Countdown begins for Saturday’s Gaganyaan First unmanned flight test

Chennai, Oct 20 : The countdown for the launch of first unmanned

Flight Test Vehicle Abort Mission-1 (TV-D1) to demonstrate the crew

escape system of the Gaganyaan programme, commenced at 7.30 pm

on at SHAR Range Sriharikota on Friday evening.

It will be a 12.5 hr countdown, ISRO said.

ISRO in an update said “Mission Gaganyaan: TV-D1 Test Flight. The

countdown leading to the launch at 08:00 Hrs. IST on October 21, 2023,

has commenced.”

The launch of the short duration mission will take place from the First

Launch Pad at 0800 hrs on Saturday morning and the entire mission

will last 531 secs (about nine minutes).

This flight test will mark a major milestone in the overall Gaganyaan

programme–which will be India’s first manned mission to space–and

will define the in-flight abort demonstraton of Crew Escape System

(CES) at Mach Number 1.2 with the newly developed Test Vehicle

followed by Crew Module Separation and Recovery.

The objective of the mission is Flight demonstration and evaluation

of Test Vehicle sub systems, Crew Escape System including various

separation systems and Crew Module characteristics & deceleration

systems demonstration at higher altitude and its recovery.

The 35 m tall Liquid Propelled Single Stage Test Vehicle, weighing

about 44 ton, uses a modified Vikas engine with 4,520 kg Crew Module

(CM)– a single walled unpressurised aluminium structure– and CES

mounted at its fore end.

“The entire flight sequence, right from lift off to the crew module touchdown

at sea about 10 km from Sriharikota, with the deployment of parachutes, will

last 531 seconds”, ISRO said.

It said about 60 seconds after the lift off, the test vehicle — crew

escape system will get separated at an altitude of 11.7 km and

another 30 seconds later, the CM-CES will get separated at an

altitude of 16.7 km at a velocity of 148.7 m/s.

Subsequently, the abort sequence will be executed autonomously

commencing with the separation of CES and deployment of series

of parachutes, finally culminating in the safe touchdown of the CM

in the sea, about 10 km from the coast of Sriharikota, the Space

Agency said.

“The CM will splash down In the sea at about 10 km from Sriharikota

and would float until it was recovered by the Indian Navy. The recovery

ships will reach the CM and a team of divers will attach a buoy, hoist

it using a ship crane, and bring it to the shore.