INSAT-3B, launched on March 22, 2000 by Ariane Vehicle, has two solar arrays, one on the south and the other on the north side, each with an area of 11.5 sq m and generate a total power of about 1.7 kW. In today's operations, deployment of the solar array on the south side of the satellite was first carried out at 9:29 am IST.

This was followed by deployment of the antenna reflector on the west side at 12 noon IST. The solar panel on the north side was deployed at 02.02 pm IST. The deployment of the east side antenna was completed at 02:40 pm IST.

With the deployment of all the appendages on board in a flawless manner, a major milestone towards operationalising INSAT-3B has been crossed.

The third orbit raising manoeuvre on INSAT-3B had been successfully carried out yesterday March 26, 2000 at 11:54 am by firing the 440 Newton Liquid Apogee Motor (LAM) for 3 minutes and 9 seconds placing the spacecraft in a very near circular geosynchronous orbit.

The inclination of the orbits has been reduced to 0.1 degree and the orbital period is 23.75 hours. It is located at 68 degree east longitude and moving at the rate of 2.5 degree per day towards its final orbital loaction.

The solar array and the deployment mechanisms of INSAT-3B were developed by the ISRO Satellite Centre (ISAC) at Bangalore and the solar array drive mechanisms and Power Transfer Assembly were developed by ISRO Inertial Systems Unit, Thiruvananthapuram.

The deployments which are critical and intricate one-shot operations have to happen in the harsh space environment of vacuum, extremes of temperature and no gravity. The CFRP (Carbon Fibre Reinforced Plas-tic) C-band antennas for the communication payload were fabricated by Vikram Sarabhai Space Centre, (VSSC) Thiruvananthapuram. The pyro devices used in the mechanisms were also developed by VSSC.

The Liquid Apogee Motor (LAM), which was successfully fired in three phases to take the INSAT-3B from the Geosynchronous Transfer Orbit (GTO), into which it was injected by Ariane to the Geosynchronous Orbit (GO), was designed and developed by the Liquid Propul-sion Systems Centre, Thiruvananthapuram.

For the first time, an indigenously developed titanium propellant tank, with special propellant management device that ensures bubble-free propellant supply under zero-G environment, has been employed. The motor has performed to specifications.

All the systems on board the satellite are working satisfactorily. The satellite will be configured in the 3-axis stabilisation mode tomorrow March 28, 2000. Initial switch-on and testing of communications payload will be taken up in a phased manner over the next ten days.