IRS-1D

 1997-057A

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IRS-1D is a duplicate of IRS-1C, with a LISS-3 sensor and a wide field sensor. It was launched by PSLV but the fourth stage shut down early with a loss of pressure, and the satellite was left in an elliptical orbit (0.13 km/s too slow). On-board propulsion was used to reach the intended orbit. Mass is 1200 kg.

The first operational flight of PSLV was upgraded to carry a 1200 kg payload. The new S-139 first stage motor replaced the S-125. The SRB firing order was changed; previously 4 SRBs ignited at T=0 and 2 later, now 2 fire at T=0 and 4 later. 

IRS-1D
Date	Time	Event	Orbit
1997 Sep 29	0447	Launch by PSLV-C1
		T+00:30 PSOM 5-6 ignite
		T+00:54 PSOM 1-4 cutoff
		T+01:18 PSOM 1-4 sep
		T+01:19 PSOM 5-6 cutoff
		T+01:30 PSOM 5-6 sep
	0449	T+01:52? PS-1 cutoff and sep
	0449	T+01:52? PS-2 burn
	0449	T+2:36? Fairing sep
	0451	T+4:41? Stage 2 sep, PS-3 burn
	0452	T+5:33? PS-3 cutoff
	0455?	T+8:23? PS-3 sep
	0456?	T+9:45? PS-4 burn
	0500?	PS-4 premature MECO
		PS-4 sep
1997 Sep 29			95.96 308 x 822 x 98.64
1997 Oct 1			96.18 328 x 823 x 98.6
1997 Oct 6			98.53 555 x 822 x 98.6
1997 Oct 10			100.38 727 x 826 x 98.6
1997 Oct 18			100.50 739 x 826 x 98.6