Hexagon 1

  1971-056A

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Mission 1201, the first Lockheed Big Bird, was launched on 1971 Jun 15 by the new Titan IIID launch vehicle. It carried the prototype KH-9 camera system, reportedly a pair of Perkin-Elmer Cassegrain telescopes with a focal length of 2.4m and a mirror diameter of 1.5m. Four satellite recovery vehicles were used. The first one was recovered from the sea after a parachute partial failure.On the first day of the mission there was a problem with the battery thermal control due to SRM debris on the satellite surface, but workarounds were found.

During the photo mission the imaging system shut down four times, including three `problems in the film path', but each time the system was successfully restarted.

The satellite operated `solo' for 21 days after the primary mission and was then deboosted. The spacecraft was maintained in a 175-180 km x 280-300 km orbit from Jun 16 to Jul 26, The perigee was then lowered to 147-150 km for a few days; on Jul 31 the vehicle entered a higher 260 x 285 km orbit until it was deorbited on Aug 6.

HEXAGON 1
Date	Time	Event	Orbit
1971 Jun 15	1841	Launch by Titan IIID	V SLC4E
		T+1:53 Stage 1 burn 2:27
		T+1:55 SRM burnout
		T+1:55 SRM sep
		T+4:16 Stage 1 MECO
		T+4:16 Stage 1 sep
		T+4:16 Stage 2 burn
		T+5:05? Fairing
		T+7:44? Stage 2 MECO
	1849	T+8:00? Stage 2 sep
1971 Jun 16	0305		89.31 182 x 298 x 96.4
1971 Jun 20	2045?	SRV-1 eject, rev 82
	2115	SRV-1 sea recovery
		Rev 88, photo ops resume
1971 Jun 22	1053		89.14 178 x 285 x 96.4
		Orbit raise
1971 Jun 23	1806		89.27 179 x 297 x 96.4
1971 Jun 26	2102	SRV-2 eject, rev 179
	2135	SRV-2 mid-air recovery
		Rev 185, resume imaging
1971 Jun 27	0525		89.15 176 x 288 x 96.4
		Orbit raise
	1550		89.24 176 x 297 x 96.4
1971 Jul 1	0606		89.10 175 x 284 x 96.4
		Orbit raise
	1800		89.29 180 x 297 x 96.4
1971 Jul 9	0430		89.09 178 x 280 x 96.4
		Orbit raise
1971 Jul 10	2114?	SRV-3 eject, rev 405
	2142?	SRV-3 ocean impact
1971 Jul 10	2041		89.27 178 x 298 x 96.4
1971 Jul		ESD (safemode) problems
1971 Jul 14	2000?	Rev 470, resume imaging
1971 Jul 16	0734		89.07 174 x 282 x 96.4
	0946	SRV-4 eject, rev 502
	1015	SRV-4 mid-air recovery
		End of photo operations
		Orbit raise
1971 Jul 17	1018		89.24 182 x 291 x 96.4
1971 Jul 20	0936		88.99 173 x 275 x 96.4
		Orbit raise
	1702		89.02 179 x 272 x 96.4
1971 Jul 21	0623		88.80 177 x 252 x 96.4
		Orbit adjust
	2112		88.97 173 x 272 x 96.4
1971 Jul 23	1017		88.89 170 x 267 x 96.4
		Orbit raise
1971 Jul 24	0238		89.32 181 x 300 x 96.4
1971 Jul 25	1250		89.02 182 x 269 x 96.4
		Orbit raise
	1847		89.25 181 x 293 x 96.4
		Orbit lower
1971 Jul 26	1830		88.58 147 x 261 x 96.4
		Orbit adjust
1971 Jul 28	1448		88.70 151 x 268 x 96.4
1971 Jul 29	1130		88.55 150 x 254 x 96.4
1971 Jul 30	2129		88.75 134 x 290 x 96.4
		Orbit raise
1971 Jul 31	1652		89.96 261 x 283 x 96.4
1971 Aug 3	0323		89.95 258 x 285 x 96.4
		Orbit raise
	0624		90.03 266 x 285 x 96.4
1971 Aug 4	0155		90.02 262 x 288 x 96.3
1971 Aug 6		Reentered after 52 days