The Indian Space research Organisation (ISRO) is slated to test fly this month a small model of what is called a ‘scramjet’ engine that could one day help to put satellites and other systems to space.

Scientists are quietly keeping their fingers crossed about it. This half-metre, 45-kg model could later grow to power a future dream Indian rocket of two stages (compared to three and four stages at present); a rocket that launches satellites and systems super efficiently at much lower costs than now.

Reliable

The scramjet bid is a move towards faster, cheaper, better rockets; if it works, an eventual launch vehicle using a scramjet engine can be very reliable compared to conventional rocket systems that use liquid or cryogenic systems, said a propulsion scientist who did not want to be named.

In March 2010, the ISRO tested a passive scramjet engine module on a customised sounding (experimental) rocket, named Advanced Technology Vehicle (ATV-D01).

The specialty of the ‘scramjet’ engine is that it ‘inhales’ air from the atmosphere and uses its oxygen to burn. In turn it pushes the vehicle and helps to release the satellite in it to space. Regular launchers now carry liquid oxygen or an oxidiser to fire the engine.

In the upcoming experiment — or demonstration — of the air breathing technology, a small model of a scramjet engine is flown on the experimental ATV to a certain distance in space and ignited. The ISRO expects to sustain the engine for five seconds this time.

K.Sivan, Director of Vikram Sarabhai Space Centre (VSSC) which is the lead centre for launcher activities, had earlier told The Hindu that sustaining the engine burn for even this tiny duration is extremely challenging.