Bangalore: The Indian Space Research Organisation (Isro) said it has completed trials of a home-grown cryogenic engine to power rockets that can launch heavier communication satellites into space and could bring down costs of space transport.

Isro chairman G. Madhavan Nair (left) and Roskosmos ­director A. Perminov signing a lunar mission agreement recently

Cryogenic engine technology was the missing link in the Indian space agency’s expertise in launching conventional rockets, mastered by agencies such as the National Aeronautics and Space Administration (Nasa) and the European Space Agency.

“By mastering this (technology), India will be able to build rockets of any size," said B.N. Raghunandan, chairman of the aerospace engineering department at the Indian Institute of Science in ­Bangalore.

Heavier rockets such as India’s Geosynchronous Satellite Launch Vehicle, or GSLV, have three stages powered by engines that consume different types of fuel. The first stage has solid fuel, the second stage has a combination of liquid and solid fuel, and the final stage has liquid hydrogen and oxygen which power a cryogenic engine.

Cryogenic engines are “one- and-a-half times as energetic" as a liquid and solid fuel engine used in the second stage of the rocket, said Raghunandan.

Hindustan Aeronautics Ltd, India’s state-run aircraft maker, Godrej and Boyce Ltd, which makes the Vikas engines for Isro’s rockets, and MTAR Technologies Pvt. Ltd, a Hyderabad company that has investments from private equity firm Blackstone Group, have worked with Isro to design and build the home-grown engine in 10 years.

Since 2001, Isro has launched satellites on five GSLV rockets, including the one that crashed in the Bay of Bengal in July 2006, using cryogenic engines imported from Russia. GSLV rockets can now launch satellites weighing 2 tonnes into the geo-transfer orbit, or GTO, 36,000km above the earth. Communication satellites are placed at GTO, locking it with the rotation of earth, to ensure signals are transmitted to a location constantly.

India offers satellite launch services for global customers at three-fourths the cost of global space launch companies such as Arianespace and International Launch Services. “More than the cost, we are now self-reliant. It will also help us to market our launch services to global customers," said Isro chairman G. Madhavan Nair.

Isro plans to use the indigenous cryogenic stage to launch its next GSLV by mid-2008. The development of the cryogenic engine will also help it build a heavier rocket GSLV Mk-III to carry satellite of close to 4.5 tonnes by 2009.

Isro had announced on Tuesday that it will launch its second unmanned lunar mission, Chandrayaan-2, on a GSLV rocket in 2011-12, in partnership with Russian space agency Roskosmos.