- ISRO successfully conducted the Reusable Launch Vehicle Autonomous Landing Mission (RLV LEX). The test was conducted at the Aeronautical Test Range (ATR), Chitradurga, Karnataka in the early hours on April 2, 2023.
- The RLV took off at 7:10 am IST by a Chinook Helicopter of the Indian Air Force as an underslung load and flew to a height of 4.5 km (above MSL). 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 10 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. With that, ISRO successfully achieved the autonomous landing of a space vehicle.
- In a first in the world, a winged body has been carried to an altitude of 4.5 km by a helicopter and released for carrying out an autonomous landing on a runway.
- RLV is essentially a space plane with a low lift to drag ratio requiring an approach at high glide angles that necessitated a landing at high velocities of 350 kmph.
- LEX utilized 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 aerodynamic characterization of RLV prior to the flight. Adaptation of contemporary technologies developed for RLV LEX turns other operational launch vehicles of ISRO more cost-effective.
- RLV LEX employs several indigenous systems such as precision navigation hardware and software, pseudolite system, Kaband radar altimeter, NAVIC receiver, indigenous landing gear, aerofoil honey-comb fins and brake parachute system.
RLV LEX:-
- LEX began with an integrated navigation test in 2019 and was followed by a number of engineering model tests and captive phase tests in subsequent years.
- ISRO had demonstrated the reentry of its winged vehicle RLV-TD in the HEX mission in May 2016.
- The re-entry of a hypersonic sub-orbital vehicle marked a major achievement in developing reusable launch vehicles.