4 pages per side of paper...man that ends up being tiny writing), and took a bunch of notes in the margins.

Work's going to be a bit crazy over the next several days though. After solving the valve-twitch issues last week, we ran out of LOX on Monday before we could get to actual dynamic throttling. So, while we were waiting for another shipment of LOX to show up, we did a whole bunch of dryruns, and found and solved several more issues with our servo-control setup. The system as a whole is working a lot more robustly now, and we're feeling a lot more confident. We got in a bunch of LOX today, and tomorrow morning we will be out early making hot flamey stuff.

So, blogging should be rather light over the next several days...which if previous times I've said this mean anything, expect about 10 posts between now and Monday...

DIRECT and Other ESAS Alternatives

I've been following the discussions over on nasaspaceflight.com over the past few days regarding DIRECT and some other ESAS alternatives. One of these days I'd love to get access to their "Level 2" subscription service, but what with my $2k dental mistake, I doubt that's going to happen anytime soon.

Anyhow, there were five alternative technical approaches discussed, with varying levels of detail given. The current ESAS plan is bloated, high-cost, low-return, and already running into technical issues. The Shaft is still having some pretty serious performance shortfalls, with the estimated payload down to 21 metric tonnes down from a previous number of around 27. The vehicles are getting less and less Shuttle Derived as time goes on. 4-segment SRBs are morphing into new 5-segment SRBs (but still miraculously keeping all the paper-reliability of the ones that have actually flown). SSMEs are pretty much out. Ares V no longer really has any part of it that is really Shuttle Derived in any sense of the term (except maybe the paint scheme for its SRBs and LOX/LH2 tank). Budgets are slipping, as are the delivery dates. More and more infrastructure modifications are appearing necessary.

In other words those of us "armchair engineers" and "internet rocketeer" have slowly been proven right, over and over again. ESAS is supposedly infallible, yet time and time again, the technical issues we picked with it are turning out to be right. But don't you worry, those technical decisions are still being studied. The design isn't final yet. We have Top Men working on it. Top Men...

Anyhow, everyone with any sort of engineering clue can smell the blood in the water, so all sorts of pet architectures are coming out of the woodwork now. I've been purposefully avoiding trying to waste a bunch of time, brain power, and innocent electrons putting together my own detailed plan, precisely because it just isn't worth it. More to the point, any centrally planned lunar architecture is very likely going to be obsolete by the time it has a chance to get implemented. But that doesn't mean that there aren't useful things to learn from these other attempts. So here's a few short comments on each of the five ideas presented on NASASpaceFlight.

DIRECT
The guys who put together the DIRECT proposal, and the site www.directlauncher.com did a fairly thorough job of presenting their case. Here's how I see the pro's and con's:

Pro:

• By using only one vehicle instead of two, the yearly fixed cost for the launch vehicles is about half of that for both Ares I and Ares V. That's still $1B per year regardless of flight rate, but it's better than $2.2B per year fixed costs that ESAS entails. Lower fixed costs mean that there is more money every year available for either more missions, or to fund parallel projects such as propellant depots, COTS, or man-rating EELVs. It also means there's actual money available to buy on-orbit propellant if companies can figure out how to deliver it. The current ESAS plan really doesn't have the money available unless it closes down either Ares I or Ares V. And if you really think that we're going to abandon one of those vehicles after they actually exist, just because of commercial capabilities, you're fooling yourself. Look how hard NASA has been fighting to keep the Shuttle workforce around. Do you think those political "realities" are going to change even when the vehicles are provably obsolete?


• By only developing one vehicle, and by actually trying as hard as possible to reuse Shuttle hardware and infrastructure, the development costs for DIRECT would likely be as low or lower than even Ares I, but with the benefit of having all of your lunar launch vehicles developed and fielded by the early part of the next decade instead of the end.


• This plan is the most feasible from a political standpoint, since it keeps at least some of the pork gravy flowing into the right congressional troughs.


• DIRECT has the capability of bringing lunar missions at a much earlier date than 2018.


• Having regen cooled versions of the RS-68 would be cool. Bumping Isp up to 435s from 420s, and bumping thrust up by 5% would have a noticeable effect on the performance of the Delta-IV. Might even be enough to allow the single-stick Delta-IVM to be able to fly manned missions with a sufficiently depressed trajectory to not have any blackout zones, as the Lockheed guys are claiming they can do for an Atlas V 401. I've always felt that regen engines, while supposedly a bit more complicated to make are really the way to go if you're serious about rocketry.


• With the lower fixed cost of DIRECT, you could actually fly 2-3 lunar sorties per year before you've even spent as much as the fixed cost of just keeping the Ares I and Ares V lines open. In other words, you could at least double the mission tempo without increasing NASA's budget, or raiding other programs.


• By not needing as much money as soon, due to for instance not needing to rush a 5-segment SRB into existance, that puts less of a squeeze on the aeronautics and science sides of NASA. Now that we're looking at a Democratic congress, and possibly even a Democratic Senate (depending on how things settle out after a recount), that might be a more politically survivable approach.

Con:

• It's still a shuttle derived vehicle. While NASA's fixed costs for running earth-to-orbit transportation will drop considerably compared to Shuttle or the predicted numbers for ESAS, it's still $1B going every year to pay contractors to provide more redundant launch capacity.


• It still another example of NASA having its own booster instead of buying earth-to-orbit transportation. Contra-Mark Whittington, Ares I, Ares V, and DIRECT do not send crew and cargo to the moon. They send a little bit of crew and cargo to LEO along with a lot of propellants, and a little bit of transfer stage. Launching crew, cargo, and propellants to LEO is not something that only NASA can do, and in fact is something that NASA has demonstrated that it can't do in anything resembling a safe or cost-effective manner.


• It still only really helps encourage and enable commercial space capabilities if the supposed cost savings over ESAS are actually used for...encouraging and enabling commercial space capabilities. There's no guarantee that that money wouldn't just be funneled down some other congressional rat-hole.


• Like Ares V, it still doesn't have many good upgrade paths that could actually allow it to take advantage of advancements in commercial space capabilities as they occur. Even if commercial propellant depots on-orbit become a reality, DIRECT is still stuck with maintaining what would then be a completely redundant launch infrastructure (with about 80-90% of your IMLEO being propellant that can now be launched on smaller, cheaper, commercial vehicles, why do you still need an HLV?).

While DIRECT may possibly be the most rational and economically affordable and sustainable SDLV-based architecture I've seen to date...that ain't sayin' much. It probably has the most chance of happening, and would be a large improvement over the current ESAS debacle, but is still far from ideal.

MoonLight
I don't have quite as much time to go over the other concepts, but I want to give at least a few short thoughts. This Italian plan has some technical points that I strongly agree with, but also suffers from some serious issues:

Pro:

• I like reusable lunar landers.


• I like on-orbit propellant transfer and reusable lunar tugs. If NASA licenses the on-orbit propellant transfer technologies, that allows for commercial earth-to-orbit transportation companies to get involved, which would likely drop the transportation costs by a huge margin. The amount of propellant needed for even a meager NASA lunar program will likely rival near-term orbital tourism launch demand. And having that technology on-the-shelf for the private sector makes it easier for them to use it for their own commercial ventures.


• I like the idea of eventually having transportation and refueling nodes in either LUNO or L1/L2.


• I like the idea of not having to develop an HLV

Con:

• Not Invented Here Syndrome (heck this wasn't even invented in the US).


• Even though a new HLV isn't developed, I can't see NASA not horribly botching the design, development, and implementation of a fully-reusable tug, lander system, lunar space station, propellant depots, and everything else. The technological heart is in the right place, but run as a centrally-planned NASA run and operated project, it would likely end up as bad of a debacle as ISS and Shuttle have been.


• While the recurring costs of lunar sorties would likely go down, the fixed cost of a NASA run and operated lunar transportation system like this would be astronomical.

Lockheed's Plans
I think Lockheed's plans are the closest to my opinions, and I've talked about a lot of the elements on my blog previously, but here's a recap:

Pro:

• No need for launcher development. That alone saves $20-25B, which is likely enough to buy something like 360 Atlas V 401 launches, or a combination of Atlas V, Delta IV, Falcon IX, and Kistler K-1 flights. That also means that you can start development of your actual lunar hardware right now.


• The several billion per year freed up over the next several years could likely mean both having multiple independent commercial manned ISS service providers sooner than Ares I could be fielded, but it also means that most of the NASA lunar hardware could be ready to fly within the 2010-2014 timeframe, possibly allowing much sooner lunar sorties.


• NASA would have no money tied up every year in the fixed costs of operating its own earth-to-orbit transportation system. That comes to over $2.2B in savings per year that can go towards paying for more sorties, paying for a much more sophisticated exploration program, and possibly supporting multiple exploration bases.


• Lockheed's on-orbit propellant transfer concepts are based on existing flight hardware with decades of experience, and could probably be brought all the way to commercial viability very quickly, even if they have to develop it on their own dime.


• The EDS could likely be derived fairly strongly from Lockheed's venerable Centaur upper stages. This would likely drop development and operations costs.


• The lunar architecture would be launcher independent. This provides a lot of robustness to schedule slips, technical issues, and contractors trying to milk money out of NASA when they have them over a barrel. It also makes it so that the architecture can immediately benefit from lower-cost or safer launch vehicles as they come into existance. The large increase in global flight demand in a market that would mostly be open to only US launchers would draw a lot of commercial investment money back into the US launch market. The flight rates involved are even getting into the range that true orbital RLVs might actually get sufficient funding to have a chance.


• The current ESAS plan has now ability to re-top-off the tanks on the LSAM and the EDS once launched, which means that if the CLV is late, the mission will be scrubbed. The Lockheed plan however would be able to handle schedule slips like that rather trivially--just launch another tanker and fill 'er up.


• This plan helps move us toward becoming a truly spacefaring society. Not just a society with a government agency that every once in a while sends a few employees to visit space.


• Actual NASA employees could spend more of their time developing hardware for use on the moon, like reusable landers, base equipment, ISRU hardware etc. The current ESAS plan spends over 2/3 of its money on just developing and operating the earth-to-orbit part of the transportation system. Once you've also paid for the development of the LEO to LUNO transportation systems, and the landers, almost none of the money NASA plans to spend over the next decade is actually slated towards developing tools and technologies for use on the moon. Almost none of it is slated towards developing the components that would be needed for even a spartan base. At the rate we're looking at, such things couldn't even begin to be developed until after Ares I, Ares V, EDS, and LSAM were all fielded and operations--which means that actual base development wouldn't even start until post-2020.


• Most of the "Shuttle contractors" that ESAS is trying to keep together are Boeing and Lockheed employees (as well as employees of ATK and a couple other large contractor companies), not NASA employees. If NASA were buying dozens of commercial launches per year from Boeing and Lockheed, and if they and the COTS teams were providing the manned launches as well, many of those "shuttle employees" would actually be retained. Not the ones working in dead-end technologies like the technicians refurbishing large, segmented SRMs, or those doing tile repair, or overhauling SSMEs mind you. But the ones that have skills that are actually relevant to a truly robust space transportation architecture would be retained. Losing a skilled workforce in an obsolete technology is not always a bad thing. How many people lamented the skilled wagon makers that were put out of a job by Ford?

Cons:

• Unlikely to actually happen. Makes too much sense, and doesn't "keep the team together" as well as the Shuttle Derived options do. Doesn't allow NASA to play around with big rockets either.


• EELVs are still depressingly expensive and unreliable compared to where space transportation needs to get to. A lot of care would need to be taken to make sure that we wouldn't be replacing one launcher-specific architecture for another one.


• A commercial LEO launcher based architecture would benefit from more flexibility on NASA's part regarding minimum mission crew size. If NASA allowed for smaller crews, they could get far more missions, greater flexibility, and greater cost efficiencies of scale. Alas, NASA seems to feel that anything less than 4 people in a mission would somehow represent a step backwards. Even if it allowed them to fly more people to the moon per year, made the architecture more flexible, allowed for more diverse exploration, and generally made more sense.

There have to be some other Con's, but I can't think of many at this point.

CBO Alternatives
While I commend the CBO on noticing that the ESAS architecture isn't the most cost effective way of doing things, they still swallow whole some of the same false assumptions that ESAS did. While I'm sure an Atlas Derived launch architecture that used brand new UberAtlases could still be cheaper than Ares I and Ares V, I think that you lose almost all the benefit of going with a commercial vehicle once you start insisting on basically completely redesigning it again.

Pro:

• Marginally cheaper than Ares I and Ares V.

Con:

• You still end up with NASA paying large amounts of development costs for a new launcher, then having to pay all the fixed costs for the launcher as well as marginal costs. It has all the same problems as the current plan, just with slightly different packaging.

TeamVision
I'm not even sure where to start here. While it is an interesting technical approach, it seems utterly out of contact with reality. While ambitious, it also is I don't think very realistic. It has all the drawbacks of the MoonLight plan, while also having all the drawbacks of SDLV plans. High development costs, high fixed costs, unrealistic assumptions about how easy ISRU is going to be or how effective robotic precursors can be. I just really don't see anything in thise scheme even worth giving it more thought.

Anyhow, it's getting on towards 1am, and I have to be on the road to work in about 7 hours, so I think I'm going to call it a night. There's my take on things. In summary, I think that of these alternatives, that DIRECT is the most likely to get NASA to go along with it, but Lockheed's approach is the most in the right direction technically and economically. The other three while having some interesting ideas are all unrealistic or misguided in my opinion.