Explorer 43

  1971-019A

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IMP I (Interplanetary Monitoring Platform I) was launched 1971 Mar 13 at 1615 by Delta M6 from Kennedy. Orbit insertion at 1709 was into a 353 x 204577 km x 28.8 deg orbit. Explorer 43 transmitted until reentry on 1974 Oct 2. Orbital perturbations drove the perigee upward for two years, reaching a maximum of 14000 km, and then downward until reentry.

IMP 6
Date	Time	Event	Orbit
1971 Mar 13	1615:00	Launch by Delta L1	CK
		T+0:31 SRM 4-6 (Castor 2) on
		T+0:43 SRM 1-3 (Castor I) out
		T+1:10 SRM 4-6 off
		T+1:20 SRM 1-6 sep
	1618:37	T+3:37 MECO
		St 1 sep
		T+3:47 SES-1 6:07
		T+4:11 Fairing sep
	1625:03	T+10:03 SECO-1 246 km 7.754 km/s	241 x 270? x 28.7
	1708:04	T+53:04 SES-2 77.8m/s
	1708:09	T+53:09 SECO-2 240 km 7.845 km/s
	1708:41	T+53:41 St 2 sep	241 x 544 x 28.7
	1708:55	T+53:55 TES 41s
	1709:39	T+54:39 TECO
	1711:20	T+56:20 Stage 3 sep
	1715?	Yoyo despin
1971 Mar 13			353 x 204577 x 28.8
			242 x 205998 x 28.59 (TR1022)
			241 x 206049 x 28.6 (MOR Post)
			243 x 206258 x 28.69 (FirstYrRpt)
1971 Mar 14		Spin axis perpendicular to ecliptic
1971 Mar 17	1710	X,Y antennae to 1m
1971 Mar 21	2030	X,Y ant to 2m
1971 Mar 25	2350	X,Y ant to 3m; Z to 3m
1971 Mar 30	0815	X,Y to 19m
1971 Mar 31		Chicago Large Telescope failed
1971 Apr 5			5977.8 1143 x 204316 x 30.0
1971 Apr 7	1600	X,Y to 26m; X ant stuck
1971 Apr 15	1321	Y antennae to 36.5m
1971 Apr 19	1415	Y antennae to 45.7m
1971 Apr 26			5957.9 1842 x 203132 x 31.6
1971 May 10			5966.3 2390 x 202788 x 31.4
1971 Oct 14		GSFC plasma experiment activated
1971 Nov 17		End of GSFC plasma experiment ops
1972 Mar			10000 x
1973 Mar			12000 x
1974 Mar			4000 x
1974 Oct 2		Reentered