SERT 2

  1970-009A

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The SERT II spacecraft was 7.9m long and built around the Lockheed Agena D spacecraft, used as the upper stage of the Long Tank Thrust Augmented Thor Agena D launch vehicle. The payload at the front end of Agena 6111 was built by NASA-LeRC and contained two ion thrusters. The span across solar panels was 12.7m.

Launch was on 1970 Feb 4 from Vandenberg; the spacecraft entered a 105.2 min, 997 x 1003 km x 99.1 deg orbit. Thruster 1 was operated first, until 1970 Jul 23 when it shut down and Thruster 2 was started. On 1970 Oct 17 Thruster 2 also shorted and shut down, and NASA declared the mission as a failure in Dec 1970. The spacecraft itself was deactivated in Jan 1972. It was reactivated for a while from May to Sep 1973, and then in the summer of 1974 Thruster 2 started working again when the spacecraft was reoriented to get more power to the solar arrays. In 1980 SERT II was again reactivated and the ion thrusters were fired until the propellant supply was depleted. The satellite was turned off in 1981, but reactivated once again in 1988. In 1989 Jun full control was regained and micrometeor data was received. After deactivation for an eclipse phase from 1989 Dec to 1990 Jun, SERT II was reactivated once more and finally switched off in 1991 Nov.

SERT 2
Date	Time	Event	Orbit
1970 Feb 4	0259:50	Launch by Thorad Agena D
		T+0:38 SRM out
		T+1:42 SRM sep
		T+3:44 MECO
		T+3:53 VECO	-5496 x 148 x 96.40
		T+3:59 Thorad sep
		T+4:19 Agena 6111 MES-1, 232s
		T+4:29 Fairing sep
	0308:02	T+8:12 Agena MECO	155 x 1000 x 99.12
	0355:47	T+55:57 Agena MES-2, 3s
	0355:52	Agena MECO-2
			105.2 997 x 1003 x 99.1
	0445:42	Solar array deploy
1970 Jul 23		Thruster 1 shutdown
1970 Jul		Thruster 2 test
1970 Oct 17		Thruster 2 short
1972 Jan		Deactivated
1973		Reactivated
1981		Turned off
1988		Reactivated
1991 Nov		Decommissioned