ISRO successfully launched the Gaganyaan’s Flight Test Vehicle Abort Mission-1 (TV-D1) from Satish Dhawan Space Centre in Sriharikota.
| Photo Credit: ANI

After the successful Test Vehicle-D1 (TV-D1) mission on October 21, the Indian Space Research Organisation (ISRO) has lined up more test missions in the months ahead for the Gaganyaan programme.

Upcoming tests include the TV-D2 mission, the G-X unmanned orbital demonstration flight, an Integrated Air-Drop Test (IADT) and a Pad Abort Test, S. Unnikrishnan Nair, Director, Vikram Sarabhai Space Centre (VSSC), told The Hindu.

A crew module with service module will be used in the G-X mission. This unmanned mission, to be launched aboard a human-rated LVM3, will have ‘Vyommitra’ – the ‘female’ robot astronaut designed and developed by the ISRO Inertial Systems Unit (IISU) – on board. In this mission, ISRO will put to test control systems, a “reduced version” of the life support system for the crew, thermal protection systems and the parachute systems.

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Meanwhile, the Test Vehicle (TV) development programme will continue parallelly. TV-D2 will be the second of four tests planned for demonstrating in-flight abort capability under different initial conditions with respect to the launch vehicle. Unlike TV-D1, TV-D2 will also have onboard a control system for re-orienting the attitude of the crew module once it separates.

The test vehicle will be the same, expendable version based on the L40 strap-on of the multi-purpose vehicle Geosynchronous Satellite Launch Vehicle (GSLV) used in TV-D1 mission. TV-D1 demonstrated the in-flight abort of the Crew Escape System (CES) at 1.2 Mach speed, which was followed by the separation of the crew module and its recovery from the sea.

At the same time, ISRO is also examining whether the TV-D1 crew module, recovered from the sea after a parachute-assisted splash-down, can be reused for future tests. The space agency is looking into this possibility, Dr. Unnikrishnan Nair said. The lead unit of ISRO for launch vehicles, VSSC was responsible for the structural design and manufacture of the unpressurised crew module used for the test.

As the module had come into contact with salt water, only a detailed inspection can tell whether it can be reused and in what capacity. ‘‘We are working out a plan to reuse it. We need to open and clean it and see what can be done. Efforts will be taken to divert it for the appropriate test programme under Gaganyaan,” he said.

ISRO will use an XL variant of the PSLV to place the Aditya-L1 spacecraft in a low earth orbit. Photo: isro.gov.in

Scientists at the Space Physics Laboratory (SPL) under the Vikram Sarabhai Space Centre (VSSC) here are getting ready to unravel the secrets of the solar wind as the Aditya-L1 mission, meant to study the sun, lifts off in September.

The Plasma Analyser Package for Aditya (PAPA) payload aboard Aditya-L1, one of seven scientific payloads aboard the challenging mission, was developed by the SPL to gain deeper insights into the phenomenon of the ‘solar wind,’ as the constant stream of charged particles from the sun is called.

S. Somanath, Chairman, Indian Space Research Organisation (ISRO), said on Saturday that the mission would lift off from Sriharikota in the first week of September.

Energy of electrons

The SPL’s PAPA payload will study the composition of the solar wind, a senior ISRO official said. “It will look at the energy of electrons and the energy and mass of protons and ions in it. The study will also cover the angular variations,” the official said.

For the SPL, the Aditya-L1 mission is yet another big occasion, coming close on the heels of the Chandrayaan-3 lunar mission on which it had two important scientific payloads. ISRO describes Aditya-L1 as the ‘‘first space-based Indian mission to study the sun’‘ from a halo orbit around the Lagrangian point 1 (L1) of the sun-earth system.

Weighing roughly 8 kg, PAPA shares space on the Aditya-L1 spacecraft with six other payloads developed by sister ISRO units and other scientific establishments collaborating with ISRO. According to ISRO, the payloads are designed ‘‘to study the chromosphere, the photosphere and the outermost layers of the sun using electromagnetic and particle detectors.’‘

ISRO will use an XL variant of the Polar Satellite Launch Vehicle (PSLV) to place the Aditya-L1 spacecraft in a low earth orbit. Mr. Somanath said in Thiruvananthapuram on Saturday that the spacecraft had been integrated with the launch vehicle at Sriharikota. Once launched, it will take 125 days to travel to its destination at L1.

On board the Chandrayaan-3 mission’s Vikram lander which soft-landed on the moon on August 23, the SPL had two payloads; the Chandra’s Surface Thermophysical Experiment (ChaSTE) and the Radio Anatomy of Moon Bound Hypersensitive Ionosphere and Atmosphere (RAMBHA).