Sirio 1

 1977-080A

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Sirio 1 tested Ku-band propagation, TV broadcasting and interactive video conferencing. NASA launched the satellite and controlled it for a 45 day test period after which control was from Fucino. After a successful 6 year test program at 15W, it was relocated to the Indian Ocean for experiments with the People's Republic of China. In 1985 the satellite was moved to 75.1E for VHF propagation experiments. The hydrazine ran out during this move and pressurization gas was used instead; 75.1E is a stable point where EW stationkeeping is not required. After that date it was operated intermittently. On 1989 Sep 28 it was switched off after performing end-of-life maneuvers.

Sirio was built by CIA SpA (Compagnia Industriale Aerospaziale, Roma), a consortium probably of Aeritalia and Selenia. They operated the spacecraft for 45 days, and then it was transferred to Telespazio from control from Fucino and Lario.

Launch mass was 398 kg. Size 1.44 dia 0.95 high cylinder bus, 2.0m high overall including antenna and ABM nozzle (1.5m without nozzle). The SNIA ABM is ellipsoid-cylinder 1.27 long 0.49 dia.

The apogee motor fuel was 178 kg with 500 kNs impulse. It gave a dV of 1.634 km/s in a 35 s burn using up 177kg of fuel and with an SI of 284s. On orbit the satellite was 220 kg (190 kg dry) and spun at 90 rpm. 30 kg of hydrazine.

Post 1999 TLEs for SIRIO appear to be cross-tagged with Ekran 9.

Sirio was moved to the eastern GEO stable point 75E in 1985; it librates between 74.4E and 75.9E.

Sirio dry	168 kg
ABM dry	22 kg
ABM prop	178 kg
Hydrazine	30 kg
Total	398 kg

Thanks to Ted Molczan:

Objects mistagged as Sirio 1
Date	Time	Event	Orbit
1979 Oct 23		08366 GOES-1? [Mistag]	1437.71 35612 x 36023 x 1.3 GEO 116W+0.4W
1985 Mar 30-1999		Insat 1A	1435.005 35694 x 35836 x 4.08
1999-2002		ISON UI.41 (C00101)

Sirio 1
Date	Time	Event	Orbit
1977 Aug 25	2349	Launch by Delta 2313	CC LC17
		T+0:38 SRM 1-3 off
		T+1:10 SRM 1-3 sep
		T+3:48 MECO
		T+3:56 Stage 1 sep
		T+4:06 SES-1
		T+4:55 Fairing sep
	2358	T+8:54 SECO-1 180? x 180? x 28.5
		13 min coast
1977 Aug 26	0010	T+21:55 SES-2
	0011	T+22:08 SECO-2	180? x 2081?
	0012	T+23:07 spinup
	0012	T+23:09 Stage 2 sep
	0012	T+23:51 Star 37D burn
	0013	T+24:35 TECO	230 x 37670 x 23.0
	0014	T+25:47 Stage 3 sep
	0029?	Depletion	872 x 2081 x 27.1
	0500?	Apo 1
	1700?	Apo 2
1977 Aug 27	0400?	Apo 3
	1500?	Apo 4
1977 Aug 27	1457	Sirio AKM burn
1977 Sep 8		On station	GEO 15W
1977 Sep 15		Final trim, 24 kg hydrazine left
1977 Sep 29		Fucino tests
1977 Sep 29	0000	To SIOCC Telespazio/Fucino
1977 Dec 1	1120	EW trim burn 15.6W
1978 Mar 30	0745	NS trim burn
1978 May 2	1911	EW trim burn	GEO 15.6W
1978 Jul 21			GEO 14.6W
1978 Oct 31	1612	NS trim burn, 18.5 kg left	GEO 15.0W
1978 Dec 12	1240	EW trim
1979 Apr			GEO 15W
1979 May 4		NS and EW trim
1979 Oct 30		NS and EW trim
1980 Dec			GEO 15.2W
1981 Nov 5		First archival TLE	1436.21 35776 x 35801 x 0.1 GEO 24.9W
1982 Oct 30			1436.11 35767 x 35806 x 0.1 GEO 24.4W
1983 Jan 9			1436.09 35772 x 35800 x 0.0 GEO 24.5W
1983 Mar			GEO 25W
1983 Mar 24		Out of GEO
1983 Aug		Arrive 65E for PRC experiments	GEO 65E
1983 Aug 30			1436.34 35774 x 35808 x 0.5 GEO 65.3E
1984 Mar			GEO 64E
1985 Jan			GEO 65E
1985 Jan 30			1436.01 35769 x 35800 x 1.7 GEO 65.2E
1985 Feb 28		mv out	35760 x 35793 x 1.8
1985 Mar 30			1435.53 35758 x 35792 x 1.9 GEO 70.8E+0.13E
1985 Apr		AOCS problem
1985 Apr 9		Stop at 73.3E
1985 Apr 10		Fucino ground stn dismantled (to San Marco)
1985 Apr 11		Stop burns 1-2
1985 Apr 17		Stop burn 3-12
1985 Sep		mv in at 75.1E
1987 May 30		[Mistag]	1435.37 35733 x 35810 x 4.0 GEO 36.7E+0.2E
1987		Orbital trim
1989		Attitude manuever tests
1989 Jul 12		[Mistag]	1436.41 35726 x 35858 x 5.9 GEO 29.1E
1989 Sep 28		end of ops	GEO 75E
1990 Mar 25		[Mistag]	1434.75 35704 x 35816 x 6.6 GEO +0.33E
1999 Apr 27		[Mistag]	1437.30 35721 x 35899 x 12.5 GEO 56.9E+0.3W