Soyuz MS-02 trio returns to Earth
Three International Space Station (ISS) crew members returned to Earth in their Soyuz MS-02 spacecraft on April 10, 2017, after nearly six months aboard the outpost.
Russian cosmonauts Sergey Ryzhikov and Andrey Borisenko, and NASA astronaut Shane Kimbrough landed at about 7:20 a.m. EDT (5:20 p.m. local time / 11:20 GMT) on the Steppe of Kazakh about 92 miles (148 kilometers) southeast of Dzhezkazgan, Kazakhstan.
The three crew members boarded their Soyuz about six hours before landing. The hatch between the spacecraft and the Poisk docking module was shut and sealed at 12:45 a.m. EDT (04:45 GMT). This came minutes after the trio said farewell to the other half of the station crew – newly appointed commander and NASA astronaut Peggy Whitson, and Flight Engineers Oleg Novitskiy of Roscosmos and Thomas Pesquet of the European Space Agency. Novitskiy and Pesquet will land in Soyuz MS-03 in June 2017, while Whitson will remain on the outpost until September 2017 to land with the two person crew of Soyuz MS-04.
For the next few hours, the Soyuz crew depressurized the vestibule – the space between the hatches of the two spacecraft – and conducted leak checks, put on their Sokol launch and entry suits, and strapped themselves into their seats. Undocking occurred at 3:57 a.m. EDT (07:57 GMT). It was at that moment that Expedition 50 became Expedition 51 for the trio remaining on the outpost.
The undocking ended the trio’s 171-day stay aboard the outpost. Four springs in the docking assembly pushed the two spacecraft apart at an initial opening rate of 4.7 inches (12 centimeters) per second.
After three minutes coasting away from the station, the thrusters on the Soyuz fired for eight seconds to accelerate the vehicle’s departure to 19.7 inches (50 centimeters) per second.
A second departure burn occurred about 90 seconds later. This 15-second burn pushed the accelerated the spacecraft to 4.9 feet (1.5 meters) per second and set it up on the proper trajectory away from the station.
Some three-and-a-half hours later, after moving about 7.5 miles (12 kilometers) away from the ISS, the crew commanded the Soyuz’s SKD main engine to ignite and burn retrograde for about 4 minutes, 38 seconds. This slowed the spacecraft down by 420 feet (128 meters) per second, enough for the low point of the vehicle’s orbit to dip into the atmosphere for re-entry. This was completed at 6:34 EDT (10:34 GMT) while 249 miles (400 kilometers) above the Atlantic Ocean.
Soyuz’ three modules – the Orbital Module, Descent Module and Service Module – separated about 20 minutes later. Only the Descent Module returns to Earth intact. The other two burn up in the atmosphere.
Entry interface occurred just before 7 a.m. EDT (11:00 GMT). At that time the Soyuz was traveling about 4.7 miles (7.6 kilometers) per second at an altitude of 327,000 feet (about 100,000 meters).
Heat began to build up around the spacecraft as the friction of the atmosphere started slowing the Soyuz down. Protected by a heat shield, the temperature around the vehicle built up to about 2,900 degrees Fahrenheit (1,600 degrees Celsius). The vehicle slowed down rapidly, causing the crew to feel a force some four to five times that of Earth’s gravity.
“We have 4.2 G’s now and we are feeling good,” Ryzhikov said during descent to Mission Control in Moscow.
At 7:07 a.m. EDT (11:07 GMT), a series of parachutes began to open. While the Soyuz was traveling 702 feet (214 meters) per second, a pair of drogue chutes deployed. That was followed by the main parachute once the vehicle descended passed 4.7 miles (7.5 kilometers) in altitude.
Once the spacecraft descended past the 3.4-mile (5.5-kilometer) mark, the Soyuz jettisoned its heat shield, exposing the soft landing engines.
When the spacecraft reached three feet (about 1 meter) off the ground, the soft landing engines ignited momentarily to cushion the landing for the crew. Meanwhile, the couches on which the crew were sitting on moved up in order to absorb the shock of landing. Previous Soyuz-flyers have described the landing as going through a car crash.
Upon impact, the capsule began to tumble end-over-end as the parachute dragged it momentarily across the ground, something that sometimes happens during Soyuz landings.
Ultimately, the spacecraft ended up on its side before the parachute was cut as planned.
Seconds after landing, search and recovery teams made their way to the capsule to begin safing the Soyuz and extracting the crew.
Once the top hatch was opened, ground teams began pulling the crew out. First was Ryzhikov, as he was in the center seat. That was followed by Kimbrough and then Borisenko.
They were carried one-by-one over to couches for initial health checks. The crew made post-landing phone calls via a satellite phone, likely to their families.
Within a few minutes, however, the crew, in their couches, were carried into an orange inflatable medical tent for more health checks and to be helped out of their Sokol suits.
After the on-site health checks were complete, the crew was helicoptered about two hours northeast to Karaganda, Kazakhstan, where they will be given a welcome ceremony before parting ways to their respective home countries.
The trio spent a total of 173 days, 3 hours and 15 minutes in space, flying around Earth inside the ISS for a total of 73.2 million miles (118 million kilometers).
This was Ryzhikov’s first spaceflight and Borisenko and Kimbrough’s second.
Ten days from now, another Soyuz will launch. Soyuz MS-04 will send Russian cosmonaut Fyodor Yurchikhin and NASA astronaut Jack Fischer to the space station to join Expedition 51.
Video courtesy of NASA
Derek Richardson has a degree in mass media, with an emphasis in contemporary journalism, from Washburn University in Topeka, Kansas. While at Washburn, he was the managing editor of the student run newspaper, the Washburn Review. He also has a blog about the International Space Station, called Orbital Velocity.