Indias Dream Launch PSLV C7

The Indian Space Research Organisation (ISRO) added yet another achievement to its list by the successful launch of the PSLV-C7 from the Satish Dhawan Space Centre at Sriharikota on January 10, 2007. The four-stage, 44 metre tall Polar Satellite Launch Vehicle (PSLV-C7) which weighs 295 tonnes took off on the dot at 9.23 a.m. from its beachside launch pad and injected four satellites into precise orbit. This is the PSLV`s ninth consecutive successful launch. Of the four satellites two satellites belong to India and two are from abroad. The satellites from abroad are LAPAN-TUBSAT, a joint venture of Indonesia and the Technical University of Berlin and the PEHUENSAT-1 of Argentina. Dr. B.N.Suresh, Director, Vikram Sarabhai Space Centre (VSSC), Thiruvananthapuram, which built PSLV-C7, said, “Four satellites being injected into orbit with the same vehicle is a unique experience for us”.

This multi-mission launch is going to be a technological challenge for ISRO as it attempts to deorbit one of the satellites and bring it back to earth on January 22, 2007. The satellite called the Space Capsule Recovery Experiment (SRE) will stay in orbit for 11 days and thereafter fall into the Bay of Bengal from where it will be recovered. This challenging job will be headed by Project Director, Mr. A.Subramoniam. “Right now, I feel that my job has just started. I am looking forward to January 22, 2007 morning when the SRE will be recovered”, Mr. Subramoniam said.

ISRO`s Cartosat-2 is for mapping purposes and its SRE will be a forerunner to the ISRO mastering the re-entry, recoverable and re-usable launch vehicle technologies. During its stay in orbit the two payloads on board the SRE will help conduct experiments in micro-gravity.

The 555 kilogram SRE is coated with thermal tiles to prevent it from burning up when it re-enters the earth’s atmosphere. After it re-enters the atmosphere, about 5 km above the Bay of Bengal, three parachutes in the SRE will open up one after another. First, the pilot chute will pull out the drogue chute, which will deploy, and then the main chute will deploy. The main chute will slow down the descent of the SRE and it will ultimately splash down into the Bay of Bengal, about 140 km east of Sriharikota island. A floatation system will keep it afloat and dye markers will make it visible. The Coast Guard will recover it.

The entire process involves a lot of precision as the SRE should be de-orbited in the right direction and should be given the right incremental velocity. It should re-enter the atmosphere without burning up. According to the ISRO Chairman, Mr. G. Madhavan Nair, “There are a lot of technological challenges in bringing back an orbiting satellite because we are doing it for the first time”.

Besides the technology of bringing to the SRE back to earth in a sequential manner, the PSLV-C7 has also used Dual Launch Adopter (DLA), a device to launch four satellites for the first time. It also used for the first time a video-imaging system on board to take pictures of the separation of the first three satellites from the fourth stage of the rocket.

According to Mr. M. Krishnaswamy, Project Director, Cartosat-2, the satellite`s images could be used in town and rural planning as well as in road and drainage alignment. It could also be used in studying the passage of communication lines. The PSLV-C7 has been built at a cost of Rs.80 crore. The Cartosat-2 cost Rs.180 crore and the SRE Rs.30 crore.

After the setback in July 2006 when Geosynchronous Space Launch Vehicle (GSLV) failed, the success of PSLV is a great morale booster. However, it goes without saying that India has a long way to go before it finds itself a place in the world space launch market. The Missile Technology Control Regime embargo on India’s space and military rocket programmes debars an Indian rocket to launch any American satellite, or one with US components. According to an official dealing with the issue a joint working group would hold a meeting in Washington in February, 2007 to get this embargo lifted under the Next Steps in Strategic Partnership negotiations. Moreover, countries like Russia, the United States, the European Union or Japan are far more developed in space launch vehicle technology. We compare well with the Chinese Long March CZ4B series when it comes to hoisting satellites to a Low Earth Orbit to about 2,000 kms. But so far as geosynchronous orbits of 36,000 kms used for communication satellites for beaming.

PSLV Chronology
Launch Vehicle	Date of Launch
PSLV-D1	Sept. 20, 1993
PSLV-D2	Oct. 15, 1994
PSLV-D3	Mar. 21, 1996
PSLV-C1	Sept. 29, 1997
PSLV-C2	May 26, 1999
PSLV-C3	Oct. 22, 2001
PSLV-C4	Sept. 12, 2002
PSLV-C5	Oct. 17, 2003
PSLV-C6	May 5, 2005
PSLV-C7	Jan. 10, 2007

TV programmes or relaying telephone calls are concerned we are far behind. The success of PSLV cannot fill the void created by the failure of GSLV.