HEAO 1

 1977-075A

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HEAO A was the first in the series. Laucnhed on 1977 Aug 12 at 0629 by an Atlas Centaur from Cape Canaveral, High Energy Astronomy Observatory 1 was inserted in a 93.2 min, 428 x 447 km x 22.8 deg. HEAO 1 carried out an all-sky survey in hard x-rays with its four instruments. On 1979 Jan 8 the attitude control fuel ran out, and the satellite stopped transmitting two days later. It reentered on 1979 Mar 15.

HEAO 1
Date	Time	Event	Orbit
1977 Aug 12	0629:31	Launch	CC LC36
		T+2:10 BECO
		T+2:23 Booster sep
		T+3:05 Insulation panels sep
	0633:42	T+4:11 SECO
	0633:44	T+4:13 Atlas sep
		T+4:23 Centaur MES-1
		T+4:35 Fairing
	0641:18	T+11:47 MECO
	0652:23	T+22:52 Centaur sep
	0652:33	T+23:02 Centaur retro
		T+1:13:17 Centaur blowdown
1979 Jan 8		RCS fuel expended
1979 Jan 10		end of operations
1979 Mar 15		Reentered