How Shubhanshu Shukla survived blazing heat during return to Earth
What's the story
SpaceX's Crew Dragon spacecraft, carrying the Axiom-4 mission crew, successfully landed in the Pacific Ocean off San Diego, California yesterday. The landing was a success despite the vehicle's charred exterior. Upon re-entry into Earth's atmosphere, the spacecraft was subjected to extreme temperatures of 1,600-2,000 degree Celsius. This intense heat generated a fire that could have been fatal for the passengers, including Shubhanshu Shukla. So, how did they survive? Let's find out.
Technological resilience
Re-entry into atmosphere generates intense heat
The Crew Dragon spacecraft, with its cutting-edge tech, survived these extreme conditions. As it re-entered Earth's atmosphere from space at a speed of some 27,000km/h, the craft collided with upper atmospheric layers creating friction. This friction led to atmospheric molecules colliding with the spacecraft and generating intense heat that caused fire. The outer surface temperature reached up to 2,000 degree Celsius but the craft survived due to its advanced heat-resistant technology.
Shield technology
Heat shield absorbs and burns away the heat
To combat extreme temperatures, Crew Dragon was fitted with a special heat shield called PICA-X (Phenolic Impregnated Carbon Ablator). This material absorbed and burnt away under extreme heat, gradually shedding its surface to keep the internal temperature suitable for humans. When the spacecraft landed on Earth, its outer surface looked burnt in several areas.
Descent strategy
De-orbit burn and parachute deployment
To avoid excessive heat build-up during re-entry, a de-orbit burn was performed to lower the capsule's speed. Onboard thrusters controlled the spacecraft's velocity, ensuring it entered Earth's atmosphere at the right angle and speed to minimize friction-induced heat. As the capsule descended into lower layers of atmosphere, heat started to dissipate. At this stage, four parachutes deployed to slow down the spacecraft and prepare it for safe splashdown in Pacific Ocean.
Safety measures
A look inside the capsule
The PICA-X heat shield and multilayer insulation kept internal temperature between 25-30 degree Celsius, ensuring a safe environment for astronauts. As the heat shield burnt, it gradually shed its outer surface to release heat. Underneath it, a layered thermal insulation system blocked remaining heat from penetrating the capsule. Astronauts inside remained unaffected by extreme conditions outside. After landing, the spacecraft was thoroughly inspected to determine which parts are reusable in line with SpaceX's push for more sustainable space travel.