Isis 1

 1969-009A

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The followon to Alouette was Isis, the International Satellite for Ionospheric Studies. Isis 1 was built by RCA Victor Ltd. (Montreal). It was used by both CRC and NASA until 1979, and by CRC alone from 1979 to 1984. The project was the reponsibility of the CRDB (Canadian Defense Research Board) and the DOC (Canadian Dept of Communications). The spinning satellite deployed two large dipole antennae. During the early years, command and control was from GSFC. After 1979 it was transferred to CRC and in 1984 the satellite was donated to Japan's ISAS which used it till 1990.

As well as the swept frequency sounder like the Alouette satellites, Isis 1 carried a fixed frequency sounder like that on Explorer 20.

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Mass 236 kg (PK: 241 kg). Octagonal double cone size 1.27d 1.04h span 73m. Two debris objects separated from ISIS 1 in May 1993.

Isis 1
Date	Time	Event	Orbit
1969 Jan 30	0646	Launch by Delta E1 (Delta 65)	V SLC 2E
		T+0:42 SRM burnout
		T+1:10 Castor 1 SRM sep
		T+2:30 MECO
		T+2:34? St 1 sep
		T+2:36 SES 5:50
		T+2:42 Fairing sep
	0654	T+8:30 SECO
	0658	T+11:59 Spinup
	0658	T+12:02 St 2 sep
		T+12:02 Petal truss straps (2) separate
	0658	T+12:15 FW4D burn 31.0s
	0658	T+12:45 TECO
	0700	T+14:40 FW4D sep	128.4 578 x 3526 x 88.4
	0700	T+14:40 Extend antenna booms
1969 Feb 4		Operational
1979 Oct 1		NASA support ends, to CRC
1984 Mar		end of CRC support
1984 Mar		Data used by ISAS
1990 Jul		End of ISAS use

Payload:

• Dipole antenna, 18.7 m

• Dipole antenna, 73m

• VLF receiver (DRTE/Barrington)

• Cylindrical Electrostatic Probe (GSFC/Brace)

• Fixed Freq Sounder (Lockheed, DRTE/Nelms)

• Cosmic radio noise (DRTE/Hartz) 0.1-20 MHz

• Energetic particle detector (NRCC/McDiarmid)

• Spherical electrostatic analyser (AFGL/Sagalyn)

• Swept frequency sounder (DRTE/Nelms)

• Ion mass spectrometer (AFCRL/Narcisi)