What would you do if you were sent to space for an eight-day mission and you end up getting stuck there for nine months? Most of us would panic. But Sunita Williams and Butch Wilmore are not most of us. Maintaining their cool for longer than most of us, Williams and Wilmore have finally begun their long-awaited journey back to home. Their SpaceX Dragon spacecraft detached from the ISS at 10:35 am IST and the duo will make a splashdown in Florida around 3:27 am IST on Wednesday.

But before they get out of their space suits, they’ll endure an intense reentry phase where “if you look out the spacecraft’s window…the only view would be a wall of fire”. “For reentry into Earth’s atmosphere, spacecraft must withstand temperatures up to 7,000 degrees Fahrenheit, caused by the compression of gas and air particles against the surface of the spacecraft. They must also be engineered to fly at hypersonic speeds and ultimately undergo an enormous slowdown for safe landing,” NASA explained in a blog post.

They overcome this through the Heatshield for Extreme Entry Environment Technology (HEEET) developed by the space agency’s Ames Research Center. Think of it like a cosmic suit of armor, designed to shield spacecraft from the intense heat generated during atmospheric entry. Crafted from a dual-layer, three-dimensional woven material, HEEET offers a cutting-edge defense against the fiery forces of reentry. Not only does it withstand extreme temperatures, but it also reduces entry loads and slashes heat shield mass by up to 40%, NASA explained.

By using heat shields, parachutes and advanced software, NASA engineers create innovative solutions to help spacecraft endure the intense conditions of atmospheric reentry. As Williams and Wilmore brace for their fiery descent, it’s comforting to know that decades of NASA’s heat-shielding genius has their backs.