Navstar 46

 1999-055A

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SV06 (SVN46) was GPS Block IIR flight 3, launched to slot D2.

GPS
Date	Time	Event	Orbit
1999 Oct 7	1251:01	Launch by Delta 7925-9.5	CC LC17A
		T+1:03 SRM 1-6 out
		T+1:05 SRM 7-9 on
		T+1:06 SRM 1-6 sep
		T+2:12 SRM 7-9 sep
		T+4:25 MECO
		T+4:39 SES1
		T+4:55 PLF sep
	1301	T+10:48 SECO1	88.27 175 x 201 x 36.9 (s)
			174 x 180 x 36.9
	1353	T+1:02:34 SES2
	1354	T+1:03:15 SECO2	98.12 187 x 1149 x 37.2 (s)
	1355	T+1:04:05 St 2 sep	97.98 181 x 1142 x 37.22
	1355	T+1:04:44 TES
	1357	T+1:06:09 TECO	357.92 192 x 20448 x 39.0 (s)
	1358	T+1:08:05 St 3 sep

STS-51-C (Discovery)

 1985-010A

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51-C was the first classified mission. No details of the flight were given between ET separation and entry interface. It was thought that both OMS-1 and OMS-2 burns were made, although the mission events list does not include an OMS-1.

If there was an OMS-1, we may conjecture magnitudes similar to other OMS-1/2 burn pairs at around 55-75m/s; I give 4 cases below labelled A to E. The ET impacted further west than on any other mission and so we can assume a lower ET trajectory; case A is not a bad fit to the available data, although the ET impact zone may indicate an even larger OMS-1 burn such as case E.

Available orbital data also shows that an 11m/s OMS-3 burn was made, presumably following payload deployment. AWST reported deployment around 1200 UTC on Jan 25, but the orbital data suggests the OMS-3 burn came at southbound equator crossing around 0656 UTC, with a corresponding deployment at 0645 UTC and IUS SRM-1 burn at northbound equator crossing at 0740 UTC. If the AWST report of 16hr MET deployment is correct, the OMS burn was made before deployment, and the corresponding northbound equator crossing IUS burn is at 1215 UTC with deployment at 1120 UTC. It is then puzzling that there is no evidence of a sep burn.

STS 51-C mission events
Date	Time	Event	Orbit
1984 Dec 21		Roll to VAB/1
1984 Dec 21		ET mate
1985 Jan 5		Rollout	LC39A
1985 Jan 24	1950:00	Launch from LC39A
	1952:07	SRB sep
	1958:32	MECO
	1958:49	ET sep
		A (Assume 75m/s OMS-1, 75m/s OMS-2)	86.07 1 x 157 x 28.5
		B (Assume 65m/s OMS-1, 75m/s OMS-2)	86.40 21 x 169 x 28.5
		C (Assume 55m/s OMS-1, 75m/s OMS-2)	86.73 38 x 185 x 28.5
		D (Assume 65m/s OMS-1, 65m/s OMS-2)	86.73 43 x 181 x 28.5
		E (Assume 80m/s OMS-1, 75m/s OMS-2)	86.07 -10 x 152 x 28.5
	2000	OMS-1 (?)
		(Assume 65m/s OMS-2)	88.93 114 x 328 x 28.5
		(Assume 75m/s OMS-2)	88.69 81 x 328 x 28.5
	2017	ET apogee (case A)
	2000:46	OMS-2	91.18 327 x 337 x 28.5
	2003:47	OMS-2 CO
	2036	ET breakup at 69km
	2220:48	PLBD open
1985 Jan 25	0004		91.23 332 x 337 x 28.5
	0515		91.33 336 x 342 x 28.5
	0635	probable USA-8 deploy
	0651:56	OMS-3, sep?	91.64 334 x 375 x 28.5
	0652:19	OMS-3 CO
	0740	IUS burn, eq crossing N
	1120	Alternate USA-8 deploy (AWST)
	1215	Alternate IUS burn (AWST)
1985 Jan 27	0010		91.66 335 x 376 x 28.5
	1744:06	PLBD closed
	2016:00	OMS DO	88.40 29 x 360 x 28.5
	2019:13	OMS DO CO
	2052:29	Entry
	2123:23	Landed RW15 KSC
	2123:35	NGTD
	2124:15	Wheels stop
1985 Jan 28	0250	Tow to OPF

Explorer 4

  1958-005

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Explorer IV was launched on 1958 Jul 26 by Juno I from Cape Canaveral into a 110.2 min, 263 x 2213 km x 50.3 deg orbit. Its mission was to study both the natural radiation belts at high latitudes and the effects of the Argus high altitude nuclear explosions. It transmitted until Sep 19 and reentered on 1959 Oct 23.

Mass was 16.8 kg, including 11.7 kg for the satellite and 5.1 kg for the motor. The higher mass required a lower injection altitude and higher inclination.

The JPL Cluster used improved propellants in the third and fourth stages. The intended orbit was much more eccentric than previous launches, and used a different inclination. The intended orbit had been 288 x 2824 km x 50.8 deg.

Explorer 4
Date	Time	Event	Orbit
1958 Jul 26	1500:57	Launch by Juno I	CC LC5
		T+2:33 MECO
		T+2:40? Redstone sep
		T+6:02 Stage 2 burn
		T+6:10 Stage 2 cutoff
		T+6:10 Stage 3 burn
		T+6:18 Stage 3 cutoff	-3052 x 287
		T+6:18 Stage 4 burn
	1507:23	T+6:26 Stage 4 cutoff	257 x 2233 x 50.4
		T+10:58 Redstone impact 1475 km
		T+11:36 Stage 2 impact 2086 km
		T+13:36 Stage 3 impact 3317 km
1959 Apr 24			100.99 258 x 1352 x 50.2
1959 Jul 17			98.02 246 x 1080 x 50.3
1959 Oct 2			92.81 239 x 584 x 50.2