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Soyuz rocket flies critical test mission with Progress-MS
A new and improved Progress cargo ship was launched to the International Space Station, ISS, on December 21, 2015, and successfully reached its destination two days later. The latest upgrade of the veteran Russian space freighter and tanker was designated Progress-MS. In the ISS flight manifest, the first mission of the Progress-MS vehicle was known as 62P, while in the production documentation it was listed as No. 431.
Stop-and-go preparations for the first launch
Progress-MS spacecraft during vacuum testing in Baikonur.
The first Progress-MS spacecraft arrived to Baikonur on August 10, 2015. By the end of October, final vacuum tests on the ship had been completed and the spacecraft was largely ready for flight. However, the rocket for the mission was still undergoing last-minute upgrades to address issues discovered in the wake of the Progress M-27M failure.
As a result, the Progress-MS had to be to put in storage mode in Baikonur from the end of October until the second half of November.
In October, the launch of the first Progress-MS was postponed from November 21, 2015, (at 23:29:36 Moscow Time), to December 21, 2015.
The move had a domino effect of delays on several following ISS missions:
In addition, the launch of the ISS crew scheduled for March 19, 2016, was switched from the Soyuz-MS spacecraft to a regular Soyuz TMA-20, which previously was not expected to fly until May 2016.
In turn, Soyuz-MS was rescheduled to fly on June 21, 2016. Finally, the return of the Soyuz TMA-19M spacecraft was re-scheduled from May 5, 2016, to June 5, 2016. The rest of the publicly announced schedule included:
Launch campaign resumes
The Soyuz-2-1a launch vehicle for the mission was finally unloaded in Baikonur on November 26, 2015, at Site 31, clearing the way for the resumption of the launch campaign.
On December 8, the technical management responsible for the mission had a meeting in Baikonur, giving the green light to fueling of the spacecraft for launch. After the loading of propellants and pressurized gases, the ship returned to its processing building at Site 254 on December 11.
The assembly of the launch vehicle with the spacecraft was completed on December 18 and on the same day, the State Commission overseeing the launch gave the go ahead for the rollout to Pad 6 at Site 31 in Baikonur, starting at 04:30 Moscow Time (6:30 a.m. local time) next morning.
Cargo onboard Progress-MS:
During the launch on December 21, 2015, almost as important, if not more important than the introduction of the new Progress series, was a re-try of the Soyuz-2 rocket.
The rocket's previous launch with a cargo ship on April 28, ended up with what is believed to have been a violent disintegration of the third stage in orbit, which completely disabled the Progress M-27M cargo ship moments after its separation. Had the rocket carried the Soyuz spacecraft, the mission would most certainly have resulted in the loss of the crew!
The accident might be considered a blessing because according to the original plans, Progress launches on the Soyuz-2-1a were meant to certify the 2-1a variant for carrying manned Soyuz-MS spacecraft. At the time, the first manned mission of the Soyuz-2-1a rocket with a Soyuz-MS1 spacecraft was scheduled for March 2016.
Naturally, after the Progress M-27M accident, these plans had to be put on hold and the upcoming human missions had to be switched back to an older Soyuz-FG rocket. This was not an easy decision for Roskosmos, because the clock was ticking for the retirement of the previous-generation Soyuz-FG and Soyuz-U rockets.
For years, RKTs Progress in the city of Samara, the developer of Soyuz rockets, had urged Roskosmos to retire the FG and U series as soon as possible. The company struggled to maintain multiple variants in production and it had to procure flight control system for older variants in Ukraine. The problem with the flight control system escalated in the spring of 2014, after Russia had annexed Crimea and Ukraine responded with an embargo on most of its high-tech and defense exports to Russia. Without Ukrainian "brains," the FG and U variants could not fly.
Facing the possible loss of the FG and U variants, Roskosmos began in earnest the long-delayed certification of the Soyuz-2-1a for ISS missions on October 29, 2014, with the successful launch of the Progress M-25M spacecraft. However the second launch attempt on April 28, 2015, which would clear the rocket for carrying crews, ended with the loss of Progress M-27M.
In the aftermath of the accident, engineers suspected potentially fatal flaws in the design of the rocket's third stage, which was drastically different from the booster used on Soyuz-U and Soyuz-FG. Suddenly, Roskosmos found itself between a rock and a hard place, because RKTs Progress was running out of crucial components for U/FG variants, while Soyuz-2-1a now looked too dangerous for manned missions!
It reportedly took pressure on the Ukrainian government from the US State Department for Kiev to resume its supplies of components for Soyuz-U and FG variants.
Searching for a culprit
The original goal of the third stage re-design in the Soyuz-2 series was to accommodate the new RD-0124 engine, which featured the so-called staged combustion and required more liquid oxygen oxidizer than the amount consumed by the old RD-0110 engine. To increase oxidizer capacity, the oxygen tank of the third stage was stretched, while the fuel tank at the top of the stage was squashed. As a result, the oxygen tank now experienced more loads during the climb to orbit, while the front kerosene tank, which used to be suspended inside the stage and carried no structural loads now had to carry some.
Although only the 2-1b version of Soyuz was equipped with RD-0124, both 2-1a and 2-1b featured a redesigned third stage in order to maintain a common production line.
Before the Soyuz-2-1a lifted off on its fateful mission with Progress M-27M, the Soyuz-2 series logged 43 flights, including 21 flights of the 2-1a variant. None of the previous launches had apparently revealed any structural issues with the third stage. However, immediately after the accident, engineers suspected that the particular mass and shape of the Progress ship could create a unique situation for the so-called "coupled loads" between the two vehicles.
This particular configuration could match the so-called natural resonant frequency of the structure pushing it to a brink of disintegration. Accompanied by a powerful jolt at the engine shutdown at the end of the nine-minute powered ride to orbit, the combined loads could lead to a rupture of the stage, the same way the voice of an opera singer can shatter a champagne glass.
Although rocket stages routinely undergo ground tests to ensure their ability to withstand vibrations, the "coupled loads" with the Progress cargo ship could have been unique and undetected. Given the transient nature of vibration loads, the first Progress ship that successfully rode the Soyuz-2-1a rocket in October 2014, could have been simply lucky to avoid destruction.
In the wake of the Progress M-27M accident, Russian engineers had to re-test the stage, analyze the results and develop corrective measures to avoid the same situation in the future. In the end, specialists apparently came to the conclusion that the problem could be resolved by making the engine shutdown sequence more gentle. The third stage would also be equipped with additional sensors to verify its performance in flight. However reprogramming the engine cutoff and installing monitoring hardware still required more time than originally expected.
Struggling to complete the upgrades, while simultaneously supporting the ISS, Roskosmos had to postpone another attempt to launch Progress on Soyuz-2-1a from November 21 to December 21. The success of that launch should give some confidence to engineers in their upgrades, although more flights will likely be needed to fully re-habilitate the Soyuz-2 series.
To be on the safe side, Roskosmos might now stick with old versions of Soyuz rockets for all manned missions until as late as 2019!
Progress-MS embarks on its first mission
A Soyuz-2-1a rocket carrying the 7,284-kilogram Progress-MS cargo ship lifted off from Pad 6 at Site 31 in Baikonur on December 21, 2015, at 11:44:39.465 Moscow Time (3:44 a.m. EST). Inside, Progress carried around 2,436 kilograms of supplies for the 46th long-duration expedition on the ISS, including 718 kilograms of propellant in its refueling tanks, 420 kilograms of water and 46 kilograms of pressurized air and oxygen.
Following a vertical liftoff, the launch vehicle headed eastward from Baikonur to match an orbital inclination of 51.66 degrees. NASA and the Russian space agency confirmed that the spacecraft had separated from the third stage of the launch vehicle as scheduled and all its antennas and solar arrays had deployed as planned.
According to pre-launch calculations, the separation between the spacecraft and the third stage was scheduled at 11:53:26.93 Moscow Time (3:53 a.m. EST).
A post-launch report from the Russian mission control in Korolev confirmed that the vehicle's initial parking orbit was within specifications:
At the time when the Progress-MS had reached its initial orbit, the ISS was in a 399.18 by 416.14-kilometer orbit, 334.3 degrees away from the cargo ship in the so-called phasing angle.
Rendezvous and docking
Progress-MS is following a two-day rendezvous profile to test its new electronics and communications systems. In a few hours after the launch, NASA confirmed that the ship successfully conducted two planned engine firings during its third orbit on the first day of the mission. One additional maneuver was scheduled during the 18th orbit, on the second day of the flight.
As Progress-MS proceeded to make its first revolution around the Earth, specialists at RKK Energia for the first time communicated with the transport ship via a relay satellite, the company announced next day. According to RKK Energia, no previous Progress or Soyuz spacecraft ever had such a capability.
Around 10 minutes after the separation from the launch vehicle, Progress-MS conducted a turn to orient itself toward the Luch-5B satellite, then located at 16 degrees West longitude.
Progress-MS was scheduled to begin, the autonomous rendezvous with the station on December 23, 2015, at 11:10:11 Moscow Time (3:10 a.m. EST).
The docking at the Pirs Docking Compartment, SO1, a part of the Russian segment of the ISS, was scheduled for December 23, 2015, at 13:31:29 Moscow Time (5:31 a.m. EST), during the ship's 34th orbit. The actual docking took place around four minutes ahead of schedule at 13:27 Moscow Time. The only glitch during the final approach was a communication problem between the TORU remote-control system on the station and the rendezvous system on the Progress, leaving the crew without a backup option in case of problems with an automated approach of the spacecraft. Fortunately, TORU was not needed, as all systems on Progress-MS performed as planned, NASA said.
The first Progress-MS is expected to remain docked at the ISS until July 2016.
Factual docking timeline between Progress-MS and ISS on Dec. 23, 2015:
On July 1, 2016, at 08:35 Moscow Time (1:35 a.m. EDT), the Progress-MS cargo ship was scheduled to undock from the Pirs Docking Compartment (SO1) on the Russian segment of the ISS to test cosmonaut-operated docking system, TORU. The spacecraft was expected to reach a distance of around 200 meters from the outpost, before cosmonauts Aleksei Ovchinin and Oleg Skripochka would use a pair of joy sticks on their TORU console inside the Zvezda Service Module (SM) to manually guide the ship back to the Docking Compartment and re-dock it at 09:10 Moscow Time (2:10 a.m. EDT). The crew can use one hand controller of the TORU to affect the lateral movement of the spacecraft and another to change its attitude (orientation) in space based on live TV images sent to the monitor of the TORU console from the incoming vehicle. The system is designed as a backup for an automated rendezvous and docking system. The latest TORU test aimed to certify its compatibility with newly upgraded rendezvous equipment on the Progress-MS and Soyuz-MS series.
The exercise commenced with undocking at 08:36 Moscow Time (1:36 a.m. EDT) and proceeded few minutes ahead of schedule, but during the final few meters during the approach, the crew reported problems with TORU in its communications with the Russian mission control in Korolev and officials on the ground were heard advising the cosmonauts to switch from manual to automated control.
Then, during berthing of the spacecraft, a considerable pitch movement of the spacecraft was clearly visible on live TV broadcast, apparently related to an accidental firing of attitude-control thrusters, DPOs, aboard the cargo ship.
Unusually intense thruster firings had been observed during the berthing of the ship.
Yet, despite an obvious glitch during docking, Roskosmos issued a statement, claiming that the test was successful and concluded with manual docking at 09:04 Moscow Time (2:04 a.m. EDT) on July 1, 2016. No further details had been provided.
Following the exercise, the Progress-MS was undocked from the ISS as scheduled on July 3, 2016, at 06:48 Moscow Time (11:48 p.m. on July 2). The spacecraft initiated a braking maneuver at 10:03 Moscow Time (3:03 a.m. EDT) on July 3, resulting in a planned destructive reentry over the Pacific Ocean, west of New Zealand. Any surviving debris were projected to hit the ocean surface around 10:50 Moscow Time (3:50 a.m. EDT).
Read much more about the history of the Russian space program in a richly illustrated, large-format glossy edition:
Progress-MS unloaded in Baikonur on Aug. 10, 2015. Click to enlarge. Credit: Roskosmos
A Soyuz-2-1a rocket for the Progress-MS mission is being unloaded at Baikonur's Site 31 on Nov. 26, 2015. Click to enlarge. Credit: Roskosmos
The final inspection of the Progress-MS1 spacecraft on Dec. 16, 2015. Click to enlarge. Credit: RKK Energia
Progress-MS is being integrated with a launch vehicle adapter on Dec. 14, 2015. Click to enlarge. Credit: RKK Energia
Progress-MS is being integrated with its payload fairing on Dec. 16, 2015. Click to enlarge. Credit: RKK Energia
A third stage of the Soyuz-2-1a rocket during final assembly of the launch vehicle for the Progress-MS mission on Dec. 18, 2015. Click to enlarge. Credit: Roskosmos
Click to enlarge. Credit: Roskosmos
Soyuz-2-1a rocket with Progress-MS-1 spacecraft shortly after arrival at Site 31 on December 19, 2015. Click to enlarge. Credit: Roskosmos
Gantry is retracted from Soyuz-2-1a rocket with Progress-MS spacecraft shortly before liftoff on dec. 21, 2015. Click to enlarge. Credit: Roskosmos
Progress-MS lifts off on Dec. 21, 2015. Click to enlarge. Credit: Roskosmos
View of the ISS from the approaching Progress-MS spacecraft on Dec. 23, 2015. Credit: NASA
Approaching Progress-MS as seen from ISS on Dec. 23, 2015. Credit: NASA