From UPSC perspective, the following things are important :
Prelims level : Inflatable Aerodynamic Decelerator (IAD)
Mains level : Not Much
The Indian Space Research Organisation (ISRO) has successfully tested a technology that could aid the cost-effective recovery of spent rocket stages and safely land payloads on other planets.
What is IAD?
- IAD is a technique used for an atmospheric entry payload.
- An inflatable envelope and an inflatant (anything that inflates the envelope, like air or helium) make up the inflatable aerodynamic decelerator.
- While entering the atmosphere, it inflates like a balloon and decelerates the lander.
- The inflatant is designed to fill the inflatable envelope to a condition such that it surrounds the payload meant to enter the atmosphere of a planet or satellite and causes aerodynamic forces to slow it down.
- In simpler words, IAD is designed to increase drag upon entering the atmosphere of any planetary body, like Earth, Mars, or even Moon.
- Its shape is maintained by a closed, gas-pressured body and the inflatant gas is also generated internally. Some versions also use ram air or both.
How significant is this IAD?
- Some space agencies, including NASA, have already successfully tested advanced versions of the technology, including the supersonic and hypersonic variants.
- However, for near future missions of ISRO, the current version that it tested is perfect.
- Its use was first proposed by NASA more than 50 years ago for planetary entries.
Minuscule of ISRO’s IAD
- The IAD tested by ISRO was inflated at an altitude of around 84 km and the sounding rocket’s cargo dropped through the atmosphere on it.
- It is fitted with a booster motor. It also has a spin rocket that is ejectable.
- The inflatable structure is made out of Kevlar fabric, which is a very strong synthetic fibre and also heat resistant to withstand atmospheric pressure and temperature changes.
- On top of it, it’s coated with polychloroprene, an oil and wax resistant rubber, to withstand extreme temperatures.
- In the inflation system, it uses compressed nitrogen stored in a bottle.
- It has consistently decreased the payload’s velocity through aerodynamic drag while maintaining the expected trajectory during the test flight.
Where does ISRO intend to use it?
- The IAD will help ISRO in performing many space tasks effectively including recovery of spent stages of rockets, for landing payloads on missions to other planetary bodies.
- This is the first instance where an IAD has been specially created for spent stage recovery.
- So inter-planetary missions are certainly one aspect that ISRO wishes to explore.