ISRO's Reusable Launch Vehicle Prototype 'Pushpak' Lands Autonomously After Being Dropped By Helicopter. WATCH

A Chinook helicopter from the Indian Air Force (IAF) carried Pushpak, a winged vehicle, to an altitude of 4.5 kilometres, and released it in a way such that the initial conditions were off-nominal.

After making complex manoeuvres, Pushpak landed autonomously on the runway at the Aeronautical Test Range (ATR) in Chitradurga, Karnataka, at 7:10 am IST on March 22. This was the second leg of ISRO's reusable launch vehicle autonomous landing mission (RLV LEX). 

Source : ISRO

RLV LEX-02: The Indian Space Research Organisation's (ISRO's) reusable launch vehicle prototype 'Pushpak' achieved a fully autonomous landing on a runway, after being dropped mid-air by a helicopter on March 22, 2024. A Chinook helicopter from the Indian Air Force (IAF) carried Pushpak, a winged vehicle, to an altitude of 4.5 kilometres, and released it in a way such that the initial conditions were off-nominal, so that ISRO can evaluate how the spacecraft would perform in unfavourable conditions. 

After making complex manoeuvres, Pushpak landed autonomously on the runway at the Aeronautical Test Range (ATR) in Chitradurga, Karnataka, at 7:10 am IST on March 22. This was the second leg of ISRO's reusable launch vehicle autonomous landing mission (RLV LEX). 

Therefore, the experiment is called RLV LEX-02. The spacecraft is indigenously developed.

The following video shows how the Chinook helicopter carried Pushpak to the pre-determined altitude, released it mid-air, and how the spacecraft landed autonomously. 

RLV-LEX-02: A video collage.

Details:https://t.co/XftP6gaM36

Mighty @IAF_MCC and various ISRO Centres/Units like LPSC, IISU, SAC, SDSC-SHAR, ISTRAC, URSC, etc. fueled the success. pic.twitter.com/IUanvewcaw

— ISRO (@isro) March 22, 2024

More about RLV LEX-02

At the time of its mid-air release, Pushpak was at a horizontal distance of four kilometres from the runway. Since it was released from an off-nominal position, Pushpak performed cross-range (perpendicular to the direction of flight) corrections, and autonomously approached the runway. 

After making a precise landing on the runway, Pushpak came to a halt with the help of its brake parachute, landing gear brakes, and a nose wheel steering system. According to a 2021 study published in Sage Journals, a nose wheel steering system is used to correct small deflection angles during high speed taxiing (the movement of an aircraft on a runway), or to turn at large angles when taxiing is slow. 

ISRO achieved optimal results in terminal phase manoeuvring, landing and energy management, in a fully autonomous mode. This is crucial to the success of future orbital reentry missions.

In the future, ISRO aims to send a reusable launch vehicle to space, and bring it back to Earth. Therefore, RLV LEX-02 simulated the approach as well as high-speed landing conditions that the vehicle will be subject to when returning from space. 

The success of this experiment is significant because it is testament to the fact that ISRO re-validated indigenously developed technologies in the sectors of control systems, deceleration systems, navigation, and landing gear, all of which are important to achieve autonomous landing of a vehicle returning from space at a high speed.