ISRO validates parachute-based deceleration system for Gaganyaan with IADT-01 near Sriharikota

The Integrated Air Drop Test (IADT-01) performed by ISRO on Sunday near Sriharikota marks an essential step in the system-level qualification of the parachute-based deceleration system for the Gaganyaan programme, ISRO has said.

The space agency said the test at the Satish Dhawan Space Centre (SDSC), Sriharikota, "successfully demonstrated the objective of end-to-end performance validation of the critical parachute-based deceleration system of the Crew Module for Gaganyaan mission in one of the typical mission scenarios." It described the exercise as part of the "system level qualification of parachute-based deceleration system, in which a simulated Crew Module (CM), encompassing the deceleration system is dropped using a helicopter." Explaining its purpose, ISRO said, in a press release issued late on Sunday, "In Gaganyaan missions, parachute-based deceleration system is employed during the terminal phase of crew module descent to reduce the touchdown velocity to an acceptable limit for safe landing on sea." The parachute system tested was "the same as that of Gaganyaan missions" and comprised ten parachutes -- two Apex Cover Separation (ACS), two Drogue, three Pilot and three Main canopies.

The 4.8-tonne simulated Crew Module was released from about 3 km altitude using the Indian Air Force's Chinook heavy-lift helicopter. "The deceleration system initiation began with firing of ACS Mortar, which deploys the Ã2.5 m ACS parachutes, which is followed by the separation of Apex cover," ISRO said.

Drogue parachutes provided the first stage of deceleration, before being released to allow three Pilot parachutes to deploy the three Main parachutes of 25 metres diameter.

"Further, main parachutes reduced the terminal velocity of the simulated Crew Module to about 8m/s. After touchdown, the Main parachutes were released using parachute releasers. These parachutes, totaling ten in number, deployed in a precise sequence to gradually decrease the velocity of the Crew Module for safe touchdown," the agency said.

The test simulated "a possible abort scenario on the launch pad," with onboard avionics commanding the deceleration sequence and telemetering data to ground.

Post splashdown, "the simulated Crew Module was successfully recovered and ferried back on INS Anvesha to Chennai port," ISRO added.

The agency said "extensive modeling of CM as well as helicopter was carried out to address the dynamics of underslung body" and multiple trial sorties were completed before clearance by the Test Authorisation Board (TAB).

Apart from ISRO centres, "other governmental agencies, including DRDO, Indian Air Force, Indian Navy and Indian Coast Guard also contributed in the successful accomplishment of this major test," ISRO said.

"Similar tests at different deployment conditions are planned in the forthcoming days," it added.