Introduction
The Indian government recently gave ISRO the go ahead for developing the Re-entry Launch Vehicle (RLV) technology demonstrator.
The RLV has been conceived by ISRO as a space launch system that will significantly cut down launch cost from the present level of around $12,000 / kg.
An Innovative Approach
In pursuit of its goal ISRO has adopted an approach that is radically different from the approach adopted by NASA for its Space Shuttle progam. Besides it is a more cautious and cost effective approach.
Unlike NASA’s Space Shuttle, which powers itself into orbit around the earth and subsequently de-orbits and re-enters the atmosphere to glide back to a landing, ISRO’s RLV is not designed to enter orbit. It is a pure launcher. Not a spacecraft cum launcher. After lofting a recoverable satellite into orbit the launch vehicle will immediately re-enter the atmosphere and glide back for a conventional landing.
The ISRO approach is more akin to the concepts being pioneered by Space Launch Corporation under DARPA funding. Interestingly, Space Launch Corporation is partnering with Scaled Composites of SpaceShip One fame for developing microsatellite launch capability using technology developed for SpaceShip One.
Phased Development
ISRO plans to achieve RLV capability in three phases.
In the first phase ISRO will launch a 450 kg satellite, dubbed the Space Recovery Experiment (SRE). The SRE will be launched along with CARTOSAT-2, by PSLV, sometime in late 2005 or early 2006. The satellite will remain in space for 3-30 days before splashing down in the sea. The payloads carried by the SRE for experiments with quasi crystal growth and biomimetic material synthesis, will be retrieved and studied
The project will try out important re-entry technology, which will cover issues like precise control of the angle of entry into the atmosphere, materials technology to minimize the chance of burn-up at the high temperatures generated during re-entry, and control of the spacecraft to ensure its landing at the desired spot on the ground.
The SRE has already been tested 3 times using airdrops from IAF helicopters. It touched down once on land and twice on a lake. A test touch down in the sea is planned in the near future.
In the meantime work has already started on the RLV-TD for a possible test by 2010. The RLV will possess wings and tail fins, and will be launched atop a solid booster, similar to the ones on the PSLV. The booster will then separate and fall away, and the craft will go on to make an unpowered ascent.
It will then re-enter the atmosphere at hypersonic speed, which will be slowed down using aerodynamic breaking techniques. It will be brought to a gliding, unpowered cruise speed of about 0.8 mach, and slowed down further to make a horizontal landing.
During initial tests the RLV will make unpowered ascents. Eventually, it will be powered by an air breathing scram jet, work on which has already begun at ISRO.
It is hoped that RLV technology will mature by 2015 by which time the solid rocket booster used as the first state will also be recovered and reused. The RLV and the rocket booster will be separately recovered, with the former making a conventional landing on a runway and booster making a parachute landing.
PS I report on Defence matters because India spends nearly 20% of its budget on Defence. Two of Inda's neighbors openly covet her territory and don't foresake the use of violence to get it. Under the circumstances I think it is imperative that all Indians follow matters of defence closely. Our history, distant and recent, is replete with invasions that we invited upon ourselves by not being adequately prepared.
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