Exosat

 1983-051A

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The EXOSAT X-ray astronomy satellite was built by the MBB-led COSMOS consortium for ESA, with structure by SNIAS-Cannes. It followed up the results of the Einstein observatory with hard X-ray spectroscopy and limited soft band imaging. The ME instrument was the most productive with many low resolution X-ray spectra of binary stars and active galaxies. It was controlled from Villafranca.

The spacecraft was launched in May 1983 by Delta from Vandenberg; the launch was switched from Ariane after failures; it was originally to use an Ariane 1 with a P0.68 fourth stage. The unusual highly elliptical orbit was intended to allow accurate position determination using lunar occultation, but by the time Exosat was orbited the technique was not as useful as it would’ve been. However, the high orbit was very successful in permitting long uninterrupted observations of variable sources.

Exosat
Date	Time	Event	Orbit
1983 May 26	1518	Launch by Delta 3914	V SLC2
		T+0:59 SRM 1-6 burnout
		T+1:00 SRM 7-9 burn
		T+1:18 SRM 1-6 sep
		T+2:00 SRM 7-9 burnout
		T+2:00 SRM sep
		T+3:46 MECO
		T+3:55 St 1 sep
		T+4:00 SES-1
		T+4:04 Fairing sep
	1526	T+8:42 SECO-1	176 x 472 x 72.5
	1556	T+38:36 SES-2 27s
	1557	T+39:02 SECO-2	337 x 1633 x 72.4
	1557	T+39:46 St 2 sep
	1558	T+40:29 TES
	1559	T+41:12 TECO
	1600	T+42:37 Yoyo deploy
	1600	T+42:49 St 3 sep	356 x 191581 x 72.4
			347 x 188301 x 72.46 (MOR)
	1613	T+55:41 SES-3 depletion
	1613	T+55:49 SECO-3	119.94 755 x 2529 x 72.32
1983 May 27	1056	Pass EL1:4
1986 Apr 9		end of ops
1986 May 6	1445?	reentered