Delays by Boeing and SpaceX in getting their space capsules ready to fly may mean the International Space Station orbits Earth for at least nine months with no Americans on board, government auditors warned this month.
The station is an orbiting research laboratory, and the round-the-clock operations center at the Marshall Space Flight Center in Huntsville, Ala., coordinates all the U.S., European, Japanese, and Canadian experiments on board.
The U.S. Government Accountability Office (GAO) issued its latest report on NASA's Commercial Crew Program July 11. The headline was direct: "Plan Needed to Ensure Uninterrupted Access to the International Space Station."
Meanwhile, Vice President Mike Pence - and possibly President Trump himself - are planning to visit Kennedy Space Center in Florida Aug. 3 to announce the first crews that will fly on those private ships.
NASA hasn't been able to fly astronauts itself since retiring the space shuttle in 2011. Instead, it has been paying Russia to ferry its astronauts to space while awaiting the commercial ships.
But America only has seats booked on Soyuz rockets through 2019. And buying more seats isn't an option, partly because Russia can't build another Soyuz in time.
According to the GAO report, Boeing can't get its CST-100 Starliner ready for NASA's certification until January 2019. SpaceX can't get its Dragon 2 capsule ready for certification until February 2019.
Certification is the formal process NASA will use to make sure each company's capsule meets safety requirements. But it's not the end of the process. Two test flights - one without crew, one with crew - will follow the certifications.
NASA has given Boeing nearly $4.2 billion and SpaceX nearly $2.7 billion to get the ships ready. Both were supposed to have the ships ready for certification by 2017. Delays like this aren't unusual in space programs, which the auditors note are "highly complex, specialized and often pushing the state of the art in space technology."
The GAO report spells out the problems each company is having. Boeing is working to fix a risk in the "abort system" that would get astronauts off the booster rocket if something goes wrong, with the parachute system that is part of that abort system, and with data about the Atlas V rocket that will lift its capsule into space.
SpaceX has been dealing with engine turbine cracks and redesigning a part involved in a mishap in 2016. The company's biggest challenge may be getting approval to fuel the launch vehicle with the astronauts already on board.
Both contractors "are aggressive" in working the challenges, the inspectors said, but "the earliest and latest possible completion dates for certification ... indicate it is possible that neither contractor would be ready before August 2020, leaving a potential gap of access of at least nine months."
The GAO report said NASA believes having astronauts on the station continuously "is essential to maintain and operate integral systems, without which the ISS cannot function." So, the space agency is working on options that include:
* Changing the current Soyuz launch schedule to allow for a return in January 2020 instead of the planned November 2019. That would provide an extra two months of access before commercial flights need to start.
* Using the companies' crewed test flights as operational flights and sending them to the station.