July 7,2019

 https://planet4589.org/space/jsr/back/news.766.txt

GRAIL

 2011-046A

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DISCOVERY mission, lunar equivalent of GRACE. Gravity Recovery and Interior Laboratory. Managed by JPL, with PI MIT/Maria Zuber. Lockheed Martin/Denver satellites based on XSS-11 bus with Ka-band rangers.

Each satellite is a box 1.1m high 0.95m wide 0.76m deep. Mass is 307 kg wet, 201 kg dry. Launch by Delta II 7920H-10C.

On 2011 Jan 17, GRAIL-A was renamed Ebb and GRAIL-B was renamed Flow.

In operational phase, orbits from 51 to 16 km. In early April at circular phase, minimized solar perturbations and avoided momentum dumps for maximal sensitivity to lunar core parameters. Orbit determined to 20 cm accuracty; determined that 98 percent of lunar gravity variation is due to surface topography rather than deep interior, and distinguished true lunar basins from many postulated but spurious ones.

GRAIL 1
Date	Time	Event	Orbit
2011 Sep 10	1308:52.8	Launch by Delta 7920H	CC LC17B
		99 deg az
		T+1:20 SRM 1-6 burnout
		T+1:20? SRM 7-9 on
		T+2:40?	SRM 7-9 out
		SRM 1-9 sep
		T+4:23 MECO
		St 1 sep
		SES-1
	1316	T+7:10 SECO-1	167 x 167 x 29.2?
			155 x 175 x 29.3
		1 hr coast
	1414:44	T+1:05:51 SES-2 (TLI) 272s
	1419:16	T+1:10:23 SECO-2	175? x 1129400? x 29.2?
	1428:46	T+1:19:53 S2+9:30, Grail-A sep
	1434	Solar arrays deployed
			174 x 1108206 x 29.3
	1436	T+1:28:08 S2+17:45, Grail-B sep C3=-0.70
			173 x 1109774 x 29.3
	1442	Solar arrays deployed
	1508:02	T+1:59:10 SES-3 depletion
2011 Sep 11	0057	Stage 2 pass EL1:4
2011 Sep 11	0358	Pass EL1:4
2011 Sep 12	0009	Stage 2 orbit	1274 x -179292 x 29.3
2011 Sep 16		A TCM-1
2011 Sep 17	0730	Stage 2 at 1.5Mkm
2011 Sep 23		1 Mkm from Earth
		Coast to Sun-Earth L1
2011 Sep 30	1043	Pass GSEx 1.2Mkm
2011 Sep 30		A TCM-2
2011 Oct 5		B TCM-2
		Translunar coast
2011 Nov 1		Stage 2	347.32d 0.879 x 1.055 AU x 0.01
2011 Nov 21?		TCM B3
2011 Nov 22	0814	Inside GSEx 1.2Mkm
2011 Dec 14?		TCM B4
2011 Dec 25?		TCM B5
2011 Dec 30	0938	Enter L sphere
2011 Dec 31	2121	LOI Grail-A 40min
		burn over S pole, 191 m/s
	2201	LOI complete
		11.5 hr insertion orbit
2012 Jan 1	2205	LOI Grail-B 39min
	2244	LOI complete
2012 Jan 2		OPR phase - Orbit Period Reduction
2012 Feb 6		TSF phase - Transition to Science Formation
2012 Mar 7	0115	Science phase begins, sep at 80 km
		Science orbit 25 x 86 km
2012 Apr 8			55 x 55 k
2012 Apr 21		Sep at 220 km, Trim to reverse drift
2012 May 20			20 x 90 km
2012 May 29		End of primary mission
2012 May 29		Science instruments off
2012 May 30		Orbit adjust
2012 Aug		Science instruments on
2012 Aug 31		Extended mission 23 km avge	15 x 35 km
2012 Nov 2?		Orbit	7 x 40 km
2012 Nov 28		Decommissioning, 40 days	15 x 55 km
2012 Dec 6		lower orbit, Endgame phase	2 x 40 km
2012 Dec 14		Science instruments off
2012 Dec 14		A TCM for impact
2012 Dec 17	2139	A depletion 4:03
		Impact 1.7 km/s 1 deg	-8? x 40? x 90
2012 Dec 17	2228:51	A Impact 75.62N 26.63W
		Sally K Ride Impact Site
		on S face of mountain near Goldschmidt Crater
2019 Jan 1		Stage 2	346.6d 0.877 x 1.054 AU x 0.01

Payload:

• Lunar Gravity Ranging System (USO, Ka-band microwave system) (MIT/Zuber)

• MoonKAM (Ecliptic/UCSD/)

2011-046B

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GRAIL 1
Date	Time	Event	Orbit
2011 Sep 10	1308:52.8	Launch by Delta 7920H	CC LC17B
		99 deg az
		T+1:20 SRM 1-6 burnout
		T+1:20? SRM 7-9 on
		T+2:40?	SRM 7-9 out
		SRM 1-9 sep
		T+4:23 MECO
		St 1 sep
		SES-1
	1316	T+7:10 SECO-1	167 x 167 x 29.2?
			155 x 175 x 29.3
		1 hr coast
	1414:44	T+1:05:51 SES-2 (TLI) 272s
	1419:16	T+1:10:23 SECO-2	175? x 1129400? x 29.2?
	1428:46	T+1:19:53 S2+9:30, Grail-A sep
	1434	Solar arrays deployed
			174 x 1108206 x 29.3
	1436	T+1:28:08 S2+17:45, Grail-B sep C3=-0.70
			173 x 1109774 x 29.3
	1442	Solar arrays deployed
	1508:02	T+1:59:10 SES-3 depletion
2011 Sep 11	0359	Pass EL1:4
2011 Sep 12	0009	Stage 2 orbit	1274 x -179292 x 29.3
2011 Sep 16		A TCM-1
2011 Sep 17	0730	Stage 2 at 1.5Mkm
2011 Sep 23		1 Mkm from Earth
2011 Sep 30		A TCM-2
2011 Sep 30	1150	B pass GSEx=1.2Mkm
2011 Oct 5		B TCM-2
		Coast to Sun-Earth L1
		Translunar coast
2011 Nov 1		Stage 2	347.32d 0.879 x 1.055 AU x 0.01
2011 Nov 21?		TCM B3
2011 Nov 4	0637	B inward of GSEx=1.2Mkm
2011 Dec 14?		TCM B4
2011 Dec 25?		TCM B5
2011 Dec 31	1019	Grail-B in L Sphere
2011 Dec 31	2121	LOI Grail-A 40min
		burn over S pole, 191 m/s
	2201	LOI complete
		11.5 hr insertion orbit
2012 Jan 1	2205	LOI Grail-B 39min
	2244	LOI complete
2012 Jan 2		OPR phase - Orbit Period Reduction
2012 Feb 6		TSF phase - Transition to Science Formation
2012 Mar 7	0115	Science phase begins, sep at 80 km
		Science orbit 25 x 86 km
2012 Apr 8			55 x 55 k
2012 Apr 21		Sep at 220 km, Trim to reverse drift
2012 May 20			20 x 90 km
2012 May 29		End of primary mission
2012 May 29		Science instruments off
2012 May 30		Orbit adjust
2012 Aug		Science instruments on
2012 Aug 31		Extended mission 23 km avge	15 x 35 km
2012 Nov 2?		Orbit	7 x 40 km
2012 Nov 28		Decommissioning, 40 days	15 x 55 km
2012 Dec 6		lower orbit, Endgame phase	2 x 40 km
2012 Dec 14		Science instruments off
2012 Dec 14		B TCM for impact
2012 Dec 17	2139	B depletion 5:07
		Impact 1.7 km/s 1 deg	-8? x 40? x 90
2012 Dec 17	2229:21	B Impact 75.62N 26.63W
		Sally K Ride Impact Site
		on S face of mountain near Goldschmidt Crater

Women Spacefarers: Sixty Different Paths to Space

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