ISRO Achieves Third Consecutive Success in Reusable Launch Vehicle (RLV) Landing Experiment

The Indian Space Research Organisation (ISRO) has proudly achieved a significant milestone with the successful completion of the third consecutive Reusable Launch Vehicle (RLV) Landing Experiment (LEX) on June 23, 2024. This landmark event took place at 07:10 IST at the Aeronautical Test Range (ATR) in Chitradurga, Karnataka, marking a pivotal advancement in India's space exploration capabilities.

Overview of the RLV LEX-03 Mission

Following the success of the RLV LEX-01 and LEX-02 missions, the RLV LEX-03 mission re-demonstrated the autonomous landing capability of the winged vehicle 'Pushpak' under more challenging conditions. Released from an Indian Air Force Chinook Helicopter at an altitude of 4.5 km, Pushpak executed cross-range correction maneuvers from a release point 4.5 km away from the runway. Despite severe wind conditions and a cross-range of 500 m (compared to 150 m in LEX-02), Pushpak successfully performed a precise horizontal landing at the runway centerline.

Pushpak's aerodynamic configuration, with a low lift-to-drag ratio, necessitated a landing velocity exceeding 320 kmph—higher than that of commercial aircraft (260 kmph) and typical fighter aircraft (280 kmph). Upon touchdown, the vehicle's velocity was reduced to nearly 100 kmph using its brake parachute, followed by deceleration via landing gear brakes. The rudder and nose wheel steering system ensured stable and precise ground roll along the runway.

Significance of the Mission

This mission simulated the critical approach and landing interface and high-speed landing conditions akin to a vehicle returning from space. It reaffirmed ISRO's prowess in acquiring essential technologies for developing a Reusable Launch Vehicle (RLV). The advanced guidance algorithm, crucial for longitudinal and lateral plane error corrections, was validated during this mission, marking a significant step towards future Orbital Re-entry Missions.

The RLV-LEX used multi-sensor fusion, incorporating sensors like the Inertial sensor, Radar altimeter, Flush air data system, Pseudolite system, and NavIC. Remarkably, the winged body and flight systems used in LEX-03 were reused from the LEX-02 mission without any modifications, demonstrating ISRO's robust design and reuse capabilities.

Collaborative Effort and Leadership

The RLV LEX-03 mission was a collaborative endeavor led by VSSC, with contributions from multiple ISRO centers including SAC, ISTRAC, and SDSC-SHAR. The Indian Air Force (IAF), Aeronautical Development Establishment (ADE), Aerial Delivery Research and Development Establishment (ADRDE), Regional Centre for Military Airworthiness (RCMA) under 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 played pivotal roles in this mission's success.

Shri. S Somanath, Chairman, ISRO - Indian Space Research Organization / Secretary, Department of Space, lauded the team for their consistent success in executing such complex missions. Dr. S Unnikrishnan Nair, Director of VSSC - Indian Space Research Organization , highlighted that this achievement enhances ISRO's confidence in the critical technologies required for future orbital re-entry missions.

The mission was directed by Shri. J Muthupandian and the vehicle was led by Shri. B Karthik.