ISRO’s Reusable Launch Vehicle
What is it?
- Reusable Launch Vehicle is a launch system that is capable of launching a payload into space more than once.
- It would launch spacecraft, including satellites, into space and re-enter the earth’s atmosphere withstanding extreme pressure and heat conditions and land in an intended spot
- Normally, a launch vehicle burns out on re-entering the atmosphere and hence cannot be reused. The challenge is thus, to develop a launch vehicle which can withstand the heat on re-entry into earth’s atmosphere and can be retrieved for reuse.
Why in News?
- India has successfully launched the first technology demonstrator of indigenously made Reusable Launch Vehicle (RLV). It was called Reusable Launch Vehicle- Technology Demonstrator (RLV-TD)
- The experiment is also known as hypersonic flight experimentas it will also test the ability of the vehicle to withstand re-entry at speeds higher than that of sound.
- This was the first time that ISRO flew a winged body from the space port at Sriharikota and brought it back to land on a make-shift runway in the Bay of Bengal
- Three objectives for the RLV-TD launch:
To test the characterisation of the aero-thermo dynamics of hypersonic flights
To test the autonomous mission management of hypersonic vehicles
To test the necessary re-entry technology for the vehicle
- The 6.5 meter long Re-usable Launch Vehicle – Technology Demonstrator (RLV-TD) weighs about 1.7 tons.
- Built over five years by a team of 600 scientists, the project cost around Rs 95 crore.
Technological Details
- The first stage or special booster is powered using a solid fuel. The booster rocket, carrying a winged-body aerospace vehicle (RLV-TD) took off from the spaceport. It climbed for about 90 seconds before its burnout. Coasting to an altitude of 56 km, where it was separated from the booster, RLV-TD inclined further to 65 km.
- From an altitude of 65 km, the vehicle made a re-entry into the earth’s atmosphere at Mach 5 (five times the speed of sound)
- During the descent phase, small thrusters will help the vehicle navigate itself to the landing area
- Steered by its navigation, guidance and control system for safe descent, the vehicle glided down to the defined landing spot in the Bay of Bengal, 450 km from Sriharikota.
- ISRO will also use cutting-edge technology to shield the launch vehicle from intense heat to reduce, if not completely eliminate, refurbishment expenses. Getting this right would enable the vehicle to be reused within a very short span of time
Benefits of Reusable Launch Vehicle
- Currently, a major part of satellite launch cost is comprised of building the launch vehicle. These vehicles can’t be reused as they are burnt on re-entry into the atmosphere. Hence, RLVs are being seen as the unanimous solution towards achieving low cost, reliable and on-demandspace access.
Scientists at ISRO believe that they could reduce the cost by as much as 10 times if reusable technology succeeds, bringing it down to $2,000 per kg.
- If ISRO’s plans work out, it should be able to break even after 25 to 50 launches, bringing down the cost of further launches on the same vehicle.
- ISRO will be able to earn tremendous amounts of foreign exchange by offering the cheap launch services of RLV
- India can use the RLV to launch the satellites of smaller neighbours and hence, earn geostrategic clout in the process.
- Being dubbed a complete ‘Made-in-India’ effort, the Reusable Launch-Vehicle – Technology Demonstrator (RLV-TD) is the first time that ISRO launches an indigenous space craft with delta wings.
Other Reusable Launch Vehicles worldover and comparison with Indian Version
- No completely reusable orbital launch system is currently in use
- However, several at least partially reusable systems are currently under development, such as the Falcon 9 full thrust (first stage).
- SpaceX, a player inprivate launch market succeeded in converting its Falcon 9expendable launch vehicle into a partially reusable vehicle by returning the first stage for reuse.
- The test launch is considered a significant step in India’s space endeavour. It’s especially important because in 2011, the U.S.’s Nasa abandoned its reusable space shuttle project.
- Learning from the mistakes of NASA, ISRO will not use the same reusable vehicle to launch satellites and carry astronauts as it drastically reduces the payload capacity and thereby increases the cost per kg.
- Avatar-RLV- ("Aerobic Vehicle for Transatmospheric Hypersonic Aerospace TrAnspoRtation") is a study concept for unmanned single-stage re-usable seaplane capable of horizontal takeoff and landing.
It is under development by Defence Research and Development Organisation.
It is for low cost military and commercial satellite launches
It has no connection with the RLV-TD; it is a separate project.
Way forward
- ISRO plans to evaluate various technologies via RLV-TD, namely, hypersonic flight, autonomous landing, powered cruise flight and hypersonic flight using air-breathing propulsion.
- These technologies will be developed in phases through a series of experimental flights.
- The first in the series of experimental flights is the hypersonic flight experiment (HEX) followed by the landing experiment (LEX), return flight experiment (REX) and scramjet propulsion experiment (SPEX).
- The final version of the Reusable Launch Vehicle will take about 10-15 years to be ready
SOURCES
