March 13, 2007 

The first critical orbit-raising manoeuvre on INSAT-4B was successfully conducted at 5:35 am this morning (March 13, 2007) with the firing of the 440 Newton Liquid Apogee Motor (LAM) on board for 93 minutes by commanding the satellite from Master Control Facility (MCF) at Hassan in Karnataka. With this LAM operation, INSAT-4B perigee has been raised to 14,244 km. The apogee is at 35,752 km and the inclination of the orbit with respect to the equatorial plane has been reduced from 4.5 deg at the time of entering into orbit to 1.15 deg now. The present orbital period is 15 hours 21 minutes.

It may be recalled that INSAT-4B was successfully launched by Ariane 5 launch vehicle yesterday (March 12, 2007) from Kourou, French Guyana. The launch vehicle placed INSAT-4B in the intended Gesynchronous Transfer Orbit (GTO) with a perigee (closest point to the earth) of 250 km and apogee (farthest point to earth) of 35,886 km. MCF acquired the first signals at 4:02 am IST on March 12, 2007 and conducted initial phase operations on INSAT-4B. The satellite which had gone out of radio visibility of MCF at 2:04 pm yesterday, came within its radio visibility again at 1:00 am this morning. The satellite was oriented suitably before the start of LAM operations.