INDIA will launch a recoverable satellite by the end of 2004 or in 2005 using a Polar Satellite Launch Vehicle (PSLV). The satellite, weighing about 450 kg, will splash into the sea, from where it will be recovered. It will carry payloads for conducting experiments such as growing crystals and developing pharmaceutical products in the micro-gravity ambience of space. The mission is called the Space Recovery Experiment (SRE). Apart from the satellite, the PSLV will carry CARTOSAT-2, an advanced satellite for cartographic purposes.
The critical technology to be mastered in the SRE mission is re-entry. The satellite should be coated with composites to prevent it from becoming cinders when it re-enters the earth's atmosphere at an extremely high velocity. It will be the Indian Space Research Organisation's (ISRO) first experiment with the re-entry technology, and will also be the first step in the ISRO's ambitious plan to build a space transportation system, which will be a kind of space shuttle.
Dr. B.N. Suresh, Director, Vikram Sarabhai Space Centre, Thiruvananthapuram, said: "Almost all the designs (for the SRE) have been completed. There are no technical uncertainties." Reportedly, some tests had been conducted on `dropping' the satellite, that is, the splashdown in the sea.
Steady progress is being made in the GSLV-Mark III project. The vehicle, which will have a height of 42.4 metres and a weight of 630 tonnes, can put a four-tonne satellite at a height of 36,000 km. According to S. Ramakrishnan, Project Director, GSLV-Mark III, its design review is nearing completion. Hardware fabrication has been initiated. Ground tests of the engines will start in 2006.
The Union government has approved the Chandrayan-1 mission, which will put a 525-kg satellite in an orbit 100 km from the moon. Again, it is the PSLV, ISRO's trusted workhorse, that will take this satellite to the moon. The PSLV had deployed in September 2002 a weather satellite called METSAT (later renamed Kalpana-1) in a geo-synchronous transfer orbit (GTO) at a height of 36,000 km above the earth. But the lunar mission requires that the PSLV to take the satellite over a distance 3.84 lakh km. So a modified and more rugged version of the PSLV will be built. It will initially put the satellite in GTO at 36,000 km above the earth. The satellite will then be manoeuvred into its final lunar orbit, using its own propulsion system. The satellite, or orbiter, will have cameras on board, which will beam back pictures of the moon's terrain, including its craters. It will throw light on the physical and chemical characteristics of the moon. This orbiter will also provide information about the mineral deposits.
A host of new challenging technologies have to be developed for the moon mission, including the setting up of a tracking and command network to keep a tab on the satellite and send commands to it, developing new imaging systems (cameras) to look at the lunar surface, and so on. Project teams have already started working on these. Sending a satellite to the moon using the PSLV will cost about Rs.380 crores.
This mission will provide ISRO scientists with the unique opportunity to conduct frontier scientific research. "Chandrayan-1 is expected to be the forerunner of more ambitious planetary missions in the years to come, including landing robots on the moon and visits by Indian spacecraft to other planets in the solar system," says an ISRO press release.
The PSLV will put in orbit in 2005 an Italian scientific satellite to study sudden bursts of gamma rays in space, according to Lanfranco Zucconi, managing director of the company Carlo Gavazzi Space SpA. This satellite will weigh about 500 kg.
ISRO is wary of revealing the identity of its potential customers, who will use the PSLV for orbiting satellites. The United States had pressured Taiwan to cancel an agreement that the latter had entered into with ISRO for putting a satellite in orbit.