In his first address at the Physical Research Laboratory (PRL) as ISRO chairman, Dr. V Narayanan spoke about the importance of cryogenic propulsion systems in ISRO's achievements with satellites and launch vehicles.

During the 101st Amrut Vyakhyaan, Narayanan emphasized three world records set during the development of the cryogenic upper stage for the LVM Mark-III vehicle, a three-stage medium-lift launch vehicle.

The LVM Mark-III ROCKET is designed to launch communication satellites into geostationary orbit and is intended for crewed missions under the Indian Human Spaceflight Programme.

Narayanan highlighted that ISRO achieved a successful flight in just 28 months, surpassing the previous world record of 42 months. This was accomplished with only three engines: one for engine-level testing, one for stage-level testing, and one for high-altitude testing and flight, compared to the international average of 10.


Additionally, ISRO completed the rapid stage hot test for the C25 stage in just 34 days, which is an unmatched feat internationally. Narayanan also mentioned key achievements, such as the Gaganyaan Program, which involves developing human-rated propulsion systems and demonstrating crew escape systems, including a test vehicle demonstration with a liquid engine.

"For human landing on Moon, at ISRO we are conceiving a vehicle with a lift-off mass of approximately 20 tonnes, three times that of the LVM Mark-III, with three stages each containing 500-750 tons of propellant," said Narayanan.

ISRO is also advancing air-breathing propulsion technology to utilize atmospheric air as an oxidizer, which reduces the need to carry large amounts of oxidizer. This technology facilitates low-cost space transportation by eliminating the need to carry oxidizer for combustion, which makes use of atmospheric oxygen, and in turn, improves the payload fraction (the fraction of payload to the lift-off mass) ISRO is also pursuing rocket technologies that eliminate atmospheric contamination.

ISRO successfully conducted the second experimental flight for the demonstration of Air Breathing Propulsion Technology on July 22, 2024. During the test, propulsion systems were symmetrically mounted on either side of an RH-560 sounding rocket and launched from the Satish Dhawan Space Centre in Sriharikota at 7 am.

The flight test achieved satisfactory performance of the sounding rocket along with successful ignition of the Air Breathing propulsion systems. Nearly 110 parameters were monitored during the flight to assess its performance, and the flight data will be useful for the next phase of development of these propulsion systems. Prior to the mission, multiple ground tests were carried out at various ISRO centres.

Furthermore, ISRO is planning to develop high thrust engines of 300 tons, compared to the current maximum of 80 tonnes, to support crewed missions to Moon.

TOI Report