The voyage home
ESA astronaut Samantha Cristoforetti, Russian commander Anton Shkaplerov and NASA astronaut Terry Virts returned to their Soyuz TMA-15M spacecraft and lifeboat at the end of their 200-day mission on the International Space Station. The ride home was even shorter than the ride to the International Space Station, taking less than four hours from undocking to landing in the steppes of Kazakhstan.
Shortly after undocking, Soyuz separates into three parts. The orbital and service modules burn up on reentry in the denser layers of Earth’s atmosphere. The descent module turns to position its heatshield towards the direction of reentry, so that it can handle the 1600°C created by the friction with our atmosphere.
Reentry starts at an altitude of about 120 km, when their cruising speed of 28 800 km/h is reduced dramatically and the crew are pushed back into their seats with a force of 4–5 g. This is equivalent to four to five times their own body weight.
Parachutes deploy to decrease speed even more and the astronauts sit in custom-fitted seats that absorb the shock of impact with our planet even further. At the last moment, retrorockets fire before touchdown to limit the speed of impact to around 5 km/h.
After landing, the crew deploy a communication antenna, so that the rescue teams can pinpoint them, but generally search and rescue teams are already onsite to retrieve the space voyagers.
The spacecraft is cramped and astronauts return to Earth in a weakened state, so pulling the crew out of their capsule one by one can take some time.
Soyuz leaves the Station
00:00 separation command
Separation command to begin opening the hooks and latches that hold Soyuz on the Station docking port
+00:03 separation from Station
Hooks opened. Soyuz begins physical separation from the docking compartment at 0.1 m/s
+00:06 separation burn from Station
A 15-second separation burn when the Soyuz is about 20 m from the Station
+02:29 deorbit burn
When Soyuz is about 19 km from the Station, the engines fire for almost five minutes
+02:57 separation of modules
The unoccupied Orbital Module separates from the Descent Module and burns up on reentry
+03:00 Entry Interface
The Soyuz reaches Entry Interface at 122 km altitude
+03:08 parachutes open
Parachutes are deployed:
1. Two pilots
2. Drogue slows the descent from 230 m/s to 80 m/s
3. Main slows the Soyuz to 7.2 m/s. The Soyuz descends at an angle of 30º to cool, then the main parachute shifts it to a straight vertical descent
+03:22 soft landing engine firing
Six soft-landing engines fire to slow the vehicle’s descent rate to 1.5 m/s just 1 m above the ground
Soyuz lands on Earth