Sanjay Kumar writes: On 23 May 2016, ISRO successfully launched the first technology demonstrator of indigenously made Reusable Launch Vehicle (RLV), dubbed as India’s Space Shuttle from Sriharikota in Andhra Pradesh. The 6.5 metre-long scale model of the re-usable launch vehicle weighs about 1750 Kgs and was made at a cost of Rs. 95 crore. It was built at the Vikram Sarabhai Space Centre in Thiruvananthapuram by a team of 600 scientists over five years. Known as hypersonic flight experiment, it was about 770 seconds mission from lift off to splashdown. ISRO plans to test two more such prototypes before the final version which will be about six times larger at around 40 metres and will take off around 2030. The main rationale for developing a reusable system is to bring down the costs of satellite launch, and to increase the frequency of launches.
The spacecraft was launched atop a nine-ton rocket engine that has been designed to burn slowly to accommodate vertical lifting of a winged body space plane. After the launch, the booster rocket carried the RLV to an altitude of 56 Kms where the booster separated and the space shuttle flew further up to an altitude of 65 kilometres. RLV-TD then came back to Earth, hitting the atmosphere at Mach Five and ultimately splashing down in the Bay of Bengal at a designated spot about 450 km from the launch site.
In this mission, ISRO tested certain critical technologies such as autonomous navigation, guidance and control, reusable thermal-protection system, and re-entry mission management. The vehicle withstood the fiery re-entry which is one of the most critical stage, validating the re-usable thermal protection systems wrapped around it. The separation of the RLV from the booster rocket at an altitude of 56 km was smooth and all controls worked as specified. The hypersonic re-entry into the atmosphere and making a controlled autonomous landing at pre-designated area was commendable achievement by ISRO on its maiden test flight.
ISRO with RLV aims to achieve low cost, reliable and on-demand space access. Reusable launch systems will change the global scenario – the way world uses space for civilian, commercial and military purpose. The reduction in cost of spaceflight could be ten times. It will extend humanity’s footprint into the solar system and enable people to live and work in space.
No other country is currently operationally flying a winged spacecraft into space – the US retired its space shuttles in 2011 and the Russians flew theirs only once in 1989. Presently, Space X and Blue Origin two private companies are working towards making traditional rockets re-usable as opposed to developing winged vehicles that can make horizontal landings. India still going for winged space plane indicates larger technology development interests for LEO and near-space – which could be stepping stone for larger civilian, commercial and military use in future. Only time will tell how much reduction in cost ISRO would be able to accrue, depending upon degree of re-usability and cost to make RLV reusable. The winged space plane is indeed more challenging as larger surface area is susceptible to more thermal and atmospheric pressures and it will also need approximately 5 Km long runway to land.
On 21 Dec 2015; SpaceX launched a Falcon 9 rocket from Cape Canaveral into space. The rocket boosted 11 Orbcomm communications satellites into orbit before turning around and gracefully landing on the ground. In November 2015, Blue Origin another private spaceflight company founded by Amazon’s Jeff Bezos launched a rocket and then landed it vertically on the ground. On 22 Jan, 2016, Blue Origin re-used the earlier rocket booster to deploy an unmanned crew capsule at an altitude of 101 Km, which the company hopes will one day carry tourists into space. Thus Blue Origin has become the first company to actually reuse its vertical-lift rocket. Both SpaceX and Blue Origin are using thrusters to bring down rocket boosters to make controlled and smooth landing.
The innovation and ingenuity of this new generation of space-launch vehicles is going to change the way mankind uses space. The lower cost and increased efficiency of reusable rockets will have far-reaching impacts in many different fields. The reusable technology facilitates more space missions at reduced cost. On demand access to space will be a great enabler to launch satellites at short notice for disaster management or for military usage in case of conflict. This would also open up big commercial avenues in the space for India and off-course related spin-offs.