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India's GSLV reaches orbit, but can it be a contender?
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| 20 April 2001 |
By Philip Clark
The long-delayed first launch of India's Geosynchronous Satellite Launch Vehicle (GSLV) came on 18 April from Sriharikota. The flight, designated GSLV-D1, began at 10.13 GMT and placed the 1540kg GSAT 1 payload into a geosynchronous transfer orbit (GTO). The satellite will use its own propulsion system to reach a geosynchronous (24-hour) orbit.
Data issued by USSPACECOM indicates that the orbit is slightly lower than a true GTO, having the following parameters: inclination 19.3 degrees, orbital period 557.6 minutes, perigee 168km and apogee 31,961km. This orbit has an apogee that is ~4,000km lower than a true GTO; it is unclear whether this is intentional or whether it indicates a slightly lower-than-nominal performance of the launch vehicle.
The GSLV has been delayed because of technical problems and international space politics. It is a three-stage vehicle, with the first stage supplemented by four liquid-propellant strap-on boosters. The first two stages are modifications of those used on the previously flown Polar Satellite Launch Vehicle (PSLV), but in order to attain the required payload capability the Indian Space Research Organisation (ISRO) realised that the third stage would need the performance that could only be delivered using a liquid hydrogen/liquid oxygen motor - a technology the Indians lacked.
Engines waiting for a mission
ISRO officials first approached Japan, expressing an interest in purchasing the Japanese LE-5 motor, but nothing came of this. They were offered engines by the United States and Europe, but the prices were too high. Consideration was being given for the development of an Indian liquid hydrogen/oxygen engine when an offer came from the Soviet Union. In 1988 an agreement was signed with Glavcosmos and subsequently an engine variously designated KVD-1 and 11D56 was offered to ISRO. The KVD-1 was not a new engine, but at the time it was relatively unknown outside the Soviet Union. During the 1970s the Soviets planned a series of manned lunar missions designated L-3M that intended to land three men on the Moon. The mission was to use a large lunar lander capable of supporting a lunar stay of a month, and the engine developed by the Isayev bureau (now Khimmash) for this lander was the KVD-1. Although the L-3M never came close to flight status, the KVD-1 was thoroughly tested on the ground and declared ready for operational use. The engines and their technology were then mothballed.
A question of technology transfer
The deal signed by ISRO and the Russians called for flight-ready engines to be sold to ISRO as well as the technology to allow ISRO to develop and manufacture its own liquid oxygen/hydrogen engines. The USA objected strongly to the technology transfer aspect of the agreement, and in 1992 President Bush announced that, if the deal went ahead, sanctions would be applied to both ISRO and the Russians. The Indians complained, pointing out that the development of such a rocket engine had no military application; the propellants are everything you do not want for a missile programme.
In 1993 the arrival of President Clinton brought a compromise: the sanctions would be eased and eventually removed if the agreement between ISRO and the Russians were modified to allow only the sale of flight-ready, assembled engines without any technology transfer. The Russians reluctantly agreed to this in October that year, pacifying the United States but annoying the Indians.
The final agreement called for the supply of seven KVD-1 engines to ISRO for use on the GSLV (at a much lower price than the original agreement), together with two boilerplate models that could be used for integration tests. The first boilerplate was delivered in 1997 and the first 'real' engine arrived in India in September 1998.
Later than planned, a new kid on the block
As a result of the politics outlined above, the maiden flight of the GSLV has come about six years later than originally planned. The supply of seven KVD-1 engines from Russia has meant that ISRO has had time to develop its own liquid oxygen/hydrogen engine. The first prototype - with a thrust of one tonne compared with the required GSLV third stage thrust of 7.5 tonnes - was tested-fired in 1997.
The introduction of the GSLV means that India no longer has to rely upon foreign launchers to place communications and remote sensing satellites into geosynchronous orbits. However, whether the GSLV will ever become a viable commercial launch vehicle is open to question; there are already sufficient launch vehicles available for such work without a newcomer entering the marketplace.