Compared to rockets, re-entering modules have a unique and unforgiving set of challenges

| Photo Credit: PTI

The atmospheric phase of all space missions is challenging for both ascending rockets and descending space capsules.As the rocket lifts off from the earth and heads towards its orbit, it accelerates slowly through the atmosphere to keep the mechanical loads on the vehicle to a minimum. When a space capsule, like the Gaganyaan crew module, re-enters from its orbit around the earth, it will hit the atmosphere at a blistering speed of 7,500-8,000 m/s. More than 99% of this kinetic energy will be dissipated into the atmosphere as heat energy. However, a small portion directed back towards the module will still be intense enough to melt it if it is not protected by a robust thermal protection system (TPS). Published - August 21, 2026 08:30 am IST