Hexagon 13

 1977-056A

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SV-13 was the first Block III vehicle, with increased propellant capacity and improved batteries.

The spacecraft carried a supplementary Space Test Program experiment, the S76-1 NAVPAC autonomous navigation experiment. NAVPAC combines an accelerometer and Transit NNS receivers to derive the spacecraft's orbit.

The mapping camera operated until Oct 17, with the doppler beacn shut down on Oct 21. On Nov 6 the orbit was raised from 156 x 240 km to 158 x 265 km for the remainder of the mission, which ended on Dec 23.

HEXAGON 13
Date	Time	Event	Orbit
1977 Jun 27	1830	Launch by Titan IIID	V SLC4E
		T+1:49? 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
	1837?	T+7:44? Stage 2 MECO
	1838?	T+8:00 Stage 2 sep
1977 Jun 27			88.43 155 x 239 x 97.0
1977 Jul 10			88.43 154 x 238 x 97.0
1977 Aug 1			88.33 154 x 229 x 97.0
1977 Aug 2	2143?	SRV-1 MAR
1977 Aug 3			88.51 156 x 244 x 97.0
1977 Aug 31			88.50 155 x 245 x 97.0
1977 Sep 5	2125?	SRV-2 water recovery
1977 Sep 29			88.38 158 x 229 x 97.0
1977 Oct 15			88.59 159 x 250 x 96.9
1977 Oct 17		Map op 253 last image
1977 Oct 18	2150?	SRV-5 deorbit opp
	2225?	SRV 1213-5 recovered after 113d
1977 Oct 21		DB-16 turned off
1977 Nov 1			88.48 157 x 241 x 96.99
1977 Nov 4	2225?	SRV-3 deorbit
1977 Nov 5	1236		88.27 153 x 225 x 96.9
		Perigee at 222 58
	1905?	Orbit raise	158 x 262
		Perigee at RA DEC = 216 35
		Apogee at RA DEC = 36 -35
1977 Nov 6	2236		88.71 158 x 262 x 96.9
1977 Nov 30			88.74 157 x 266 x 96.9
1977 Dec 6	0501		88.79 158 x 271 x 96.9
1977 Dec 19	2155?	SRV-4 MAR
1977 Dec 22	2317		88.63 159 x 254 x 96.9
1977 Dec 23		NAVPAC-1 turned off
1977 Dec 26	2200?	Deboost over Pacific