Gaganyaan: Countdown to India's space crew module's first test flight to start today

The countdown for the first Flight Test Vehicle Abort Mission-1 (TV-D1) on Saturday to demonstrate the crew escape system of the Indian rocket that would carry its astronauts to space will begin at
8 am today, a senior Indian Space Research Organisation (ISRO) official said.

India plans to orbit its astronauts in space in its own rocket for the first time sometime in 2025 and testing the crew escape system is part of that and the flight of TV-D1 will happen at 8 a.m. on Saturday, the official told IANS. This will be the first of the four test flights, said ISRO Chairman S.Somanath.

According to ISRO, the Saturday flight is for flight demonstration and evaluation of test vehicle sub systems; flight demonstration and evaluation of Crew Escape System including various separation systems and crew module characteristics and deceleration systems demonstration at higher altitude and its recovery.

Measuring about 35 tall and weighing about 44 tonnes, the test vehicle/rocket uses a modified Vikas engine which is powered by liquid fuel. The crew module and crew escape system are mounted at the fore end of the rocket. The entire flight sequence -- from the test rocket's lift-off to the crew module touchdown at the sea with the deployment of parachutes -- will take about 531 seconds or about nine minutes.

According to ISRO, the mass of the crew module is 4,520 kg and is a single-walled unpressurised aluminium structure. At about 60 seconds into the flight and at an altitude of 17 km, the test vehicle and the crew escape system will get separated. And 91 seconds after the lift-off, the crew module and crew escape system will get separated.

Subsequently, the abort sequence will be executed autonomously commencing with the separation of crew escape system and deployment of the series of parachutes, finally culminating in the safe touchdown of the crew module in the sea, about 10 km from the coast of Sriharikota, ISRO said. The crew module will house the astronauts in a pressurised earthlike atmospheric condition during the real human space mission.

Currently the crew module for the Gaganyaan mission is in different stages of development. The TV-D1 is an unpressurised version but has an overall size and mass of actual Gaganyaan crew module and would house all the systems for the deceleration and recovery. The avionics systems in the crew module are in a dual redundant mode configuration for navigation, sequencing, telemetry, instrumentation and power.

According to ISRO, the crew module in this mission is extensively instrumented to capture the flight data for evaluation of the performance of various systems. The deceleration of the crew module will be done with parachutes with pyro systems. The parachute deployment initiation will be done when the crew module is at about 17 km altitude.

The crew module will splash down on the sea at about 10 km from the launch pad at Sriharikota at about 531 seconds after the rocket's lift off and would float till it was recovered by the Indian Navy. Recovery ships will approach the crew module and a team of divers will attach a buoy, hoist it using a ship crane and bring it to the shore.

The crew escape system will hit the sea at about 14 km from Sriharikota. This Test Vehicle mission with this crew module is a significant milestone for the overall Gaganyaan programme as a near-complete system is integrated for a flight test. The success of this test flight will set the stage for the remaining qualification tests and unmanned missions, leading to the first Gaganyaan mission with Indian Astronauts, ISRO said.