Preparations for the Flight Test Vehicle Abort Mission-1 (TV-D1)

The Indian Space Research Organisation (ISRO) on Saturday said it is on course to commence unmanned flight tests for the country’s ambitious Gaganyaan mission, and preparations are underway for the Flight Test Vehicle Abort Mission-1 (TV-D1).

In a post on social media platform ‘X, the space agency said, “ISRO to commence unmanned flight tests for the Gaganyaan mission. Preparations for the Flight Test Vehicle Abort Mission-1 (TV-D1), which demonstrates the performance of the Crew Escape System, are underway.”

According to ISRO, the first development flight Test Vehicle (TV-D1) is in the final stages of preparation.

Officials had earlier indicated that TV-D1 launch is likely by this month-end.

The Test Vehicle is a single-stage liquid rocket developed for this abort mission. The payloads consist of the Crew Module (CM) and Crew Escape Systems (CES) with their fast-acting solid motors, along with CM fairing (CMF) and Interface Adapters.

This flight will simulate the abort condition during the ascent trajectory corresponding to a Mach number of 1.2 encountered in the Gaganyaan mission, it said. “CES with CM will be separated from the Test Vehicle at an altitude of about 17 km. Subsequently, the abort sequence will be executed autonomously commencing with the separation of CES and deployment of the series of parachutes, finally culminating in the safe touchdown of CM in the sea, about 10 km from the coast of Sriharikota,” ISRO said.

The CM, after integration underwent various electrical testing at ISRO’s facility in Bengaluru, including an acoustic test, and was dispatched to Satish Dhawan Space Centre in Sriharikota (SDSC SHAR) on August 13.

At Satish Dhawan Space Centre, it will undergo vibration tests and pre-integration with the Crew Escape System, before final integration to the Test Vehicle at the launch pad.

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, ISRO said, adding that the success of this test flight will set the stage for the remaining qualification tests and unmanned missions, leading to the first Gaganyaan human spaceflight mission with Indian astronauts.

CM is where the astronauts are contained in a pressurised earth like atmospheric condition during the Gaganyaan space mission. The CM for the Gaganyaan mission is in different stages of development.

For the TV-D1, the CM is an unpressurised version that has completed its integration and testing and is ready to be shipped to the launch complex.

This unpressurised CM version has to have an overall size and mass of actual Gaganyaan CM, the space agency said, adding it houses all the systems for the deceleration and recovery.

“With its complete set of parachutes, recovery aids actuation systems and pyros. The avionics systems in CM are in a dual redundant mode configuration for navigation, sequencing, telemetry, instrumentation and power. The CM in this mission is extensively instrumented to capture the flight data for evaluation of the performance of various systems,” it said.

The CM will be recovered after touchdown in the Bay of Bengal, using a dedicated vessel and diving team from the Indian Navy.