Rocket technology With the success of the recent GSLV-D5 flight, Isro is now looking to make the GSLV a reliable launch vehicle like the PSLV, writes Prashanth G N

The successful flight of GSLV-D5 launch vehicle on January 5 from Satish Dhawan Space Centre SHAR, Sriharikota, has positive implications for India’s rocket development capabilities. The flight signals that India is on its way to become a leading player in heavy rocket technology, capable of placing in orbit heavy satellites ranging from 2,000 kg to 5,000 kg. Another strong implication is that India is now capable of building an indigenous cryogenic (study of low temperatures) stage and engine which would be successful in flight.

The Indian cryogenic stage worked flawlessly in the January 5, 2014 flight, launching a communication satellite — GSAT-14, very precisely to its intended Geosynchronous Transfer Orbit. So far, Isro had been flying the Russian cryogenic stage, but with the success of its own version, dependence on Russia or any Western space power may begin to come down. Isro had bought seven engines from Russia and has used up six of them.

Traditionally, western space agencies, including US and Europe, denied cryogenic technology to Isro claiming that Isro would use the same for military purposes. So, as sanctions against India continued for years, India set up a team in the 1990’s to develop its own cryogenic stage. It has taken 20 years for India to develop cryogenic technology after preliminary work began in the 1990’s. But this is not a cause for concern as the average time taken by American and European scientists to develop cryogenic technology was around 10-15 years. Now, only six countries in the world have developed indigenous cryogenic technology, and India is one among them.

What the success of the cryogenic stage signals is that India can now put heavy satellites into space on its own. Isro is heading to a time when it wouldn’t have to go to American, European and Russian rockets to launch heavy satellites. Some initial work on the cryogenic technology had begun in the 1980’s before a formal team was set up in 1994. In 1988, a prototype engine had been developed, but it blew up on the test bed.

Again in 2000, another engine that was developed, blew up. However, in 2002, Isro was successful in developing the engine, which was qualified in 2003. After integrating it with the GSLV over four years, Isro finally decided to test the engine in flight. A flight with the cryogenic engine failed in 2010 and after that Isro conducted intense studies to make the engine operational. In 2014, the Indian cryogenic engine was deployed a second time, and this time it was a tremendous success.

The success of cryogenic engine is crucial because it can help place satellites in distant orbits — as far as 35,000 km above earth, which is known as the geo-stationary orbit. Only the GSLV, a more powerful rocket than the PSLV, can do this job.

The January 5, 2014 flight is also crucial in that it opens up possibility to undertake moon missions. While India’s first moon mission was powered by the PSLV in 2008, the second moon mission will require a powerful rocket. An advanced version of the PSLV may be used, while the option now to use the GSLV is available.

Yet another implication of the GSLV success is that it has opened the doors for the human space flight programme planned sometime around 2017-18. To send a man to space would require tremendous power and thrust, which the GSLV alone in its Mark-III version can undertake. Post this flight, the human space programme seems to be getting real. The crew would be injected into space by the GSLV.

Troubled past

The GSLV has had a troubled past with as many as three failures in flight. This eighth test flight though was a success, and will help in developing advanced versions of the GSLV, particularly the GSLV Mark-III, which is under development. GSLV Mark-III will help in launching satellites between 4,500 and 5,000 kg. The Mark-III vehicle envisages multi-mission launch capability for GTO, LEO, Polar and intermediate circular orbits. Isro will undertake two more flights of the GSLV to declare it operational.

Isro chairman K Radhakrishnan has said it is now time for the GSLV to become a reliable launch vehicle like the PSLV. Once it is declared reliable, Isro can begin to launch heavy satellites of foreign countries too, and thereby get a share in the world market for heavy satellite launches. Once GSLV Mark-I and Mark-II have been declared reliable, the doors would be open for GSLV Mark-III to get the same certification.

The first flight of GSLV took place from SHAR on April 18, 2001 by launching 1,540 kg GSAT-1 (successful). It was followed by six more launches, GSLV-D2 on May 8, 2003 (GSAT-2 1,825 kg — successful)), GSLV-F01 on September 20, 2004 (EDUSAT 1,950 kg — successful)), GSLV-F02 on July 10, 2006 (unsuccessful), GSLV-F04 on September 2, 2007 (INSAT-4CR 2,130 kg — successful), GSLV-D3 on April 15, 2010 (unsuccessful), GSLV-F06 on December 25, 2010 (unsuccessful) and GSLV-D5 on January 05, 2014 (GSAT-14 1,982 kg — successful).