Mission of Soyuz TMA-20M
The Soyuz TMA-20M spacecraft lifted off on March 19, 2016, carrying three members of the 47/48th long-duration expeditions onboard the International Space Station, ISS. Being the 46th Soyuz vehicle heading to the outpost, the mission had a designation 46S in the ISS flight manifest. The spacecraft and its crew were scheduled to remain in orbit for half a year and return to Earth on Sept. 7, 2016. It will be the final vehicle in the Soyuz TMA-M series to be replaced by Soyuz-MS.
The crew of Soyuz TMA-20M spacecraft (left to right): NASA astronaut Jeffrey Williams and Russian cosmonauts Aleksey Ovchinin and Oleg Skripochka
Soyuz TMA-20M mission at a glance:
The launch vehicle with the spacecraft was rolled out to the launch pad No. 5 at Site 1 in the early hours of March 16, 2016, however due to strong wings reaching 24 meters per second at the site, the installation of the rocket into vertical position had to be postponed.
According to Roskosmos, the new time for erecting the rocket on the pad was to be set during a meeting at 14:00 Moscow Time (7:00 a.m. EDT), taking into account the actual weather situation. The postponing the launch from March 19 is not considered at this point, the agency said. Following the meeting, Roskosmos announced that the weather at the launch site had improved and the installation of the rocket would resume at 18:00 Moscow Time (11 a.m. EDT). The vehicle finally took vertical position on the pad in night darkness unusual for this operation, which is traditionally conducted in the morning.
The launch of the Soyuz TMA-20M spacecraft took place as scheduled on March 19, 2016. A Soyuz-FG rocket lifted off from Pad 5 at Site 1 in Baikonur Cosmodrome at 00:26:38.355 Moscow Time (5:26 p.m. EDT or 09:26 GMT on March 18). Commander Aleksey Ovchinin occupied central seat inside the descent module of the Soyuz spacecraft, with Oleg Skripochka to his left and Jeffrey Williams to his right.
The launch vehicle propelled by the simultaneous thrust of four engines of the first stage and one engine of the second stage headed east to align its ascent trajectory with the orbital plane inclined 51.67 degrees toward the Equator. Slightly less than two minutes into the flight, the ship's emergency escape system separated, immediately followed by four boosters of the first stage. The second (core) stage of the booster continue firing for less than five minutes into the flight. Moments before its separation, the four-chamber engine of the third stage ignited, firing through a lattice structure connecting two boosters. Following the separation of the core booster, the tail section of the third stage split into three segments and fell away.
The spacecraft separated from the third stage of the launch vehicle around nine minutes into the flight, at 00:35:27 Moscow Time (5:35 p.m. on March 18) in an orbit with following parameters:
Without any additional maneuvers the spacecraft would remain in orbit for around 20 revolutions around the Earth during the next 30 hours, before reentering into the Earth's atmosphere.
Upon reaching orbit, the Soyuz TMA-20M ended up 31.6 degrees away from the ISS. At the time, the station was orbiting the Earth in a 403.51 by 421.29-kilometer orbit with an inclination 51.65 degrees.
The mutual position of the two spacecraft was allowing docking on the day of the launch (March 19) within six hours after liftoff. The Soyuz conducted four orbital maneuvers, which were to bring the spacecraft into the vicinity of the station by the beginning of the fifth orbit of the Soyuz TMA-20M mission:
Following its orbit corrections, Soyuz TMA-20M began an autonomous rendezvous with the ISS around 04:03:38 Moscow Time on March 19 (9:03 p.m. EDT).
The final maneuvers, including flyaround, a short station-keeping period and berthing, were scheduled to be initiated at 05:47:09 Moscow Time on March 19 (10:47 p.m. EDT on March 18) in fully automated mode.
The docking of Soyuz TMA-20M with the ISS was scheduled on the day of the launch at 06:11:47 Moscow Time (11:11 p.m. EDT on March 18). The actual first contact between the two spacecraft took place at 11:09:55 p.m. EDT on March 18.
As originally planned, the landing of the Soyuz TMA-20M spacecraft is scheduled on Sept. 7, 2016, after 172 days in space. The return to Earth began on September 6, with the transfer of the crew from the International Space Station, ISS, to the transport ship and the closure of the hatches at 21:42 Moscow Time (2:42 p.m. EDT). Russian cosmonauts Aleksey Ovchinin, Oleg Skripochka and NASA astronaut Jeffrey Williams, comprising Expedition 48 aboard the ISS, entered the descent module of the Soyuz and donned their Sokol launch and entry suits. Ovchinin took the center seat, with Skripochka to his left and Williams in the right seat.
NASA promised good weather at the landing site with mostly clear sky, winds around eight knots and temperature of 66 F degrees.
Following leak checks, the separation of the spacecraft from the zenith-pointing MIM2 Poisk module on the Russian segment took place as scheduled on September 7, at 00:51:30 Moscow Time (5:51 p.m. EDT on September 6), just half a minute after the undocking command, as the spacecraft flew over Eastern Mongolia.
Three minutes after being gently pushed away from the station with the help of springs of the docking mechanism, Soyuz TMA-20M fired its small attitude control thrusters for eight seconds to conduct separation maneuver to increase its distance from the ISS. Another 30-second maneuver was conducted a minute and 20 seconds later.
At 03:21:25 Moscow Time on September 7 (8:21 p.m. EDT on September 6), over the Southern Atlantic, while still more than 400 kilometers above the Earth, the Soyuz TMA-20M fired its main engine for four minutes and 41 seconds to conduct the braking maneuver. It slowed down the spacecraft by 128 meters per second and initiated the deorbiting process. Around 22 minutes later, now 140 kilometers above the Red Sea, the descent module carrying the crew separated from the habitation compartment and the instrument module. Less than three minutes later, the descent module reentered the discernable atmosphere at an altitude of around 100 kilometers. Almost immediately, the capsule's flight control system began using lifting effect of the rarified air to adjust a steep ballistic trajectory into a more gentle aerodynamic descent over the Caspian Sea. The crew was expected to experience the maximum deceleration force not exceeding 3.84 G, less than five minutes later.
The release of the three-tier parachute of the descent module was initiated at an altitude of 10.8 kilometers above the Earth's surface, around 04:00 Moscow Time on September 7 (9:00 p.m. EDT on September 6).
The descent module of the Soyuz TMA-20M spacecraft touched down as scheduled at 04:13:53 Moscow Time on September 7 (9:13 p.m. EDT on September 6), 148 kilometers southeast of Dzhezkazgan in Kazakhstan. The landing was timed to take place just 24 minutes after local sunrise to give search and rescue services most of the daylight period for the crew recovery operations before the local sunset at 16:47 Moscow Time (9:47 a.m. EDT).
A total of 12 Mi-8 helicopters were expected to participate in the search and rescue effort, with eight of them scheduled to take off from Dzhezkazgan around the time of the deorbiting maneuver for a 40-minute flight to the primary landing site. Another pair of helicopters was deployed at the Krainy airport in Baikonur to support an unlikely ballistic landing, which would take place short of the primary site. Two more helicopters were deployed near a half-way point between the primary and backup landing sites, ready to support both scenarios.
Aboard the ISS, the departure of Soyuz TMA-20M marked the beginning of Expedition 49 under the command of Anatoly Ivanishin of Roskosmos. He is accompanied by NASA astronaut Kate Rubins and Takuya Onishi representing the Japan Aerospace Exploration Agency, JAXA. The three-person crew will operate the station for more than two weeks until the arrival of three additional crew members on the Soyuz MS-02 spacecraft. Shane Kimbrough of NASA and cosmonauts Sergey Ryzhikov and Andrey Borisenko of Roskosmos are scheduled to launch from Baikonur Cosmodrome on Sept. 23, 2016. Ivanishin, Rubins and Onishi will then depart the station onboard the Soyuz MS-01 spacecraft on Oct. 30, 2016.
Planned landing timeline for Soyuz TMA-20M on Sept. 7, 2016, Moscow Time:
Descent module of Soyuz TMA-20M touches down on Sept. 7, 2016.
Soyuz TMA-20M primary and backup crew:
Soyuz TMA-20M mission logo. Credit: Roskosmos
Soyuz TMA-20M is being prepared for integration with its launch vehicle adapter on March 9, 2016. Click to enlarge. Credit: RKK Energia
Integration of the payload section of the Soyuz TMA-20M spacecraft with the Soyuz FG launch vehicle. Click to enlarge. Credit: Roskosmos
Descent module of the Soyuz TMA-20M spacecraft under a parachute during landing on Sept. 7, 2016. Click to enlarge. Credit: Roskosmos