Less than 24 hours since departing the Baikonur Cosmodrome in Kazakhstan, the Soyuz TMA-19M crew of Russian cosmonaut Yuri Malenchenko, U.S. astronaut Tim Kopra, and Britain’s Tim Peake are settling aboard the International Space Station (ISS) as the second half of Expedition 46, under the command of NASA’s Scott Kelly. Their arrival heralds the final phase of the joint U.S./Russian One-Year Mission, which will see Kelly and Russia’s Mikhail Kornienko return to Earth in early March 2016, alongside veteran cosmonaut Sergei Volkov. After this, Kopra will rotate into the command of Expedition 47 through early June. Slated to spend almost six months aboard the ISS, Malenchenko, Kopra, and Peake will oversee as many as six Visiting Vehicles (VVs) and perform up to four EVAs.
As outlined in yesterday’s AmericaSpace launch article, Soyuz TMA-19M roared aloft from Site 1/5 (the historic “Gagarin’s Start”) at the Baikonur Cosmodrome in Kazakhstan at 5:03:10 p.m. local time (6:03 a.m. EST) Tuesday and following orbital injection adopted a now-standard six-hour “fast rendezvous” profile to reach the ISS. That said, the docking was not without its dramas, for the automated “Kurs” (“Course”) rendezvous apparatus failed during the final approach, requiring Commander Malenchenko to assume control and perform a smooth manual docking at the Earth-facing (or “nadir”) port of the station’s Rassvet module at 12:33 p.m. EST. A little over two hours later, at 2:58 p.m., the hatches were opened and the new arrivals were welcomed aboard by the incumbent Expedition 46 crew. Later in the day, Tim Kopra became the first Soyuz TMA-19M crewman to send a post-launch tweet to his Earthly following. “Awesome ride!” he told his 34,800 followers, sharing a NASA image of the liftoff. “Thanks to all the great training teams that helped make it happen.”
Malenchenko, Kopra, and Peake arrived at a station which already played host to the Soyuz TMA-18M spacecraft, belonging to Kelly, Kornienko, and Volkov, as well as three incumbent VVs: Russia’s Progress M-28M and M-29M cargo ships, launched in July and October 2015, which respectively occupy the Earth-facing (or “nadir”) port of the Pirs module and the aft longitudinal port of the Zvezda service module, and Orbital ATK’s OA-4 Cygnus, which arrived last week and was berthed at the nadir interface of the Unity node. Their next visitor, scheduled to fly from Baikonur on 21 December, is “Progress-MS,” the first member of an upgraded variant of the unpiloted Russian cargo ship, which can trace its ancestry back to the late 1970s, having also supported the Salyut 6 and 7 and Mir space stations.
In order to make room for the incoming cargo ship, the old Progress M-28M will be undocked from Pirs nadir on 19 December and destructively deorbited over the Pacific Ocean. This will allow Progress-MS—which benefits from improved redundancy in its docking hardware, enhanced Micrometeoroid Orbital Debris (MMOD) protection, better telemetry, control, and autonomous navigational capabilities, the digital “Kurs-NA” (“Course”) rendezvous apparatus, and an external compartment, capable of deploying small satellites—to achieve a link-up with the ISS on 23 December. Whereas most Russian vehicles typically follow the six-hour “fast rendezvous” protocol, this maiden voyage of Progress-MS will adopt the protracted approach profile. “Docking is automated,” NASA’s Rob Navias told AmericaSpace. “Two-day rendezvous enables Russian flight controllers to test software and upgraded telemetry systems.” In addition to water, food, clothes, and propellant, Progress-MS is expected to deliver the second shipment of Christmas gifts for the Expedition 46, following OA-4’s early visit from Santa on 9 December.
Spending Christmas and the New Year together, the six-man crew will kick off an ambitious 2016, which has already seen some manifest changes in recent days. The Commercial Resupply Services (CRS)-8 Dragon cargo mission, carrying the long-awaited Bigelow Expandable Activity Module (BEAM)—previously scheduled to fly in early January—has reportedly moved to a No Earlier Than (NET) 8 February target date, “to allow SpaceX to complete its evaluation of preparations for launch,” Mr. Navias told AmericaSpace. This has allowed the next spacewalk from the U.S. Orbital Segment (USOS) to be correspondingly moved forward. As noted in a recent AmericaSpace article, U.S. EVA-34 was informally scheduled for late January and, according to Mr. Navias, could have taken place anytime in the January-February timeframe, “but we will take the opportunity now to complete it in Jan.”
“The EVA will be in a window between Jan 15-19, when the beta angle is correct for the prime task of swapping out the 1B Sequential Shunt Unit (SSU),” he told AmericaSpace, noting that the spacewalk will run for a standard 6.5 hours. The need to replace the 1B unit—one of a total of eight SSUs, each weighing 186 pounds (84 kg), which help to regulate the power generated by the expansive Solar Array Wings (SAWs) at an established “set-point” of 160 volts, by shunting and unshunting 82 array “strings,” thus ensuring steady electrical output across the space station—has become necessary following last month’s failure of Power Channel 1B on the S-6 truss. Although the channel itself was quickly recovered, its loss was traced to a power short within the SSU, which tripped the Direct Current Switching Unit (DCSU). A similar situation arose in May 2014, when Power Channel 3A on the S-4 truss failed and its SSU was later replaced by Expedition 41 spacewalkers Reid Wiseman and Barry “Butch” Wilmore during U.S. EVA-28 the following October.
An SSU failure does not require a Critical Contingency EVA and it was stressed at the time that “Ground teams are discussing future repair plans and are currently able to manage the power balance for the foreseeable future.” Mr. Navias told AmericaSpace in November that “No specific forward plan has been identified, but ultimately we will need to fly a spare SSU to the station to replace the failed 1B SSU.” For U.S. EVA-34, the “replacement” SSU is currently inside the station and will be transported by the spacewalkers to the S-6 worksite, which lies at the furthest-outboard starboard side of the expansive Integrated Truss Structure (ITS). Mr. Navias stressed that the spare unit must undergo on-board testing ahead of the EVA, to ensure that it is in good shape, and it remains to be seen when a “replacement for the replacement” SSU will be launched. Meanwhile, the failed SSU is expected to return to Earth aboard the CRS-8 Dragon spacecraft in March 2016.
“SSU replacements are part of generic training for any potential EVA crewmember,” he explained. “They [the Expedition 46 crew] will study video and procedures and have tag-ups with EVA specialists on the ground before executing the spacewalk.” However, it was noted that “other tasks” for U.S. EVA-34 and the identities of which USOS crewmenwill perform the spacewalk “are still in work” at this time. Also undefined at present are plans for U.S. EVA-35 and 36, tentatively scheduled for April 2016, which are expected to come after the arrival of SpaceX’s CRS-9 Dragon. Since the principal payload for the latter is the second International Docking Adapter (IDA-2), it is expected that EVA-35 will be assigned to install and activate the new unit, although the specific tasks for EVA-36 remain To Be Determined (TBD).
Following the failure of IDA-1 to achieve orbit in June, aboard SpaceX’s ill-fated CRS-7 mission, IDA-2 will now fulfil the former IDA-1 role and be installed onto Pressurized Mating Adapter (PMA)-2 at the forward port of the space station’s Harmony node. Plans call for the IDA to be removed from Dragon’s unpressurized trunk and maneuvered a few inches from the PMA-2 interface, allowing the U.S. EVA-35 spacewalkers to complete required electrical, power, and data connections. In so doing, IDA-2 will provide the primary interface for Boeing’s Starliner and SpaceX’s Crew Dragon commercial vehicles, when they enter service in 2017. A replacement for IDA-2, known as “IDA-3,” is under construction from spares, and is expected to ride SpaceX’s CRS-14 into orbit, sometime in 2017. It will be attached onto PMA-3 at the space-facing (or “zenith”) port of Harmony. However, the extensive delays have already prompted NASA to indefinitely postpone its plans to relocate PMA-3—originally timetabled for October 2015—from its current berth on the Tranquility node to Harmony zenith. No new date for the PMA-3 relocation has been released.
One other EVA is planned for the first half of 2016, with cosmonauts Yuri Malenchenko and Sergei Volkov expected to spend 6.5 hours outside the Russian Orbital Segment (ROS) on 3 February, although exact details remain to be finalized, according to Mr. Navias.
Dovetailed into a busy EVA manifest are a series of unpiloted VVs, including Progress-MS and a second vehicle, Progress MS-2, which will arrive on 31 March and take the place of the Progress M-29M, which is scheduled to vacate the Zvezda aft longitudinal port a few days earlier. Two Orbital ATK Cygnuses are also scheduled to fly in March and May, the latter of which will launch atop the new Antares 230 booster. Meanwhile, SpaceX’s CRS-8 Dragon has moved from early January to no sooner than 8 February, thereby removing the possibility of having both of NASA’s Commercial Cargo partners on-station simultaneously. Orbital ATK’s OA-4 Cygnus will be unberthed from Unity nadir in late January and, following the arrival of SpaceX’s Dragon a couple of weeks later, the process of extracting and installing BEAM will get underway. The inflatable module will be removed from Dragon’s unpressurized trunk and installed, by means of the 57.7-foot-long (17.6-meter) Canadarm2 onto the aft-facing port of the Tranquility node.
“BEAM is a combined ground and crew operation,” Mr. Navias told AmericaSpace, “somewhere around 5 days or so after Dragon berthing.” NASA’s Dan Huot added that the movement of the inflatable module would be conducted remotely by controllers at the Mission Control Center (MCC) at the Johnson Space Center (JSC) in Houston, Texas, and at the Canadian Space Agency’s (CSA) Mission Control Centre, near Montreal. “NASA astronauts aboard the station will operate the Common Berthing Mechanism (CBM) at [Tranquility] aft to rigidly attach the new module,” Mr. Huot told AmericaSpace. “The operations are expected to take eight hours.” He pointed out that the actual “expansion” of BEAM will occur “within four months” of its installation. Beyond the attachment of BEAM, Mr. Navias pointed out that “no timetable” had been set for the initial crew ingress or activities inside the module, but stressed that “it will not be immediately.”
This will be close to the scheduled return to Earth of Kelly, Kornienko, and Volkov aboard Soyuz TMA-18M on 2 March. Wrapping up almost a full year—about 342 days—in orbit, Kelly and Kornienko will complete the fourth-longest single space mission ever attempted and the first flight of such extreme duration in the ISS era. Meanwhile, Volkov, who has joined them for the second half of their lengthy voyage, will land after six months in space. Prior to the departure of Soyuz TMA-18M from the Poisk module, Kelly will relinquish command of the station to Tim Kopra, who will lead Expedition 47 through his own return to Earth in early June. Two weeks later, on 19 March, Soyuz TMA-20M will launch from Baikonur and dock at Poisk, bringing the second half of the Expedition 47 crew: NASA astronaut Jeff Williams and Russian cosmonauts Alexei Ovchinin and Oleg Skripochka.
And therein lies the reason for the slightly extended increment of Malenchenko, Kopra, and Peake, who were originally scheduled to return to Earth on 5 May, but will now remain aboard the station through 5 June. The reason is associated with the debut of a new piloted Soyuz craft—known as “Soyuz-MS,” equipped with higher-efficiency solar arrays, better propulsion-system redundancy, the new Kurs-NA rendezvous apparatus, a lighter flight computer, and improved telemetry, control, and autonomous navigational capabilities—which was expected to make its maiden voyage in March with the Williams/Ovchinin/Skripochka crew. However, it was recognized that Soyuz MS-1 would not be ready in time for a March launch and it was swapped with Soyuz TMA-20M (the last member of the older-specification version of the spacecraft), which was originally earmarked to carry Russian cosmonaut Anatoli Ivanishin, NASA astronaut Kate Rubins, and Japan’s Takuya Onishi aloft in May. Ivanishin’s crew will now fly the Soyuz MS-1 and to ensure adequate time to prepare the new Soyuz, their launch date has been moved back to NET 21 June and the increment of Malenchenko, Kopra, and Peake correspondingly extended to limit the amount of time that the station would be reduced to three-crew capability.
With their mission thus extended from five to almost six months, Expedition 46/47 promises to make Malenchenko one of the world’s most seasoned spacefarers. The cosmonaut, who became only the second Russian after Sergei Krikalev to chalk up as many as six discrete missions, had already accrued more than 641 days—about 21 months of his life—in space before yesterday’s launch, thereby positioning himself as the seventh most experienced spacefarer in the world. He will progress up the experience table rapidly, entering sixth place by Christmas Day and should pass Krikalev’s 803-day total in early May 2016 to reach second place. Assuming an on-time landing of Soyuz TMA-19M on 5 June, Malenchenko looks set to establish a career total of 832 days, about 6.5 weeks shy of the 878 days held by current world space-endurance record-holder Gennadi Padalka.