How Will Gaganyaan’s Crew Module Deploy Its Parachutes?

ISRO is testing the parachute-based deceleration and recovery system of the Gaganyaan crew module, which is crucial for ensuring a safe landing after atmospheric re-entry.Gaganyaan uses a redundant multi-stage parachute system to progressively reduce the crew module’s speed before splashdown.

How Are Parachutes Deployed?

• The crew module uses three types of parachutes — pilot, drogue and main parachutes.
• Pilot chutes are small parachutes used to pull out the larger drogue or main parachutes.
• Drogue chutes deploy first to stabilise the module and reduce its velocity.
• Main parachutes deploy in the final phase to bring the module to a safe landing speed.
• Mortar-based ejection systems help parachutes cross the turbulent wake behind the blunt-shaped crew module.

Why Are Parachutes Deployed in Stages?

• During descent, the crew module may still be travelling at around 170 m/s in the lower atmosphere.
• Deploying a full-size parachute immediately would create a severe opening shock and dangerous deceleration.
• Multi-stage deployment gradually increases parachute area and keeps aerodynamic loads within safe limits.
• Reefing cords initially restrict parachute opening and are later cut to allow full canopy inflation.

How Are Parachutes Tested?

• Parachutes are tested using rail-track rocket sleds, where test articles are accelerated before deployment.
• Additional testing involves releasing test modules from aircraft or helicopters.
• Small rocket-powered test vehicles are also used to simulate deployment at required altitudes and velocities.
• DRDO’s Terminal Ballistics Research Laboratory (TBRL), Chandigarh, has facilities for rocket-sled testing.

What Materials Are Used?

• Kevlar is used in high-load suspension lines and reinforcement because of its high tensile strength.
• Nomex is used in heat-exposed areas because of its thermal and flame resistance.
• Nylon is widely used for parachute canopies due to its elasticity, strength and compact packing ability.

Parachute System in Gaganyaan

• The Gaganyaan crew module carries two drogue parachutes and three main parachutes, along with pilot parachutes.
• The system is designed with redundancy, so failure of one main parachute does not compromise safe recovery.
• The remaining two main parachutes are sufficient to ensure a safe touchdown/splashdown.
• ADRDE, Agra, under DRDO, is the principal agency developing Gaganyaan’s parachute recovery system.

Gaganyaan’s parachute system combines multi-stage deployment, redundancy, specialised materials and extensive testing to safely decelerate and recover the crew module after re-entry.