ISRO successfully conducts 3rd and final landing experiment of Reusable Launch Vehicle ‘Pushpak’

The Indian Space Research Organisation (ISRO) accomplished the third landing experiment of the Reusable Launch Vehicle (RLV LEX-03) named ‘Pushpak’ on Sunday. According to a statement by the space agency, the test was carried out at 07:30 IST at the Aeronautical Test Range (ATR) located in Karnataka's Chitradurga.

"Hat-trick for ISRO in RLV LEX! ISRO achieved its third (and final) consecutive success in the Reusable Launch Vehicle (RLV) Landing EXperiment (LEX) on June 23, 2024. "Pushpak" executed a precise horizontal landing, showcasing advanced autonomous capabilities under challenging conditions. With the objectives of RLV-LEX accomplished, ISRO embarks into RLV-ORV, the orbital reusable vehicle," ISRO wrote on X.

ISRO chairman S Somanath congratulated the team for their dedication in sustaining the streak of success in such “complex missions.” J Muthupandian serves as the Mission Director, while B Karthik assumes the role of Vehicle Director for this mission.

What is the aim?

This mission replicated the approach, landing interface, and high-speed landing conditions for a vehicle reentering from space, highlighting ISRO's proficiency in acquiring crucial technologies for Reusable Launch Vehicle (RLV) development.

As a result of this mission, the sophisticated guidance algorithm addressing longitudinal and lateral plane error corrections, vital for future Orbital Re-entry Missions, has been authenticated.

Technical aspects of RLV LEX mission - Pushpak

- The RLV LEX-03 mission is built upon the successes of previous missions – RLV LEX-01 and LEX-02 missions – demonstrating the autonomous landing capability of the RLV under more challenging conditions.

- The winged vehicle, 'Pushpak', was released from an Indian Air Force Chinook Helicopter at an altitude of 4.5 km. Pushpak autonomously executed cross-range correction manoeuvres from a release point 4.5 km away from the runway, approaching and landing precisely at the runway centerline.

- Due to its low lift-to-drag ratio aerodynamic configuration, Pushpak landed at a velocity exceeding 320 kmph, compared to commercial aircraft (260 kmph) and typical fighter aircraft (280 kmph).

- After touchdown, the vehicle's velocity was reduced to nearly 100 kmph using a brake parachute, followed by employing landing gear brakes for further deceleration.

- Pushpak autonomously maintained a stable and precise ground roll along the runway using its rudder and nose wheel steering system during the ground roll phase.

- The RLV-LEX utilised multisensor fusion, including an Inertial sensor, Radar altimeter, Flush air data system, Pseudolite system, and NavIC.

- The RLV-LEX-03 mission reused the winged body and flight systems from the LEX-02 mission without any modification, showcasing ISRO's capability to design reusable flight systems for multiple missions.

Collaborative effort

The mission, spearheaded by Vikram Sarabhai Space Centre (VSSC) was a collaborative effort involving various ISRO centres such as SAC, ISTRAC, SDSC-SHAR, along with significant support from the Indian Air Force (IAF), Aeronautical Development Establishment (ADE), Aerial Delivery Research and Development Establishment (ADRDE), Regional Centre for Military Airworthiness (RCMA) under the Centre for Military Airworthiness and Certification (CEMILAC), National Aerospace Laboratories (NAL), Indian Institute of Technology, Kanpur, Indian aerospace industrial partners, Indian Oil Corporation of India, and Airport Authority of India.

S Unnikrishnan Nair, Director of VSSC, highlighted that this consistent success bolsters ISRO's confidence in the critical technologies necessary for future orbital re-entry missions.