Chitradurga: The Indian Space Research Organisation (ISRO) conducted its third Reusable Launch Vehicle (RLV) Landing Experiment (LEX) on June 23 at the Aeronautical Test Range (ATR) in Chitradurga, Karnataka. This marks the final test in the LEX series, executed at 7:10 a.m.
Following the successes of the previous RLV LEX-01 and LEX-02 missions, the RLV LEX-03 test demonstrated the autonomous landing capabilities of the vehicle under more demanding conditions. The release conditions for this experiment featured a cross-range of 500 meters, compared to 150 meters for the LEX-02, alongside more challenging wind conditions, ISRO reported.
On the morning of the test, the winged vehicle, named Pushpak, was released from an Indian Air Force Chinook Helicopter at an altitude of 4.5 kilometers. Pushpak autonomously performed cross-range correction maneuvers from a release point 4.5 kilometers away from the runway, approached, and executed a precise horizontal landing on the runway’s centerline.
ISRO highlighted that the vehicle’s aerodynamic configuration, characterized by a low lift-to-drag ratio, resulted in a landing velocity of over 320 km/h—higher than the typical 260 km/h for commercial aircraft and 280 km/h for fighter jets. After touchdown, the vehicle’s speed was reduced to nearly 100 km/h using a brake parachute, followed by the application of landing gear brakes to decelerate and stop. During the ground roll phase, Pushpak utilized its rudder and nose wheel steering system to maintain a stable and precise trajectory along the runway.
This mission simulated the approach and landing phase, as well as high-speed landing conditions, akin to those a vehicle would encounter when returning from space. ISRO emphasized that this test reaffirms their expertise in developing the critical technologies required for a Reusable Launch Vehicle (RLV).
The advanced guidance algorithm for longitudinal and lateral plane error corrections, crucial for future Orbital Re-entry Missions, was validated through this mission. ISRO noted that the RLV-LEX employs multisensor fusion, incorporating sensors such as the Inertial sensor, Radar altimeter, Flush air data system, Pseudolite system, and NavIC.
Notably, the RLV-LEX-03 mission reused the winged body and flight systems from the LEX-02 mission without modifications, showcasing ISRO’s capability to design and reuse flight systems across multiple missions.
Additionally, this mission provided crucial data by simulating the approach and landing interface and high-speed landing conditions, underscoring ISRO’s expertise in acquiring the critical technologies necessary for the development of RLVs.
