Astronauts Scott Kelly and Mikhail Kornienko successfully returned to Earth today (Mar. 2) after spending nearly a year in space. In the process, Kelly has set the record for having spent the longest time in space for an American. Aboard the International Space Station (ISS), Kelly orbited the Earth 5,000 times and traveled more than 100 million miles.
But it is the last 20 minutes of the mission—cramped with fellow astronauts in the Soyuz spacecraft hurtling back to Earth—that he considers the most exhilarating. “It’s so much fun for me that … if I’d hated being in space … I’d have done it all over again just for that last 20 minutes in the Soyuz,” Kelly said before he began his year-long mission, his fourth trip into space and back.
This is the sequence of events that Kelly considers “so much fun” (with help from Eric Berger of Ars Technica, who calls it the best ride in the galaxy):
- The landing sequence begins when the Soyuz capsule is 12 kilometers (7.5 miles) away from the ISS and at an altitude of 425 kilometers above the Earth. (Some call what follows the four longest minutes of their lives, because a lot of things can go wrong.)
- Next, the Soyuz fires its rockets to push itself out of orbit. This is when the astronauts start falling back to Earth.
- “As soon as you do the de-orbit burn things start to pick up,” astronaut Kjell Lindgren, who returned to Earth in 2015, told Ars Technica. “The onset of G forces is almost imperceptible, but you notice the dust start to settle in the vehicle. Then it’s fireball time. First you see an orange haze out of the window and then big chunks of fiery debris from the spacecraft come streaking by the window. It’s pretty amazing to watch, really.”
- The orbital and descent modules of Soyuz separate at about 140 kilometers above the Earth, and then the astronauts enter the upper atmosphere.
- During this period, the astronauts experience maximum gravitational force, about 4.4 times that on Earth. Remember that before this, Kelly had lived in near zero-gravity for a year.
- At about 30 kilometers above Earth, the astronauts exit the plasma phase, when the Soyuz reaches its maximum temperature because of friction from Earth’s atmosphere.
- At about 15 kilometers above the Earth, there is a massive jolt generated by the opening of the rocket’s parachute. That slows the Soyuz from a speed of about 230 meters/second to 80 meters/second (from 515 to 180 miles per hour).
- “You hear this rush of air and then you feel the opening shock,” Lindgren told Ars Technica. “You go almost head over heels as the capsule twists around under that drogue chute. That’s an amazing experience, too. Tremendous fun. Twisting and flailing around. That sensation of rolling around also gives you a huge relief, because it signals the parachute has opened. Then the main chute comes out and things really settle down.”
Only a handful of people have experienced this joyous ride. “People who have flown in it previously will try to prepare you for it, but I think nothing really can until you’ve actually been there yourself and experienced it. It’s definitely an eye opener,” Kelly said.
Doctors will perform tests on Kelly and Kornienko soon after their landing. They are what one NASA administrator calls “living, breathing, walking medical specimens.” In the case of Kelly, doctors will be able to test the effects of space by comparing his body with his twin brother’s, who spent the past year on Earth.
Although he has already set records, in a press conference beamed from the space station before his departure, Kelly figured he was fit to spend another year in space. “Going to Mars and having people stay in space for much longer than we have before, is clearly doable,” he said.