• ISRO achieved a major milestone by successfully carrying out the landing mission of its Reusable Launch Vehicle (RLV) named ‘Pushpak’ from the Aeronautical Test Range (ATR) in Karnataka’s Chitradurga on March 22.

• The RLV LEX-02 landing experiment is the second of the series conducted at Aeronautical Test Range.

• After the RLV-LEX-01 mission was accomplished last year, RLV-LEX-02 demonstrated the autonomous landing capability of reusable launch vehicle (RLV) from off-nominal initial conditions at release from helicopter.

How was the experiment conducted?

• The RLV was made to undertake more difficult maneuvers with dispersions, correct both cross-range and downrange and land on the runway in a fully autonomous mode.

• The winged vehicle, called ‘Pushpak’, was lifted by an Indian Air Force Chinook helicopter and was released from 4.5 km altitude. 

• After release at a distance of 4 km from the runway, Pushpak autonomously approached the runway along with cross-range corrections. 

• It landed precisely on the runway and came to a halt using its brake parachute, landing gear brakes and nose wheel steering system.

• This mission successfully simulated the approach and high-speed landing conditions of RLV returning from space.

Reusable Launch Vehicle

• RLV is essentially a space plane with a low lift to drag ratio requiring an approach at high glide angles that necessitates a landing at high velocities of 350 kmph. 

• It utilises several indigenous systems. Localised navigation systems based on pseudolite systems, instrumentation, and sensor systems, etc were developed by ISRO. 

• Digital Elevation Model (DEM) of the landing site with a Ka-band Radar Altimeter provided accurate altitude information. 

• Extensive wind tunnel tests and CFD simulations enabled aerodynamic characterisation of RLV prior to the flight. 

• Adaptation of contemporary technologies developed for RLV-LEX makes  other operational launch vehicles of ISRO more cost-effective.

• With this second mission, ISRO has re-validated the indigenously developed technologies in the areas of navigation, control systems, landing gear and deceleration systems essential for performing a high-speed autonomous landing of a space-returning vehicle.

• The winged body and all flight systems used in RLV-LEX-01 were reused in the RLV-LEX-02 mission after due certification/clearances. 

• Hence, reuse capability of flight hardware and flight systems is also demonstrated in this mission.

• Based on the observation from RLV-LEX-01, the airframe structure and landing gear were strengthened to tolerate higher landing loads.

• The mission was accomplished by Vikram Sarabhai Space Centre (VSSC) along with the Liquid Propulsion System Centre (LPSC) and the ISRO Inertial Systems Unit (IISU). 

• ISRO has been working on reusable technology for reducing the cost of access to space, including the development of a winged body unmanned reusable launch vehicle for launching payloads into Low Earth Orbits.

• In May 2016, ISRO had demonstrated the re-entry of its winged vehicle Reusable Launch Vehicle–Technology Demonstrator (RLV-TD) in the HEX mission.

• ISRO successfully developed a scaled down (1:5) technology demonstration version of RLV-TD vehicle and carried out the first experimental mission from Satish Dhawan Space Centre, Sriharikota. 

• In this mission, critical technologies such as autonomous navigation, guidance and control and reusable thermal protection system were successfully demonstrated.

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