OSIRIS-REx

 2016-055A

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New Horizons mission 3.

OSIRIS-REx will use an N2 gas gun to collect at least 0.06kg of asteroid samples in a US analog to the Hayabusa mission. The acronym is for Origins. Spectral Interpretation, Resource Identification, Security-Regolith Explorer.

PI is M. Drake, U Arizona, with project science office at GSFC. Discovery/NewFrontiers program office is at MSFC. Mass is 2110 kg full 880 kg dry.

The SRC is based on the Stardust design and is 0.50m high 0.81m dia.

Goal is to collect 2 kg of sample, but at least 0.06 kg. TAGSAM sampler can make 3 attempts, touching surface for 5 seconds and using a burst of N2 gas to kick loose surface material into the collector.

SC size 2.4 x 2.4m x 3.2m box + 2 panels, 6.2m span. The TAGSAM is 3.4m long. SRC mass 46 kg.

Bennu is 492 m (+-20m) mean diameter and rotates in 4.3 hr. Estimated Bennu mass is 78 gigatonnes. At encounter, Bennu is 1.30 AU from Sol. Its Hill radius is then 46 km. This drops to 35 km when Bennu is at 1.0 AU in Nov 2018, 32 km at perihelion in Jan 2019, and back up to 47 km by aphelion in Jul 2019. OSIRIS-Rex planned departure is Mar 2021 when R-Hill is 39 km.

Launch by Atlas V 411 with RL10A-4-2-engined Centaur.

OSIRIS-REx
Date	Time	Event	Orbit
2016 Sep 8	2305:00	Launch by Atlas V 411 AV-067	CC
		T+2:19 SRB sep
		T+4:03 BECO
	2309	T+4:09 Atlas sep
		T+4:19 MES-1
		T+4:27 Fairing sep
	2317	T+12:22 MECO-1	165 x 272 x 26.96
	2334		161 x 289 x 26.98
	2342:10	T+37:10 MES-2 6:50
	2349:00	T+40:38 MECO-2
2016 Sep 9	0004	T+59:05? Centaur sep
		C3 = 29.30 (5.4 km/s)**2
		DSM-1,2 0.52 km/s
		T+1:28:58 Centaur blowdown
		T+1:56:58 Centaur blowdown end
	0620?	Pass EL1:4
2016 Sep 12	0139	Min L1 dist of 190080 km
2016 Sep 12	0210?	Pass L1
2016 Oct 7	1700	TCM-1 12s, 0.5m/s, 0.5 kg; range 14.5Mkm
2016 Oct 12			0.776 x 1.167 AU x 0.2
2016 Dec 28		TCM-2 DSM-1 431.2m/s 345 kg
2017 Jan 18	1806	TCM-2a 2.6m/s
2017 Aug 23	1700	TCM-3 77s 0.5m/s 0.5kg
2017 Sep 19	2347	Enter E sphere
2017 Sep 22	1651:45	Gravity assist, increase incl.	17217 x -50522 x 84.8
2017 Sep 25	0849	Depart E sphere
2018 Feb 12		TAG maneuver practice
2018 May?		DSM-2
2018 Aug		Begin approach phase, 2 M km at 1.24AU
		Braking burns 0.53 km/s
2018 Aug 17		Rendezvous with (101955) 1999 RQ36 Bennu
2018 Oct		Prelim Survey
		Orbital A
		Detailed Survey
		Orbital B
2019 Mar 18		OLA topo mapping
2019 Jul 22		0.2m/s descent orbit burn to contact Bennu at vrel of 0.10m/s.
		Collect samples to SRC
2021 Mar 3		Depart asteroid at 0.32 km/s
2023 Sep 24		E-4:00:00 SRC sep
		E-3:40:00 17.5m/s EDM deflect to solar orbit
		E+0 Earth entry 12.2 km/s -8.2 deg Az 62, spin at 13 rpm
		E+0:02:15 Para deploy 33 km drogue; sabot/canister cover sep
		3 km, drogue sep
		E+7:36 3 km, 7.3m main para deploy
		E+13:30 Land in Utah UTTR (80 x 25 km target ellipse)
		SC perigee	200 x Inf
		SC in solar orbit	0.5 x 1.0 AU

Payload:

• REXIS Regolith X-ray Imaging Spectrometer, soft X flourescence element abundance mapping 0.3-7.5 keV with 64 x 64 pixel coded mask, 21' resolution. (MIT/Harvard/Miller,Binzel,Seager,Grindlay)

• OLA Osiris-Rex laser altimeter (LIDAR). Low and high energy laser transmitters covering 0.5 to 7.5 km range. (CSA/Calgary/Hildebrand)

• GN&C; LIDAR range camera, for control during TAG operations.

• TAGCAMS Touch and Go Camera System; 2 NavCams for optical navigation; 2 x 5 Mpix ECAM-M50 plus 1 StowCam to verify proper stowage. (Malin/)

• TAGSAM sampler (Touch-and-Go Sample Acquisition Mechanism), robotic arm with sampler head

• OVIRS OSIRIS-REX Vis and IR Spectrometer. Res 20m for survey, 2m for sample site. 0.4-4.3mu. (GSFC/Reuter)

• OCAMS O-REX Camera Suite (Arizona/Rizk)

  • MAPCAM 4 color mapping camera, 1m res

  • PolyCam 0.20m telescope for distance imaging.

  • SamCam Sample camera , 1.6s cadence, mm scale