OSIRIS-REx Frequently Asked Questions

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1 OSIRIS-REx Frequently Asked Questins What is the OSIRIS-REx Missin? The OSIRIS-REx missin is NASA New Frntiers missin t return a sample f an asterid t the Earth. Missin cst is apprximately $800 millin (excluding the launch vehicle.) The OSIRIS-REx missin is a partnership f the University f Arizna, NASA s Gddard Space Flight Center and the Lckheed Martin Cmpany. Additinal wrldwide partners and cllabratrs will prvide scientific instruments and supprt missin science. The OSIRIS-REx spacecraft launches in 2016, rendezvus with asterid (101955) Bennu in 2018 and returns its sample t Earth in What des OSIRIS-REx Stand Fr? OSIRIS-REx is an acrnym that describes the wrk f the missin: Origins The missin will return a pristine sample t Earth t help us understand the rigins f vlatiles and rganics that may have seeded life n Earth. Spectral Interpretatin Instruments will map the prperties f the asterid in the search fr mineral and rganic substances. Resurce Identificatin The missin will identify asterid resurces that might be used in future missins t the uter slar system, in additin t identifying resurces f ecnmic value. Security Measurements will quantify the rle f the Yarkvsky Effect n this ptentially hazardus asterid, helping t secure the Earth frm future asterid impacts. Reglith Explrer The missin will explre the reglith at the sampling site in situ at subcentimeter scales.

2 What will the OSIRIS-REx Missin D? The OSIRIS-REx missin will thrughly characterize near-earth asterid (101955) Bennu. Asterids are the direct remnants f the riginal building blcks f the terrestrial planets. Knwledge f their nature is fundamental t understanding planet frmatin and the rigin f life. The return t Earth f pristine samples with knwn gelgic cntext will enable precise analyses that cannt be duplicated by spacecraft-based instruments, and will revlutinize ur understanding f the early Slar System. What are the OSIRIS-REx missin's scientific bjectives? The missin s scientific bjectives are: 1. Return and analyze a sample f pristine carbnaceus reglith 2. Map glbal prperties, chemistry, and mineralgy f the asterid 3. Investigate texture, mrphlgy, vlatile chemistry, and spectral prperties f the reglith 4. Measure the Yarkvsky effect 5. Prvide direct cmparisn t telescpe-based data f the entire asterid ppulatin. Why asterid (101955) Bennu? (101955) Bennu is an exciting, accessible, vlatile and rganic-rich remnant frm the early Slar System, as well as ne f the mst ptentially hazardus asterids knwn. Bdies frm the uter main asterid belt are believed t be the dminant surce f primrdial terrestrial rganics and pssibly water. In the chatic early Slar System, many cllided with the yung planets bringing rganics and pssibly water t them. Water and carbn are the building blcks f life n Earth. Bennu likely has abundant reglith, cmprised f fine gravel (4-8 mm) which is ideal fr cllecting a sizable sample. With this sample, scientists will be able t analyze the asterid s cmpsitin, mineralgy, and gelgy t learn mre abut it and ther asterids. Every six years, Bennu s rbit brings it near the Earth less than 449,000 km (~280,600 mi). Its rbit gives Bennu ne f the highest impact prbabilities with Earth f any knwn asterid. OSIRIS-REx will help scientists better determine the rbit f the asterid t prvide mre cnclusive data n what kind f threat it represents. With time, plicymakers will be able t decide what (if any) steps shuld be taken t mitigate the risk f impact. T find the current psitin f Bennu, g t Fr mre n near-earth asterids and impact hazards, g t Mapping the characteristics f the asterid with instruments during rendezvus ( ) the OSIRIS-REx spacecraft will nt nly determine the ptimum sampling site but als btain imprtant

3 data abut cmpsitin and behavir. Scientists will determine tpgraphy, cmpsitin, and rbital characteristics. Bennu is a B-type asterid. B-type asterids are carbnaceus, rich in vlatiles and pssible representatives f asterids that brught seeds f life t Earth. Telescpic bservatins f Bennu have allwed scientists t refine the rbit f the asterid t a great extent, but the rendezvus with the asterid will allw mre precise determinatin f the frces that affect its rbit. This missin will measure the Yarkvsky effect t understand Bennu s rbit and mechanics that affect ther Near Earth Object rbits. What is a Near-Earth Object? A Near-Earth Object is a cmet r asterid rbiting the Sun in the neighbrhd f the Earth. Mst asterids reside in the asterid belt between Mars and Jupiter. Abut 600,000 main belt asterids are knwn. Over 8,000 near-earth bjects have been fund. An bject becmes an NEO because the gravitatinal attractin f planets (primarily the very large and massive Jupiter) have nudged it int an rbit that brings it int Earth s vicinity. Anther factr is the Yarkvsky Effect. What is the Yarkvsky effect? In 1902, Ivan Yarkvsky suggested that the daily heating f an bject rtating in space culd exert a small frce n the bject. We knw hw the temperature n Earth gets warmer and warmer as the Sun rises, hitting a maximum smetime in the early afternn. The same thing ccurs n an asterid. When the heated surface f Bennu pints its ht afternn side in the directin f its mtin arund the Sun - the escaping radiatin acts like a tiny rcket thrust, slwing it dwn and sending it clser t the inner slar system. Althugh tiny, this cnstant push can change an asterid s rbit significantly. The OSIRIS-Rex missin will carefully study the Yarkvsky effect n Bennu, which shuld help scientists imprve their ability t predict the rbits f ther threatening asterids. What d we knw abut (101955) Bennu? (101955) Bennu is a near-earth bject. It cmpletes an rbit f the Sun every days (1.2 years). This rbit takes it clse t the Earth every six years. Althugh the rbit is reasnably well knwn, scientists cntinue t refine it. It is critical t knw the rbit f Bennu because recent calculatins prduce abut a 1 in 2000 chance f impact with Earth in the year Part f the OSIRIS-REx missin is t refine ur understanding f the frces n Bennu s rbit and t refine the calculatins f the future threat t Earth.

4 Telescpic bservatins have revealed sme basic prperties f Bennu. They indicate that Bennu is very dark. Such asterids are cnsidered primitive, having undergne little chemical alteratin since the beginning f the slar system. Why a sample return missin? What we knw f asterids, we have learned thrugh telescpic bservatins and frm labratry analysis f meterites, the recvered fragments f asterids that fall t Earth. Telescpic bservatins can tell scientists a lt abut these very dim bjects, including their mass, density, rtatin and likely cmpsitin. Frm meterite analyses, researchers can determine cmpsitin, density, mass and create mdels f the parent bdies and their frmatin and histry. Telescpic bservatins, lab analyses and mdels can be linked by bringing a physical sample f an asterid back t the lab. Frm such studies, scientists will be able t cnfirm the facts with an actual field check! Finally, bringing a sample t Earth will allw scientists t study Bennu using instruments and techniques that are far mre sphisticated than culd ever be flwn n present-day spacecraft. Samples will be als archived fr future study by advanced instruments that can nly be dreamed f tday. What are the characteristics f the spacecraft and what is its paylad? Lckheed Martin will build the spacecraft and use prven technlgies and designs frm Stardust, a NASA sample return missin that flew past a cmet in Other partners will build the science instruments fr the missin.

5 Spacecraft Details The OSIRIS-REx spacecraft is apprximately 2 m (6.6 ft) n each side. Active slar arrays are 8.5 square meters (91 square feet). Slar energy charges Li-in batteries, which pwer the OSIRIS-REx spacecraft and instruments. The Sample Return Capsule (SRC) is the same as used in the Stardust missin. Innvative sampling methds using the Tuch and G Sample Acquisitin Mechanism (TAGSAM): Appraches surface at 0.1 m/secnd (3.93 inches/secnd), fluidizes reglith and cllects sample in apprximately 5 secnds, cllects a minimum f 60 g (2.1 unces), has cntinuus imaging f sampling, verifies sample amunt by measuring change in the spacecraft inertia Instruments A suite f instruments flies n bard the spacecraft t prvide infrmatin necessary t carry ut the science and select the sampling site. OSIRIS-REx Camera Suite (OCAMS) This suite cnsists f Ply Cam, MapCam, and SamCam, which prvide lng-range acquisitin f Bennu and imaging f its surface dwn t millimeter ranges, alng with glbal mapping, sample-site characterizatin, and sample acquisitin dcumentatin. The University f Arizna is building OCAMS. OSIRIS-REx Laser Altimeter (OLA) Prvides glbal and tpgraphic mapping f candidate sample sites. The Canadian Space Agency is building OLA. OSIRIS-REx Visible and IR Spectrmeter (OVIRS) Prvides mineral and rganic spectral maps and lcal spectral infrmatin f candidate sample sites frm micrns. NASA Gddard Space Flight Center is building OVIRS.

6 OSIRIS-REx Thermal Emissin Spectrmeter (OTES) Prvides mineral and temperature data f candidate sample sites frm 5-50 micrns. Arizna State University is building OTES. REglith X-ray Imaging Spectrmeter (REXIS) A student cllabratin experiment x-ray ( kev) telescpe prvides glbal mapping f elemental abundances and dcumentatin f sampling site. MIT and Harvard are building REXIS. What precautins will be taken t lwer the prbabilities f bringing hme cntaminated material? NASA has stringent prtcls t ensure that its missins d nt transprt threatening materials t Earth. An internatinal treaty gverns NASA s activities related t planetary prtectin. NASA s OSIRIS- REx missin fllws these prtcls and all related requirements t prevent cntaminatin f the Earth and ther Slar System bdies. These prtcls include requirements fr bth the spacecraft and fr any returned samples. Fr mre infrmatin see Many tns f material frm asterids, cmets and beynd land n Earth every day. As they pass thrugh the atmsphere, they are called meters. Althugh meters d heat up as they pass thrugh the Earth s atmsphere, their interirs remain cld even while the utside is ht. Cnsequently, meterite interirs are nt sterilized as they travel thrugh Earth s atmsphere. Expsure t radiatin and heat in interplanetary space can sterilize materials. The OSIRIS-REx missin target asterid, (101955) Bennu, is very ld and has had many clse appraches t Earth. Scientists believe that these encunters have rearranged its structure, mving materials frm its interir t its surface and back. Because Bennu is s dark the surface gets quite warm (up t 170 F). As the asterid mves thrugh space, its surface has been subjected t enugh heat and slar and galactic radiatin t kill many Earth rganisms. S even if cnditins were right fr life t riginate n Bennu (which is highly unlikely), it wuld have been irradiated, cked, and have few places t hide. Where can I get mre infrmatin? Visit the OSIRIS-REx website at