RLV: India’s first reusable space shuttle
India launched its first experimental indigenous winged Reusable Launch Vehicle (RLV) from Sriharikota spaceport in Andhra Pradesh on Monday.
The RLV Technology Demonstration (RLV-TD), that aims to ultimately put satellites into orbit around earth and then re-enter atmosphere, will be carried up on a solid rocket motor. The nine-metre long rocket weighs 11 tonnes.
“The launch window for the RLV-TD is between 7 am and 11 am,” a senior ISRO official said.
Very similar in its looks to the US space shuttle, the double delta-winged RLV-TD is a scale model almost six times smaller than the final version. The 6.5-m-long ‘aeroplane’-like structure weighs 1.75 tonnes and will be hoisted into the atmosphere on a special rocket booster.
The RLV-TD is described as “a very preliminary step” in the development of a reusable rocket, whose final version is expected to take 10-15 years.
Explaining the importance of the experimental RLV, Indian Space Research Organisation (ISRO) Chairman Kiran Kumar said it is essentially an attempt by India to bring down the cost of making infrastructure for space.
“We are designing for the first time a winged body which will come back from space… We will be launching from Sriharikota, and the plane-like winged body will land in the ocean, in the Bay of Bengal. Ultimately, the objective will be this winged body will come and land on the Sriharikota island,” Kumar told PTI.
The development of an RLV — sometimes referred to as a space truck or a space shuttle — has not been the top priority at ISRO, evident from the fact that there has been no technology demonstration despite an RLV development programme being in the pipeline for six to seven years now.
One of the first trials of an RLV was announced by ISRO as far back as 2010 but was put off due to technical reasons. Another was hinted at in 2015 but was again grounded over technical issues.
Much of the attention in recent years at ISRO was focused on the development of the heavy lift Geosynchronous Satellite Launch Vehicle (GSLV) and its high-end version, the GSLV-Mk III, to enable the space organisation to break into the lucrative market of launching large communication satellites weighing over 2000 kg.
A decision in 2011 by the US government to shut down NASA’s space shuttle programme on the grounds of viability also caused a drop in interest in the development of an RLV at ISRO.
A renewed interest worldwide through the pioneering efforts of private companies like the Elon Musk-founded SpaceX in the US in creating cost-effective launch vehicles, that can fly hundreds of times into space in their lifespan, appears to have also rekindled fresh efforts at ISRO.
On Monday, a technology RLV demonstrator will be flown to an altitude of 70 km in the sky before being brought back to land in the sea. The mission, known as the hypersonic flight experiment, is expected to last about 10 minutes from liftoff to splashdown.
The hypersonic flight experiment (HEX) will be followed by the landing experiment (LEX), return flight experiment (REX) and scramjet propulsion experiment (SPEX).
While companies like SpaceX have moved away from using winged spaceplanes for their RLV plan, ISRO feels a winged spacecraft provides more accuracy for landings.
Though manned space flights are an ultimate goal of RLVs, the major advantage is reducing the cost of space launches and making space travel more affordable. “The cost of access to space is the major deterrent in space exploration and space utilisation. A reusable launch vehicle is the unanimous solution to achieve low-cost, reliable and on-demand space access,” according to ISRO.
“Nearly 80 to 87 per cent of the cost in a space launch vehicle goes into structure of the vehicle. The cost of propellants is minimal in comparison. By using RLVs, the cost of a launch can be reduced by nearly 80 per cent,” says Dr K Sivan, Director of Vikram Sarabhai Space Centre.