Despite the scheduled return of US domestic crew launch capability this year, NASA is set to purchase more rides on the Russian Soyuz through 2020. The agency is adhering to a recommendation from its Aerospace Safety Advisory Panel (ASAP) after concerns were raised about the lack of a back-up option covering the potential delays that could be suffered during a challenging test flight phase for Dragon 2 and Starliner.
The United States has been using the Soyuz vehicle as a means of transporting its astronauts since the retirement of the Space Shuttle fleet in 2011. However, NASA’s reliance on the Soyuz vehicle as a back-up option has historical precedent, including its vital transportation role during the grounding of the Shuttle fleet following the loss of Columbia in 2003.
The long gap between the conclusion of STS-135 and the launch of Americans on the second Dragon 2 flight – odds on favorite to “Capture the Flag” left on the ISS by Atlantis’ crew – is expected to end this summer.
However, this will depend on the outcome of several major milestones, not least the initial uncrewed test flight for both commercial crew providers.
SpaceX’s Dragon 2 and Boeing’s Starliner vehicles are both contracted to return domestic crew launch capability to the United States, with SpaceX’s new vehicle first up with the DM-1 launch currently targetting NET (No Earlier Than) March 2.
A key “Agency level” Flight Readiness Review (FRR) is scheduled for next week, a milestone that will either allow SpaceX to press on with the published launch target or call for “Action Items” to be corrected before flying – an element where the FRR can result in a launch slip and potentially a second review, called a Delta FRR, to sign off on remedial work.
Starliner’s schedule is far more fluid, with its uncrewed test flight (OFT-1 – Orbital Flight Test -1) loosely scheduled for the April/May timeframe, while the CFT-1 (Crew Flight Test -1) has a placeholder in August, but may occur much later. NASA hinted at the more fluid schedule for Starliner by placing more emphasis on the “NET” nature of its dates, compared to Dragon 2’s firmer schedule.
Both vehicles also have to successfully pass another abort test flight milestone, with SpaceX set for an in-flight abort test in June while Starliner needs to achieve a successful pad abort test in NET May, which will involve a system that has been recently revamped following a major issue during testing last year that placed additional strain on its schedule.
Even if all milestones pass with flying colors, natural schedule stretch is almost inevitable. As such, NASA risks a period of time where no US astronauts are being transported to the ISS, resulting in this week’s action to press forward with recommendations that call for the purchase of at least two more seats on the Soyuz.
“Past experience has shown the difficulties associated with achieving first flights on time in the final year of development. Typically, problems will be discovered during these test flights. The consequences of no US crew on ISS warrant protection by acquiring additional seats. The absence of U.S. crewmembers at any point would diminish ISS operations to an inoperable state,” noted a procurement document published on February 13.
“NASA is considering contracting with the State Space Corporation “Roscosmos” for these services on a sole source basis for two (2) Soyuz seats and associated services to the International Space Station (ISS) on the Russian Soyuz spacecraft vehicle. This transportation would be for one crewmember in the Fall of 2019 and one crewmember in the Spring of 2020.”
The two seats in Fall 2019 and Spring 2020 seem to be in reference to the Soyuz MS-15 and MS-16 flights. Soyuz MS-15 currently has its third seat occupied by a paying spaceflight participant – who will now likely be bumped to accommodate a permanent US Station crewmember – and Soyuz MS-16 is a schedule two-person flight with a vacant third seat available.
While the action does not point to an increase in uncertainty over the progress being made by Commercial Crew providers, it does cite the wish to avoid placing schedule pressure on the companies, an issue that still haunts NASA after it was determined to have played a direct role in the loss of Shuttle Challenger in 1986.
“This Soyuz seat procurement ensures uninterrupted access to the ISS in the event of a delay in U.S. commercial crew launches, mitigating the significant risk to ISS safety and operations that the absence of U.S. crew members at any point in time would cause. Obtaining this Soyuz transportation provides flexibility and back-up capability without adding unnecessary schedule pressure to our US commercial crew providers,” added the document.
“The Aerospace Safety Advisory Panel has recommended that NASA should provide additional back-up capability in case US crew flights are delayed. This will also ensure that NASA is meeting its own needs for crew transportation as well as its obligations to the International Partnership. Ten months from now, December 2019, there will no longer be a USOS presence onboard ISS unless action is taken. These two seats would allow for US crew presence on ISS through September 2020.”
As such, the purchase is almost certain to be approved, even with hope there won’t be any serious delays in the upcoming Commercial Crew Program schedule. This would allow for the action to become a prudent overlap in capability, as opposed to a temporary replacement of launch access to the Station.
“Based on the current status of the US commercial program this date should allow overlap in capability and protect for continued ISS operation. Overlap with US commercial crew capability is required to allow smooth and safe transition to a new US capability,” NASA added.
“Even after US crew transportation completes its test program, history has shown that developing an operational cadence of flights is difficult. Launch delays will occur. This overlap in crew transportation capability provides assurance of continuous safe operation and research activity on ISS.”
While the Russians are the only crew launch provider to the ISS, Government rules require NASA to issue the synopsis to determine whether any other potential sources have the current capability to provide these crew transportation services in the required timeframes.
That requirement saw the addition of an almost comical request for “other interested organizations” to write to Government by February 28, which incidentally points to the pace at which NASA is expecting to press forward with the purchase of the Soyuz seats at a price point that is unlikely to be published.
Meanwhile, the next Soyuz launch – Soyuz MS-12 – passed its Flight Readiness Review (FRR) on Friday, ahead of its March 14 launch to the ISS.
This launch will see Russian cosmonaut Alexey Ovchinin and NASA astronaut Nick Hague make another attempt to reach the ISS, following their aborted Soyuz MS-10 launch. They will be joined by first-time flyer Christina Koch.