OSIRIS-REx
- 3. Table of contents • Introduction • Mission objectives • Why Bennu? • Previous research • Instrumentation • Conclusion
- 4. Table of contents • Introduction • Mission objectives • Why Bennu? • Previous research • Instrumentation • Conclusion
- 5. Introduction • “Origins Spectral Interpretation Resource Identification Security Regolith Explorer” Bennu OSIRIS-REx
- 6. Table of contents • Introduction • Mission objectives • Why Bennu? • Previous research • Instrumentation • Conclusion
- 7. Mission objectives Where did life and the oceans on earth originate from? • Return and analyze a sample of pristine carbonaceous asteroid regolith in an amount sufficient to study the nature, history, and distribution of its constituent minerals and organic material. • Map the global properties, chemistry, and mineralogy of a primitive carbonaceous asteroid to characterize its geologic and dynamic history and provide context for the returned samples. • Document the texture, morphology, geochemistry, and spectral properties of the regolith at the sampling site in situ at scales down to the submillimeter. • Measure the Yarkovsky effect on a potentially hazardous asteroid and constrain the asteroid properties that contribute to this effect. • Characterize the integrated global properties of a primitive carbonaceous asteroid to allow for direct comparison with ground- based telescopic data of the entire asteroid population.
- 8. Table of contents • Introduction • Mission objectives • Why Bennu? • Previous research • Instrumentation • Conclusion
- 9. Why Bennu? • “Near-Earth Asteroid” • Perihelion = 0.897AU, Aphelion = 1.356AU • Inclination = 6.035° • B-type asteroid; Organic compounds and water
- 10. Bennu 5 Carbonaceous 26 Large enough (>200m) 1,000 Optimal orbits >10,000 Near Earth Asteroids >600,000 Asteroids in the solar system Why Bennu?
- 11. Bennu 5 Carbonaceous 26 Large enough (>200m) 1,000 Optimal orbits >10,000 Near Earth Asteroids >600,000 Asteroids in the solar system Why Bennu?
- 12. Bennu 5 Carbonaceous 26 Large enough (>200m) ± 1,000 Optimal orbits >10,000 Near Earth Asteroids >600,000 Asteroids in the solar system Why Bennu?
- 13. Bennu 5 Carbonaceous 26 Large enough (>200m) ± 1,000 Optimal orbits >10,000 Near Earth Asteroids >600,000 Asteroids in the solar system Why Bennu?
- 14. Bennu 5 Carbonaceous 26 Large enough (>200m) ± 1,000 Optimal orbits >10,000 Near Earth Asteroids >600,000 Asteroids in the solar system Why Bennu?
- 15. Bennu 5 Carbonaceous 26 Large enough (>200m) ± 1,000 Optimal orbits >10,000 Near Earth Asteroids >600,000 Asteroids in the solar system Why Bennu?
- 16. Table of contents • Introduction • Mission objectives • Why Bennu? • Previous research • Instrumentation • Conclusion
- 17. Yarkovsky effect
- 18. Observations of Bennu • Hershel, Spitzer, VLT/VISIR • Thermal inertia: 310 J/m²/s^0.5/K o Tells a lot about particle size, rock abundance, bedrock outcropping • Albedo: 0.045 o Low value: primitive composition, organic compounds
- 19. Similar missions • Galileo and NEAR Shoemaker o help understand characteristics of asteroids in general, their relationship to meteorites and comets, and conditions in the early solar system • Hayabusa: Sample and return of 25143 Itokawa o Returned <4,000 dust samples in 2013 o S-type asteroid; iron- and magnesium-silicates o Thermal inertia ↔ regolith o Minerealogy and chemistry identical to LL chondrite meteorites • Several insights used on OSIRIS-REx
- 20. Table of contents • Introduction • Mission objectives • Why Bennu? • Previous research • Instrumentation • Conclusion
- 21. OSIRIS-REx Laser Altimeter (OLA) • LIDAR • 3D map of shape, topography, distribution of boulders and rocks of Bennu with 160M measurements • CSA work together with MacDonald, Dettwiller and Associates Ltd under a $9M contract • 2 transmitters used: o High Energy for altitudes of 1 to 7,5km o Low Energy for altitudes of 500m to 1km • CSA receives 4% of sample in return
- 22. OSIRIS-REx CAMera Suite (OCAMS) • Developed by University of Arizona SamCam MapCam PolyCam
- 23. OSIRIS-REx Thermal Emission Spectrometer (OTES) • Measures emitted spectrum of wavelengths between 5- 50μm with Fourier Transform Spectroscopy • Determine minerals present and thermal inertia of surface • Helps in characterizing Yarkovsky effect and selecting sample site • Built by University of Arizona
- 24. OSIRIS-REx Visible and InfraRed Spectrometer (OVIRS) • Measurements of spectrum with wavelengths 0.4-4.3μm • Linear variable filter, 512x512 HgCdTe detector • Identify volatile and organic-rich regions • Passively cooled such that Tfocal plane = 105K • Assembled and tested at Goddard Space Flight Center
- 25. REgolith X-ray Imaging Spectrometer (REXIS) • Student collaboration experiment between MITs Space Systems Lab and Harvard College Observatory • Measure X-rays from fluorescence effect of regolith with solar wind • Map elemental abundance on Bennu • Resolution better than 50m
- 26. Touch-And-Go Sample Acquisition Mechanism (TAGSAM) and Sample Return Capsule (SRC) • Collect between 60g and 2kg of regolith • Contact surface for about 5s • Annular flow of N2 to fluidize regolith (3 attempts possible) Sample acquisition arm Head of TAGSAM arm
- 27. OSIRIS-REx
- 28. Table of contents • Introduction • Mission objectives • Why Bennu? • Previous research • Instrumentation • Conclusion
- 29. Conclusion • OSIRIS-Rex will return a sample of asteroid regolith by 2023 • Analysis of the organic compound containing sample will provide vital clues to the origine of life on earth • Measurements of Bennu’s surface properties and radiation will help us understand the Yarkovsky effect and how it affects its chance of impact on earth • The mission will undoubtedly unveil many unexpected data and provide information for generations to come
- 30. Raise your hand if you a question
Editor's Notes
- #6: 800m dollar mission, 183M launch, NASA Goddard; UA; Lockheed Martin, 1999 RQ36, Launch in 2016; It wil do a lap around sun, do inclination change at earth + calibrate its instruments,
- #7: 4th mission will be between 2013-2022 chosen, New Horizons = pluto + 2 kuiper belt objects; will reach it in july 2015, Juno = Magnetic field + core of Jupiter; Polar Orbit; launched in 2011; Measure Jovian atmosphere composition to greater depths
- #11: Used to be in asteroid belt, but collision; broke away from family, due to Yarkovsky migrated to become Near Earth Asteroid, contains organic compounds and water
- #17: Bennu heeft 0,07% impact met aarde, beinvloedt door Yarkovsky effect
- #20: The albedo and visible and near-infrared spectrum were compared to a NASA Reflectance Labratory library (RELAB) database of over 15,000 meteorites and was found to match closest to two B-type asteroids, namely the CI and CM type chondrites. These contain organic compounds such as amino acids and nucleobases and likely also water. Rotation period = 4,3 hours, retrograde spin, regolith order of millimeters
- #23: Same receiver
- #24: image Bennu in over 9-orders-of-magnitude of distance from 1 million kilometers to 2 meters. MapCam: field-of-view of 4° and a resolution of less than 1 arc minute, uses a filter wheel, which allows it to take observations in blue, green, red and infrared. MapCam possesses a rotating glass plate which allows it to refocus light from relatively short distances of 30m. PolyCam: 20.3-centimeter wide camera with a 63.5-centimeter focal length. It has a resolution of about one-sixth of an arc minute and a field of view of just less than 1°. Serves as telescope and microscope SamCam: resolution of almost 4 arc minutes and a wide field of view of 21°, SamCam is designed to document sample acquisition. Same detectors but different focal lengths (factor 5)
- #25: - OTES uses a Michelson interferometer to collect one interferogram every two seconds - The field-of-view of the instrument is 8mrad such that from a height of 500m, from which it will make observations for selecting a sample site, it has a spatial resolution of 4m and for the main map at 5km altitude it has a resolution of 40m. - OTES will be fully ready in mid-2015.
- #26: From a height of 5km, the spatial resolution in 20m while at a height of 500m, used for selecting a suited sample site a resolution of 2m.
- #28: Gravitational attraction = 100,000 smaller than earth, harpoons -> Loose gravel!, thrusters -> contamination, 4,3 hours from -150 to +63° -> engineering instruments; SO TAG the surface instead Regolith has to be smaller than 2cm Measure mass of sample by rotating the spacecraft