Geosat

 1985-021A

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APL's Geosat obtained altimetry data for Trident missile targeting between Mar 1985 and Oct 1986, completing mapping of the marine geoid begun by Seasat. It achieved a spatial resolution of 15 km. It then altered its orbit to begin the Seasat Exact Repeat Mission, which involved having 17-day repeating groundtracks, suitable for oceanography.

Geosat 1
Date	Time	Event	Orbit
1985 Mar 13	0200	Launch by Atlas E (41E)	V
		T+2:01? BECO
		T+2:04? Booster sep
		T+2:24? Fairing
		T+5:24? SECO
		T+5:49? Atlas sep	-2270? x 800 ? x 108?
	0211??	T+11 min? Star 27 burn
	0211??	Star 27 sep	100.64 760 x 817 x 108.05
	0215?	Restraining cable release
		Despin cable release
		Deploy solar panels
		Deploy boom 1m
1985 Mar 14		Deply boom fully
1985 Mar		Geodetic mission (GM) begins
1985 May 5			100.63 759 x 817 x 108.07
1986 Sep 22			100.63 762 x 814 x 108.04
1986 Oct 1		End of GM
		2 test burns
1986 Oct 3		Calibration burn
1986 Oct 7		Calibration burn
1986 Oct 10-11		30 burns to alter e and arg. peri.
1986 Oct 14			100.63 762 x 814 x 108.04
1986 Oct 14-23		157 burns to alter e and arg. peri.
1986 Oct 23			100.62 772 x 802 x 108.02
1986 Oct 23		Start 48 burns to alter semimajor axis
1986 Oct 27			100.59 783 x 789 x 108.03
1986 Nov 7		End of 48 burns
1986 Nov 7		Secondary mission begins: Seasat ERM (Exact Repeat Mission)
1986 Nov 8			100.59 785 x 788 x 108.03
1986 Dec 1?		Alter period by 22ms
1987		Adjust orbit by 20ms every 30d
1988 Nov 23			100.59 784 x 788 x 108.04
1989 Oct 3		Tape recorders failed
1990 Jan 5		end of tx
1990 Oct 21			100.56 783 x 786 x 108.05
1996 Mar 4			100.44 775 x 781 x 108.05
2002 Mar 20			100.26 768 x 773 x 108.05