HUMAN SPACEFLIGHT: SCIENCE & TECHNOLOGY

HUMAN SPACEFLIGHT: SCIENCE & TECHNOLOGY

NEWS: How is spaceflight safety ensured?

WHAT’S IN THE NEWS?

Gaganyaan is ISRO’s first human spaceflight mission focused on demonstrating safe crewed space travel using globally tested safety protocols. It includes advanced systems for launch escape, in-orbit control, and reentry, adapted for Indian conditions.

Overview of Gaganyaan Mission

  • The Gaganyaan mission is India’s first indigenous human spaceflight program led by ISRO (Indian Space Research Organisation).
  • It aims to demonstrate India’s capability to send humans into space and bring them back safely.
  • The mission will not dock with any space station but will simulate human spaceflight using international safety protocols and practices.
  • The focus is on testing and validating the full cycle of crewed spaceflight—from launch to orbit, and reentry to recovery.

Understanding Human Spaceflight

  • Human spaceflight refers to the act of sending humans beyond Earth’s atmosphere, primarily into Low Earth Orbit (LEO), to the Moon, or to planets like Mars.
  • Such missions require life-support systems, safety mechanisms, and crew training to ensure survival in hostile space environments.
  • India will be joining an elite group of countries (USA, Russia, China) that have achieved independent human spaceflight capability.

 

Three Main Stages of Human Spaceflight
Launch Phase

  • This phase starts with the ignition of the rocket and ascent through Earth’s atmosphere.
  • It involves high mechanical stress, sound levels, and rapid acceleration.
  • Critical safety mechanisms are integrated, such as the Crew Escape System, to save the astronauts in case of a launch failure.

Orbital Phase

  • After reaching orbit, the spacecraft must stabilize itself and begin orbital operations such as trajectory control, system checks, and life support monitoring.
  • Even though Gaganyaan won’t dock with another spacecraft, its crew is being trained in international docking procedures for future missions.

Reentry and Landing Phase

  • After completing the orbital duration, the spacecraft fires thrusters to de-orbit and begin its return.
  • This stage involves intense heat due to atmospheric friction, requiring thermal shielding.
  • Controlled descent is managed using a complex parachute system to ensure a soft landing—expected to occur in the Arabian Sea or Bay of Bengal.

Historical Accidents and Importance of Safety

  • Human spaceflight has witnessed fatal accidents, underlining the importance of fail-safe mechanisms.
  • Apollo-1 (1967): A fire during a ground test killed three NASA astronauts due to oxygen-rich cabin and faulty wiring.
  • Soyuz T-10 (1983): A launchpad fire was survived thanks to rapid escape system activation.
  • Challenger Disaster (1986): The shuttle broke apart 73 seconds into flight due to an O-ring failure in a booster.
  • Blue Origin NS-23 (2022): Demonstrated a successful escape system during a mid-flight engine failure, saving the capsule.
  • NASA’s ISS Return (2025): Highlighted modern reentry and splashdown procedures, showcasing improvements in astronaut recovery systems.

ISRO’s Human Spaceflight Safety Measures
Launchpad Safety Enhancements

  • Post-Apollo safety learnings prompted ISRO to build new escape infrastructure at Sriharikota.
  • The launch pad is equipped with ziplines and fireproof elevator systems to allow fast evacuation of astronauts if an incident occurs before launch.

Crew Escape System (CES)

  • ISRO’s Gaganyaan uses a tractor-type escape tower mounted above the crew module.
  • It has two major motors:
  • Low-altitude Escape Motor (LEM) for pad and early flight aborts.
  • High-altitude Escape Motor (HEM) for aborts in higher atmosphere stages.
  • A pad abort system can rapidly eject the crew capsule from the rocket seconds after ignition if instability is detected.

In-Orbit Emergency Systems and Docking Training

  • The Gaganyaan spacecraft comprises two segments:
  • Crew Module (CM): Accommodates astronauts and controls life-support.
  • Service Module (SM): Contains propulsion, power, and navigation systems.
  • In case of in-orbit malfunction, the CM can detach and use its propulsion to re-enter Earth’s atmosphere.
  • Even though the mission won’t dock, ISRO is training astronauts in global docking protocols for compatibility with ISS-type stations or future Indian space stations.
  • For reference, the International Space Station (ISS) always maintains emergency “lifeboat” spacecraft like Soyuz or Crew Dragon for astronaut evacuation.

Reentry and Landing Protocols

  • Reentry starts with retro-thrusters firing to lower the spacecraft’s velocity and guide it toward Earth’s atmosphere.
  • A robust thermal protection system safeguards the crew from frictional heating that can reach up to 1,800°C.
  • The parachute system has a multi-step deployment process for safety and stability:
  • Apex separation parachutes are first deployed at ~15.3 km altitude to stabilize the module.
  • Drogue chutes then slow the descent and orient the capsule correctly.
  • Pilot chutes extract the final set of three main parachutes, reducing descent speed to 10–12 m/s.
  • Upon splashdown, pyrotechnic mechanisms release the parachutes automatically to avoid drag in water.

ISRO’s Broader Strategy and Significance of Gaganyaan

  • ISRO is mirroring best international practices while adapting to Indian geography, logistics, and scientific expertise.
  • The mission is structured to incrementally build and validate all subsystems: from astronaut training and ground support to life-support modules and capsule recovery.
  • Gaganyaan is a stepping stone to larger goals, such as building a permanent space station, deep-space missions, and planetary exploration.

Conclusion

  • The Gaganyaan mission is not just about sending humans to space—it is about building a robust, indigenous space ecosystem for human-rated missions.
  • ISRO’s focus on safety across all phases—launch, orbit, and landing—reflects maturity in space engineering.
  • Through Gaganyaan, India moves closer to achieving self-reliant, safe, and sophisticated human spaceflight capability on the global stage.

 

Source: https://www.thehindu.com/sci-tech/science/how-is-spaceflight-safety-ensured/article69449173.ece#:~:text=Before%20and%20during%20launch&text=After%20ignition%20until%20orbital%20insertion,the%20rocket%20has%20lifted%20off.