UPSC Darpan

Science & TechnologyGS322 September 2026

Gaganyaan Crew Module to Land on Two Drogues and Three Main Parachutes Built by ADRDE

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The news

New Delhi / Thiruvananthapuram. In an explainer in The Hindu, Unnikrishnan Nair S. — former director of the Vikram Sarabhai Space Centre (VSSC) and the Indian Institute of Space Science and Technology, and founding director of ISRO’s Human Space Flight Centre — sets out how the Gaganyaan crew module, the capsule in which Indian astronauts will ride, will slow down for a safe landing. Any spacecraft re-entering the atmosphere loses much of its velocity through atmospheric drag, but parachutes are needed for a gentle touchdown on land or sea. The system uses three kinds of chute: a pilot chute, a small parachute that pulls out the bigger ones; a drogue chute, deployed early to stabilise the module and cut its speed; and the main chute, with a wide canopy, for the final phase. Because the blunt module leaves a turbulent wake, chutes must be ejected through it quickly, and are generally deployed below the speed of sound. In the lower atmosphere the module will be moving at around 170 m/s, and opening the full main parachute at once would cause a high “opening shock” that could shred the fabric or subject the crew to dangerous deceleration. Staging increases chute diameter in steps, and “reefing” — a cord wound around the canopy, cut by a timed cutter after a preset delay — stops a chute from opening too fast. The Gaganyaan crew module has two drogue chutes deployed by mortars and three main chutes deployed by mortar-ejected pilot chutes; if one main parachute fails, the remaining two are fully capable of a safe touchdown. The developing agency is the Aerial Delivery Research and Development Establishment (ADRDE), Agra, a DRDO laboratory. Testing uses the rail track rocket sled (RTRS) at the Terminal Ballistic Research Laboratory, Chandigarh, drops from helicopters or aircraft, and small rocket-powered test vehicles. After splashdown, pyro cutters detach the canopy so that wind does not drag or capsize the module; Kevlar, Nomex and nylon are the main materials. ISRO’s website records that it carried out the first Integrated Air Drop Test (IADT-01) on 24 August 2025 at Sriharikota, dropping a simulated crew module of about 4.8 tonnes from about 3 km from an Indian Air Force Chinook helicopter, with ten parachutes of four types and a final descent velocity of about 8 m/s. The syllabus link is space technology, indigenisation and human spaceflight.

The chain in one line: India announces a human spaceflight programme and sets up ISRO’s Human Space Flight Centre → crew safety demands redundant recovery systems that no foreign partner supplies off the shelf → DRDO’s ADRDE develops a staged pilot–drogue–main parachute system with reefing → ISRO completes the first Integrated Air Drop Test in August 2025 and continues sled and drop testing → the system must prove it can survive a single main-chute failure before a crewed flight

Static syllabus linkage

  1. Gaganyaan is India’s route to independent human spaceflight. The Gaganyaan programme aims to demonstrate India’s capability to send a crew of astronauts to low earth orbit, at about 400 km, and bring them back safely to a sea landing. It uses a human-rated version of the LVM3 launch vehicle, a crew module for the astronauts and a service module for propulsion and power, and is preceded by uncrewed flights and test-vehicle missions. The first test-vehicle flight, TV-D1, in October 2023, tested the crew escape system that pulls the capsule away from a failing rocket. The programme is led by ISRO’s Human Space Flight Centre in Bengaluru, with DRDO laboratories supplying life-support, recovery and safety systems.
  2. Re-entry is mainly a problem of drag and heat. A capsule returning from orbit travels at several kilometres per second, and most of that speed is shed through atmospheric drag, which converts kinetic energy into heat absorbed by a heat shield. A blunt body shape increases drag and pushes the shock wave away from the surface, reducing heating, which is why crew capsules are blunt rather than streamlined. Parachutes operate only in the last phase, once the vehicle is subsonic. The dynamic pressure on a parachute depends on air density and the square of velocity, so opening a large chute too early creates forces that can destroy it.
  3. Redundancy is the principle of crewed-system design. Human-rated systems are designed so that no single failure can cause loss of the crew, a principle often called single-fault tolerance. In recovery systems this means clusters of parachutes, each with an independent deployment chain, so that the loss of one still allows a safe descent. The same principle governs the crew escape system and life support. It is why crewed programmes spend years on tests that uncrewed satellite missions do not need.
  4. DRDO laboratories are part of India’s space ecosystem. The Defence Research and Development Organisation, formed in 1958 and working under the Department of Defence Research and Development of the Ministry of Defence, runs a network of laboratories. The Aerial Delivery Research and Development Establishment at Agra develops parachute and aerial delivery systems, and the Terminal Ballistics Research Laboratory at Chandigarh operates test facilities including a rail track rocket sled. Cooperation between ISRO, a civilian agency under the Department of Space, and DRDO shows how dual-use technologies are shared across India’s strategic establishment.

Why UPSC loves this

  1. Space technology is a GS3 fixture. The GS3 syllabus names awareness in the fields of space and indigenisation of technology. Mains has asked about India’s space programme and its benefits, and Prelims regularly tests missions, launch vehicles and the organisations behind them. Gaganyaan components, test flights and the agencies involved are frequent targets.
  2. Explainers like this are where Prelims statements come from. The examiner likes mechanism-based statements: the order of parachute deployment, the purpose of reefing, why deployment is subsonic, and which laboratory develops what. Learning the mechanism once protects against several tricky statement combinations.

Prelims nuggets

  • The Gaganyaan crew module parachute system uses pilot, drogue and main parachutes, with drogues deployed early to stabilise and slow the module.
  • The Gaganyaan crew module has two drogue parachutes deployed by mortars and three main parachutes deployed by mortar-ejected pilot chutes.
  • The Aerial Delivery Research and Development Establishment at Agra, a DRDO laboratory, is the developing agency for the Gaganyaan parachute system.
  • A rail track rocket sled facility for parachute testing is located at the Terminal Ballistics Research Laboratory, Chandigarh.
  • Reefing is a technique in which a cord around a parachute canopy restricts its opening until a timed cutter releases it.
  • ISRO conducted the first Integrated Air Drop Test (IADT-01) for Gaganyaan at Sriharikota in August 2025 using an Indian Air Force Chinook helicopter.
  • Crew-module parachutes are generally deployed only after the capsule has slowed below the speed of sound, because dynamic pressure on the canopy rises with the square of velocity.

Analysis

  1. The parachute is where a crewed programme is most unforgiving. A launch failure can be survived through the escape system, but a recovery failure at the end of a successful mission has no backup other than the remaining chutes. That is why the design tolerates the loss of one of three main chutes and why so much testing — sleds, air drops, rocket-powered test vehicles — goes into a system that works only for a few minutes. The time the programme is taking should be read in this light. Delay in crewed spaceflight is often a sign of caution rather than incompetence.
  2. Indigenous recovery systems are a strategic asset, not just a technical milestone. Few countries have developed crew-rated parachute systems, and those that have do not sell them freely. By having a DRDO laboratory build the system and a DRDO facility test it, India acquires knowledge that also serves military airdrop, payload recovery and future reusable systems. The counter-view is that buying proven components could save time. But a crewed programme that depends on imported safety-critical systems is exposed to export controls at exactly the moment it matters.
  3. Materials science is the hidden bottleneck. Kevlar, Nomex and aerospace nylon are specialised polymers, and the explainer notes that parachute performance depends on tensile strength, heat resistance and mass. Whether India produces these materials domestically at aerospace grade is a question the article does not answer, and it matters for self-reliance. A programme can be indigenous in design and still import its fibres. Building domestic capacity in advanced materials is one of the less visible tasks of Atmanirbhar Bharat in space.
  4. Testing infrastructure outlives the mission. Facilities such as the rocket sled at Chandigarh and the integrated air-drop test capability are assets that future missions — a space station module, cargo return capsules, planetary landers — will reuse. Public spending on test infrastructure is therefore an investment in a pipeline, not a one-off cost. The private space sector opened up since 2020 will also need such facilities, and access to them on fair terms can help Indian start-ups.

Possible Mains question

“In human spaceflight, the most critical systems are the ones that operate for only a few minutes.” Discuss with reference to the recovery system of the Gaganyaan crew module, and examine how indigenous development of such systems contributes to India’s strategic autonomy in space. (15 marks, 250 words)

Model approach

  1. Introduction. Introduce Gaganyaan as India’s crewed mission to low earth orbit and state that a safe return depends on a staged parachute system after atmospheric drag has removed most of the capsule’s speed.
  2. Body — how the system works. Explain pilot, drogue and main chutes, deployment through the wake below the speed of sound, staging and reefing to limit opening shock at about 170 m/s, the two-drogue and three-main configuration, and redundancy against a single main-chute failure.
  3. Body — testing and development. Describe the RTRS at TBRL Chandigarh, helicopter and aircraft drops including IADT-01 in August 2025, rocket-powered test vehicles, and ADRDE Agra’s role; mention materials such as Kevlar, Nomex and nylon.
  4. Body — strategic autonomy. Argue that indigenous safety-critical systems reduce exposure to export controls, create dual-use capabilities for defence airdrop and future reusable systems, and build test infrastructure for a space station and private space firms; note the remaining dependence on advanced materials.
  5. Conclusion. Conclude that crew safety is the measure of a spacefaring nation and that patient, indigenous testing is the price of independence in human spaceflight.

Administrator's brainstorm

As a mission director, you are under pressure to announce a crewed launch date, but one parachute test has shown an anomaly. What do you do?

Crew safety must override schedule pressure, so I would not announce a date until the anomaly is understood and a corrective test succeeds. I would convene a failure analysis board, share its findings with the programme’s review committees and communicate honestly to the public that testing is continuing. The history of human spaceflight shows that disasters often follow when warnings are overridden to meet a date. A short delay costs prestige; a failure costs lives and the programme.

A private start-up asks to use the DRDO rocket sled facility for its own payload recovery system. How should the government respond?

Opening public test facilities to private firms on transparent terms supports the space sector reforms and avoids costly duplication. Access should be granted through a published fee structure and scheduling system, with priority for national missions and appropriate security safeguards for a defence facility. IN-SPACe, the authorisation body for private space activities, can act as the interface. This turns a sunk public investment into a platform for the wider ecosystem.

An interview board asks: is human spaceflight worth the cost for a developing country?

Human spaceflight drives technologies in life support, materials, medicine and safety engineering that have wide uses, and it builds institutional capability that satellites alone do not. It also gives a country a seat when norms for space stations and lunar activity are being written. The cost must be weighed against other priorities, but India’s programme is modest by global standards and builds on existing launch capacity. The strongest case is that the capacity to go and return safely is a form of sovereignty that cannot be bought later.