GSAT-1

 2001-015A

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The GSAT-1 experimental comsat is a test payload for ISRO's GSLV rocket, which is derived from PSLV. The GSLV stage 3 has a LOX/LH2 RD-56M engine. Launch was from SHAR in 2001.

GSAT was to have demoed digital audio and compressed TV from 48E; The satellite is similar to Insat-2, with a single solar array and a counterweight solar sail boom.

Control from Hassan. Mass is 1540 kg. The GSLV flight was a little underpowered, with the 12KRB stage's Isp only 454s instead of the predicted 461s.

The satellite fuel was depleted reaching near-GEO due to problems with the propulsion system. During 2001, GSAT-1 was operated by Hassan when the satellite was within view. It was operated until May 2002.

The GSLV was made up of 4 L40H boosters, the S139 stage, the L37.5 GS2 stage, and the C12 GS3 cryo stage.

GSAT-1
Date	Time	Event	Orbit
2001 Mar 28	1017	GSLV-D1 SOM ignition	SHAR
		SOM abort on pad
2001 Apr 18	1013	T-4s PSOM ignite
	1013:01	Launch
		T+1:40 St 1 burnout 2.63 km/s
		T+2:27 St 2 MES
		T+2:29 GS1 sep
		T+2:29? PSOM cutoff at 75 km
		T+2:35 Interstage sep at 75 km 2.9km/s
		T+4:40 Fairing sep 115 km 3.9 km/s
		T+5:07 St 2 MECO 126 km, 5.18 km/s
		T+5:14 St 2 sep	-4541 x 127 x 19?
		T+5:14 St 3 MES 11:33
		T+16:47? St 3 MECO 195 km, 10.17 km/s
	1030:20	T+17:19 St 3 sep
		St 3 passivation
2001 Apr 18	1508	Apogee-1	557.93 166 x 31977 x 19.3
	1947	Perigee-2	182 x 32140 x 19.28 (ISRO)
2001 Apr 19	0023	LAM-1 at apogee 19:37 166 kg	3000 x 32000 x 19.3
2001 Apr 19	1543	LAM-2 4min 75m/s	3000 x 35880 x 13.3 (ISRO)
2001 Apr 20			724.86 4864 x 35838 x 11.5
2001 Apr 20	2020	LAM-3 600m/s	11900 x 35830 x 5.5
2001 Apr 23		LAM-4
2001 Apr 25			1384.12 33800 x 35725 x 1.0
2001 Apr 26			1384.54 33804 x 35738 x 1.0