Sci-Tech · 22 Aug 2026

Gaganyaan ablative thermal protection system

Why has ISRO chosen an ablative thermal protection system, rather than a radiative one, for the Gaganyaan crew module's re-entry?

AAblative materials are reusable across multiple missions, reducing manufacturing costs over successive flights
BAblative materials shed mass unevenly to dissipate heat, tolerating fluctuating thermal loads better than radiative systems, which are less forgiving of design or manufacturing imperfections
CAblative materials are lighter than radiative shields, which directly reduces the crew module's re-entry velocity
DAblative systems allow the mission to be aborted mid-descent if re-entry temperatures exceed safe limits
This question is based on: Why ISRO Chose a Heat Shield That's Designed to Destroy Itself
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About this question

Why in news

With Gaganyaan's first uncrewed test flight approaching, ISRO has detailed how the crew module's ablative thermal protection system will shield astronauts from re-entry temperatures of up to 1,800°C, a critical safety system with zero margin for error since descent cannot be aborted mid-flight.

Why for UPSC

UPSC Sci-Tech questions typically probe the engineering rationale behind a design choice rather than the headline temperature figure - this question tests whether the aspirant understands why ablative technology suits an unabortable, high-risk re-entry phase.

Prelims summary

Gaganyaan's ablative thermal protection system sheds material to manage uneven re-entry heat (up to 1,800°C exterior, kept below 150°C inside), a single-use but fail-safe design validated earlier through the 2007 Space Capsule Recovery Experiment and the 2014 CARE mission.

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