The Russian Soyuz MS-11 spacecraft undocked from the International Space Station (ISS) on Monday and returned NASA astronaut Anne McClain, Soyuz Commander Oleg Kononenko of Roscosmos, and Flight Engineer David Saint-Jacques of the Canadian Space Agency to Earth. The End Of Mission events began on Sunday, with a Space station change of command ceremony, during which Konenenko handed over command to Roscosmos cosmonaut Alexey Ovchinin. Undocking took place at 7:25 pm Eastern on Monday and landing followed at 10:47 pm Eastern.
The crew completed a 204-day mission spanning 3,264 orbits of the Earth and a journey of 86.4 million miles.
McClain first trip into space has been a busy mission, including two spacewalks that completed a battery swap-out and worked on the Station’s power systems.
Among her numerous tasks on the Station, McClain also took part in welcoming the first Commercial Crew vehicle to the ISS, as Dragon 2 completed its opening DM-1 flight.
She also made friends with one of Dragon’s passengers, leading to numerous viral tweets and an unaware producer of “Little Earth” toys running out of stock.
David Saint-Jacques of the CSA also completed his first spaceflight and was involved with one of McClain’s EVAs, his first.
Following McClain’s tour of the ISS, Saint-Jacques was also heavily involved with the Visiting Vehicles that arrived and departed from the ISS, which involved obvious synergy via the use of the Canadian robotic assets. He was last involved with the departure of the CRS-17 Dragon, which was released by the Canadian SSRMS (Space Station Remote Manipulator System).
Saint-Jacques’ mission was the longest single spaceflight by a Canadian astronaut.
They were transported home under the command of Kononenko, logging 737 days in space on his four flights, putting him in sixth place on the all-time list of space travelers for cumulative time.
Following the handover ceremony, McClain closed the hatch to their Soyuz MS-11 spacecraft Monday afternoon and undocked from the station.
Following undocking, Soyuz enjoyed a few hours of free flight as it departed from the Station’s neighborhood via two separation burns while the onboard crew prepared for the final aspect of their mission.
The deorbit burn occurred at 9:55 p.m Eastern, reducing the Soyuz’s velocity just enough for it to begin the plunge back to Earth via a 4 min, 40 second retrograde firing.
The Soyuz then entered the critical part of its mission as the spacecraft had no other option but to re-enter.
The first milestone was module separation as the three major elements of the Soyuz spacecraft – the OM, DM and Instrumentation/Propulsion Module (IPM) – were pushed apart via the use of pyrotechnics.
All three modules nominally separate simultaneously – shortly after the deorbit burn is completed – at around 140 km altitude.
Two “off nominal” re-entries occurred in 2007 and 2008 and were the cause of separation failures on the modules, thus initiating a very stressful return for their three-person crews.
Known as “ballistic entry” – the crew have to endure much higher G-forces and land at an alternative site.
An investigation (L2 Russian Section) noted issues with the long-term exposure to electromagnetic emissions on-orbit, and the potential to cause issues with the pyro bolts, came after an extensive investigation that included the removal and return of one pyro bolt from Soyuz TMA-12.
Mitigation against this issue has resulted in no further issues with the module separation milestone in any of the following missions.
Once through the plasma of entry interface, the capsule was prepared for the deployment of its drogue chute. This readies the spacecraft for the deployment of its main parachute.
This is one of the hardest parts of the return for the crew, which has been described as being inside a washing machine by some returning astronauts.
The Soyuz craft then completed the return to terra firma, landing on the steppes of Kazakhstan, marked at 10:48 p.m Eastern.
The exact timing of touchdown, under a “soft” thruster engine firing, is always dependent on a number of factors – such as the impact of winds on the Soyuz chutes – and can vary by several minutes.
With the Soyuz safely back on Earth, ground and air crews converged on the Soyuz to extract the crew from the SA.
The crew will underwent immediate and preliminary health checks once outside their Soyuz spacecraft. All three were then transferred to a medical tent and then prepared for transit away from the landing site.
After landing, the crew returned by helicopter to the recovery staging area in Karaganda, Kazakhstan, where McClain and Saint-Jacques will board a NASA plane for their return to Houston, and Kononenko will return to his home in Star City, Russia.