After bidding their crewmates farewell, a Russian cosmonaut and two NASA astronauts boarded their Soyuz ferry craft and undocked from the International Space Station Tuesday, which set up a fiery return to Earth with a landing on the snowy steppe of Kazakhstan to close out a 168-day mission.
With cosmonaut Alexander Misurkin at the controls in the Soyuz MS-06 spacecraft’s center seat, flanked on the left by flight engineer Mark Vande Hei and on the right by Joe Acaba, the Russian spacecraft separated from the upper port of the station’s Poisk module at 6:08 p.m. EST (GMT-5) to begin the three-and-a-half-hour trip home.
With cold, wintry weather expected in Kazakhstan, touchdown about 90 miles from the town of Dzhezkazgan was targeted for 9:31 p.m. Video from the scene showed they landed around that time.
During a change-of-command ceremony Monday, Misurkin, commander of Expedition 54, turned over responsibility for the station to Anton Shkaplerov, who will command Expedition 55, and his two Soyuz MS-07 crewmates, Scott Tingle and Japanese astronaut Norishige Kanai.
Misurkin, speaking in English, thanked flight controllers around the world for allowing his crew “to use this station. We didn’t (break) almost anything, and hope we did some good things and helpful things for science. Looking forward now to going home, back to the Earth, to work with you guys on the ground.”
The returning Soyuz MS-06 crew (left to right): Joe Acaba, vehicle commander Alexander Misurkin and flight engineer Mark Vande Hei.
NASA
Said Shkaplerov: “You did very good job here on board International Space Station, and now you are ready to return to our planet.”
“Alexander, I am proud to be part of the great team you have been leading here,” he said. “Station is in excellent condition, and we’ll do all the best keeping this unique scientific laboratory fully functional and safe. With honor, I am taking command.”
Misurkin and his two NASA crewmates shared a final round of hugs and handshakes with Shkaplerov, Tingle and Kanai Tuesday afternoon and then floated into their Soyuz spacecraft, closing the hatch at 2:58 p.m.
After departing the station, the flight plan called for Misurkin to move the ship to a point about 12 miles from the station. Once in place, Misurkin and Vande Hei expected to monitor an automated four-minute 39-second rocket firing starting at 8:38 p.m., slowing the ship by about 296 mph and dropping the far side of the orbit deep into the atmosphere.
After a half-hour free fall, the three modules making up the Soyuz MS-06 spacecraft will separate and the crew, strapped into the central descent module — the only one equipped with a protective heat shield — was expected to slam into the discernible atmosphere at an altitude of 62 miles at 9:08 p.m.
Two minutes later, the descent module, still moving at nearly 5 miles per second, will begin about 15 minutes of extreme heating as it rapidly decelerates, subjecting the crew to about three times the normal force of gravity.
The spacecraft’s main parachute will unfurl at an altitude of about 6.5 miles and the descent module will settle to a bumpy rocket-assisted touchdown about 14 minutes later.
Russian recovery crews and medical personnel, along with a contingent representing NASA, will be stationed nearby and should be on the scene within minutes to help the returning station fliers out of the cramped capsule as they begin readjusting to the unfamiliar tug of gravity. And an equally unfamiliar blast of wintry weather.
An on-time touchdown would close out a 168-day five-hour mission since launch from the Baikonur Cosmodrome last Sept. 12, a flight spanning 2,688 orbits and 71.1 million miles.
With landing, Misurkin’s total time in space over two station flights will stand at 334 days while Acaba, veteran of a space shuttle flight and a previous station visit, will have logged 306 days aloft. Vande Hei is wrapping up his first space mission.
During their stay in orbit, the crew helped unload four visiting cargo ships, welcomed Shkaplerov’s crew aboard and monitored the departure of five visiting vehicles. All three also participated in multiple spacewalks, with Misurkin and Acaba each taking part in single excursions while Vande Hei took part in four.
After medical checks, all three crew members will be flown by helicopter to Karaganda. From there, Misurkin will board a Roscosmos jet and fly home to Star City near Moscow while Vande Hei and Acaba take a NASA plan back to the Johnson Space Center in Houston.
Meanwhile in orbit, Shkaplerov, Tingle and Kanai will have the station to themselves until March 23 when three fresh crew members arrive: Soyuz MS-08 commander Oleg Artemyev and NASA astronauts Ricky Arnold and Drew Feustel.
The space station’s crew normally is evenly split between the Russians and the U.S. segment, with three cosmonauts responsible for the lab’s Russian modules and three astronauts, representing NASA, ESA, Japan and Canada, operating systems and carrying out research in modules supplied by NASA, ESA and Japan.
A shot of Earth taken through the station’s multi-window Cupola compartment. Joe Acaba tweeted: “The future of our home is in all of our hands. May we all care for #Earth and practice good stewardship.”
NASA
NASA is responsible for arranging transportation for the station’s non-Russian crew members, known collectively as U.S. Operating Segment — USOS — astronauts.
The Russians decided in late 2016 to downsize their crews in the near term to save money, a decision that freed up seats aboard upcoming Soyuz spacecraft.
At roughly the same time, Boeing and the Russian aerospace company Energia reached a settlement in a $320 million dispute involving the Sea Launch commercial rocket company. As part of the settlement, Boeing obtained two Soyuz seats, one in 2017 and another in 2018, with options for three more.
NASA eventually agreed to buy all five seats from Boeing for an average cost of $74.7 million each, according to Space.com, modifying an existing contract with the Russians.
The two near-term seats allowed NASA to expand the USOS segment of the station crew from three to four, sharply increasing the crew time available for research. The other seats will serve as insurance in case commercial ferry ships being built by Boeing and SpaceX are delayed, requiring additional Soyuz flights for USOS crew members.
As of this writing, SpaceX or Boeing plan to launch unpiloted test flights of their new spacecraft around the end of August. If one or both of those flights gets off on time, the first piloted test flight, by either SpaceX or Boeing, could come in late December.
In the meantime, the Russians plan to resume their normal staffing levels after Feustel and Arnold return to Earth on Aug. 28.
But once the Boeing and SpaceX crew ships are certified for regularly scheduled flights to the station, NASA will be able to carry three USOS crewmates at a time, along with at least one cosmonaut, while Russian Soyuz spacecraft will routinely carry two cosmonauts and one NASA astronaut.
That will result in seven-member station crews in 2019 with four USOS astronauts aboard for the duration of the program, allowing NASA to maintain a high science output.
“Right now, having four USOS crew members on board, it gives you a lot more opportunities, not only to maintain the space station but then do the science we’re up there for,” Acaba said. “I think the number I heard is somewhere around 800 more hours of utilization. That’s a big chunk of science we’re going to be able to do by adding an extra crew member. So it’s pretty cool.”
