The Indian Space Research Organisation (ISRO) has successfully completed the Reusable Launch Vehicle Autonomous Landing Mission (RLV LEX). The test took place at the Aeronautical Test Range (ATR) in Chitradurga, Karnataka, and demonstrated the autonomous landing of a space vehicle. The RLV is a space plane that requires landing at high velocities of 350 kmph. The RLV was carried to an altitude of 4.5 km by a Chinook Helicopter of the Indian Air Force (IAF) and then released in mid-air. The RLV then performed approach and landing maneuvers using the Integrated Navigation, Guidance & control system and completed an autonomous landing on the ATR air strip.
According to The Indian Express, the Indian Space Research Organisation (ISRO) has successfully achieved the Reusable Launch Vehicle Autonomous Landing Mission (RLV LEX). The test was conducted at the Aeronautical Test Range in Chitradurga, Karnataka. In a statement, ISRO said, “With LEX, the dream of an Indian Reusable Launch Vehicle arrives one step closer to reality.”
This achievement is a first in the world as a winged body was carried to an altitude of 4.5 km by a helicopter and released for carrying out an autonomous landing on a runway. The RLV is essentially a space plane with a low lift to drag ratio that requires an approach at high glide angles that necessitated a landing at high velocities of 350 kmph.
The RLV took off at 7:10 am IST by a Chinook Helicopter of the Indian Air Force (IAF) as an underslung load and flew to a height of 4.5 km (above Mean Sea Level). Once the predetermined pillbox parameters were attained, based on the RLV’s Mission Management Computer command, the RLV was released in mid-air, at a down range of 4.6 km. Release conditions included ten parameters covering position, velocity, altitude, and body rates, etc. The release of RLV was autonomous. RLV then performed approach and landing maneuvers using the Integrated Navigation, Guidance & control system and completed an autonomous landing on the ATR air strip at 7:40 AM IST.
The autonomous landing was carried out under the exact conditions of a Space Re-entry vehicle’s landing — high speed, unmanned, precise landing from the same return path — as if the vehicle arrives from space. Landing parameters such as Ground relative velocity, the sink rate of Landing Gears, and precise body rates, as might be experienced by an orbital re-entry space vehicle in its return path, were achieved.
The RLV LEX demanded several state-of-the-art technologies, including accurate Navigation hardware and software, Pseudolite system, Ka-band Radar Altimeter, NavIC receiver, indigenous Landing Gear, Aerofoil honey-comb fins, and brake parachute system. LEX utilised several indigenous systems. Localized 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 the design of a unique landing gear system that was successfully tested during the mission.
This achievement is a significant milestone in India’s space exploration journey. With this success, India is one step closer to achieving its dream of developing an Indian Reusable Launch Vehicle. The autonomous landing of a space vehicle is a crucial step towards achieving this dream. ISRO’s dedication and hard work have paid off, and this achievement will inspire and motivate the team to reach new heights in space exploration.
