ISRO successfully conducts reusable launch vehicle autonomous landing mission

The Indian Space Research Organisation (ISRO) successfully conducted the Reusable Launch Vehicle Autonomous Landing Mission (RLV LEX) on Sunday.

The test was conducted at the Aeronautical Test Range (ATR) in Chitradurga, Karnataka, the Bengaluru-headquartered national space agency said.

ISRO conducted the experiment in collaboration with the Air Force and Defence Space Research Organisation early today.

How landing was carried out?

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 it 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 RL LEX demanded several state-of-the-art technologies including accurate Navigation hardware and software, Pseudolite system, Ka-band Rada: Altimeter, NavIC receiver, indigenous Landing Gear, Aerofoil honey-comb fins and brake parachute system.

Winged body carried by helicopter

In a first in the world, a winged body has been carried to an altitude of 4.5 km by 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 utilize 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 RL prior to the flight Adaptation of contemporary technologies developed for RV LEX turns other operational launch vehicles ofISRO more cost-effective.

ISRO had demonstrated the re-entry of its winged vehicle RLV-TD in the HEX mission in May 2016. The re-entry of a hypersonic sub-orbital vehicle marked : major accomplishment in developing Reusable Launch Vehicles.

LEX mission achieves final approach phase

In HEX, the vehicle landed on a hypothetical runway over the Bay of Bengal. Precise landing or a runway was an aspect not included in the HEX mission. The LEX mission achieved the final approach phase that coincided with the re-entry return flight path exhibiting an autonomous, high-speed (350 kmph) landing.

The LEX began with an Integrated Navigation test in 2019 and followed multiple Engineering Model Trials and Captive Phase tests in subsequent years.