The Indian Space Research Organisation (ISRO) successfully tested an indigenous cryogenic engine which will allow launch vehicles to carry satellites of up to four tonnes. Congratulating the scientists on the successful testing, Prime Minister Mr Narendra Modi said on Twitter, “The engine tested today will enable us to put satellites of up to 4 tons in geostationary orbit. A proud accomplishment.” Although the Geosynchronous Satellite Launch Vehicle (GSLV Mark III) successfully launched an unmanned capsule that could be used for manned missions in December, it had a passive cryogenic stage. While GSLV Mark III is India’s largest launch vehicle, carrying up to four-tonne vehicles will only be possible with a cryogenic engine with the capacity. India has till now been dependent on foreign launch vehicles to send heavier satellites to the required orbits. “There was a special test set up in Mahendragiri to see if the engine developed the exact thrust required to launch payloads of that weight. It succeeded,” an ISRO spokesperson told Mint on the phone. “Now we’ll have to prove if this engine can be used in a launch vehicle,” the spokesperson added. Mahendragiri in Tamil Nadu is home to the ISRO Propulsion Complex, where cryogenic engines are tested. India has been on a long arduous journey to develop an operational indigenous cryogenic engine which began around 30 years ago. The first success came in January last year, when India successfully launched GSLV-D5, marking the first successful launch of a vehicle with an indigenous cryogenic engine. But India at present can only launch satellites of up to two tonnes.