Explorer 55

 1975-107A

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Atmosphere Explorer E (Explorer 55) was launched on 1975 Nov 20 at 0206 by a Delta 2910 from Cape Canaveral into a 156 x 2983 km x 19.7 deg orbit. It complemented the AE-C mission by studying the equatorial thermosphere. During 1976 the perigee was varied between 130 and 180 km; the apogee was allowed to decay. On Nov 20 the burn was made to start the second phase of the mission in a 390 x 390 km circular orbit, which was reboosted whenever it decayed to 250 km altitude. AE-E reentered over the Carribean on 1981 Jun 10 at 1357.

Explorer 55
Date	Time	Event	Orbit
1975 Nov 20	0206:48	Launch by Delta DSV-3P-11D
		T+0:38 Castor II 1-6 burnout
		T+0:39 Castor II 7-9 on
		T+1:17 SRM 7-9 out
		T+1:27 SRM 1-9 sep
	0210:31	T+3:43 MECO
	0210:39?	T+3:56 Stage 1 sep
	0210:44	T+3:56 SES-1 3:43
		T+4:37 Fairing sep
	0214:27	T+7:49 SECO-1	157 x 160? x 28.5?
	0230:38	T+23:50 SES-2 82s
	0232:00	T+25:12 SECO-2
		Spinup
	0240:08?	T+33:20s Stage 2 sep
1975 Nov 25			117.29 156 x 2983 x 19.7
1976 Sep 4			98.54 141 x 1236 x 19.7
1976 Oct 2			93.86 140 x 786 x 19.7
1976 Oct 22			90.32 150 x 430 x 19.6
1976 Nov 13			89.18 188 x 279 x 19.7
1976 Nov 16			90.29 256 x 320 x 19.6
1976 Nov 23			89.82 264 x 267 x 19.7
1977 Feb 28			89.4 241 x 244 x 19.6
1977 Dec 31			90.0 275 x 275 x 19.6
1978 Dec 31			93.9 461 x 466 x 19.6
1979 Jun 30			93.6 447 x 450 x 19.6
1979 Oct 31			93.6 447 x 449 x 19.6
1981 Feb 28			91.9 367 x 368 x 19.6
1981 Apr 30			90.7 306 x 313 x 19.6
1981 Jun 10	1357	Reentered over Caribbean

Payload:

• CEP Cylindrical Electrostatic Probe (GSFC/Brace)

• MESA Accelerometer (AFCRL/Champion)

• PES Photoelectric Spectrometer (APL/Doering)

• RPA Retarding Potential Analyser (UTD/Hanson)

• BUV Backscatter UV spectrometer (GSFC/Heath)

• ESUM Solar UV Monitor (GSFC/Heath), 40-1100A solar flux

• EUVS Extreme Solar UV Spectrometer (AFCRL/Hinteregger), 140-1850A

• OSS Open Source Spectrometer (UMn/Nier)

• NACE Neutral Atmosphere Composition Experiment (GSFC/UM/Pelz)

• NATE Neutral Atmosphere Temperature Experiment (GSFC/UM/Spencer)

• BIMS Bennett Ion Mass Spectrometer (GSFC/Brinton)

• VAE Visible Airglow Experiment (UM/Hays)

• PSB Capacitance Manometer

• CCIG Cold Cathode Ion Gauge