Gaganyaan: The importance of Crew module Re-entry Experiment
New Delhi, Feb 1: A manned space mission is very different from all other missions that ISRO has so far completed. And it is for this reason that Gaganyaan is truly challenging.
If ISRO executes Gaganyan perfectly, then there would be a paradigm shift in the way the world looks at India's capabilities in terms of space exploration. The success of Gaganyan can prove India's ability to develop complex technologies and would establish ISRO as a major space power.
For a manned mission, the key distinguishing capabilities that ISRO has to develop include the ability to bring the spacecraft back to Earth after the flight, and to build a spacecraft in which astronauts can live in Earth-like conditions in space. All the missions so far, including the Mars and the Moon missions, did not involve bringing back the spacecraft into earth's atmosphere. Here, not does the module needs to be brought, it has to be brought back safely as there would be humans in it.
Crew Module Atmospheric Re-entry Experiment:
The Crew Module Atmospheric Re-entry Experiment (CARE) is an experimental test vehicle for the Indian Space Research Organisation's future ISRO orbital vehicle called Gaganyaan. It was launched successfully on 18 December 2014 from the Second Launch Pad of the Satish Dhawan Space Centre, by a GSLV Mk III designated by ISRO as the LVM 3X CARE mission.
The crew module was mounted upside-down inside the payload fairing of the GSLV Mk III. CARE was made of aluminium alloy and had a lift-off mass of 3,735 kg. Its diameter was 3100 mm and its height was 2698 mm. The module had an ablative thermal protection. The side panels were covered with Medium Density Ablative (MDA) tiles and the forward heat shield was made of carbon phenolic tiles. It was powered by batteries and was equipped with six liquid-propellant (MMH/MON3) 100 N thrusters.
CARE splashed down into the Bay of Bengal about 600 km from Port Blair in the Andaman Islands and about 1600 km from the Sriharikota launch site. This experiment was carried out to test the re-entry capability of the spacecraft that would bring the Gaganyaan crew back to earth.
Challenges with Re-entry:
When a spacecraft re-enters earth's atmosphere, it would have to withstand high temperatures, thousands of degrees, due to friction with the air. Even when a meteorite enters the earth, the earth's gravity speeds up its descent and this causes friction with the air. This friction increases the temperature so much that most of the meteorites just vapourise before reaching the earth's surface. This is the reason we see shooting stars.
The spacecraft's re-entry into the atmosphere also has to be very precise both in terms of speed and angle, and even the slightest deviation could end in disaster.