After several delays owing to weather, the Indian Space Research Organisation (Isro) landed its under-development Reusable Launch Vehicle (RLV), dubbed Pushpak, for the third time.
The test, known as RLV LEX-03, was conducted at 07:10 IST at the Aeronautical Test Range (ATR) in Chitradurga, Karnataka.
This mission marks Isro's third consecutive success in the series of RLV landing experiments, following the achievements of RLV LEX-01 and LEX-02.
Pushpak, the winged vehicle, was released from an Indian Air Force Chinook Helicopter at an altitude of 4.5 km. From a release point 4.5 km away from the runway, Pushpak autonomously executed cross-range correction manoeuvres, approached the runway, and performed a precise horizontal landing at the runway centerline.
The vehicle's low lift-to-drag ratio aerodynamic configuration resulted in a landing velocity exceeding 320 kmph, compared to 260 kmph for a commercial aircraft and 280 kmph for a typical fighter aircraft.
After touchdown, the vehicle's velocity was reduced to nearly 100 kmph using its brake parachute, followed by the employment of landing gear brakes for deceleration and stop on the runway. During the ground roll phase, Pushpak utilized its rudder and nose wheel steering system to autonomously maintain a stable and precise ground roll along the runway.
The RLV LEX-03 mission re-demonstrated the autonomous landing capability of the RLV under more challenging release conditions, including a cross range of 500 meters against 150 meters for LEX-02 and more severe wind conditions.
This mission simulated the approach and landing interface and high-speed landing conditions for a vehicle returning from space, reaffirming ISRO's expertise in acquiring the most critical technologies required for the development of a Reusable Launch Vehicle (RLV).
Through this mission, the advanced guidance algorithm catering to longitudinal and lateral plane error corrections, essential for future Orbital Re-entry Missions, has been validated. The RLV-LEX uses multisensor fusion, including sensors like the Inertial sensor, Radar altimeter, Flush air data system, Pseudolite system, and NavIC.
The mission reused the winged body and flight systems from the LEX-02 mission without any modification, demonstrating the robustness of ISRO's capability to design reusable flight systems for multiple missions. The mission, led by the Vikram Sarabhai Space Centre (VSSC), was a collaborative effort involving multiple ISRO centres, the Indian Air Force, and various other research and development establishments and industrial partners.
