NASA would love to stop having to rely on Russia to send its astronauts into space, but realizing that dream means that someone needs to step up to the plate with a safe, reliable crew transportation system. Right now, both SpaceX and Boeing are working independently to meet that demand, but a new report from the Government Accountability Office reveals that neither of them are as far along as they should be, and that’s not great news to U.S. astronauts.

The two companies — SpaceX with its Dragon capsule and Boeing with its Starliner spacecraft — are both under contract with NASA to develop, build, and launch commercial crew missions to the International Space Station, but assessments of the two companies’ systems reveal shortcomings that will likely delay the deployment of both.

The government report doesn’t mince words regarding how the delays could affect NASA’s science efforts as they relate to work aboard the International Space Station:

“Boeing and SpaceX continue to make progress developing their crew transportation systems, but both contractors have further delayed the certification milestone to early 2019. Without a viable contingency option for ensuring uninterrupted access to the ISS in the event of further commercial crew delays, we concluded that NASA was at risk of not being able to maximize the return on its multibillion dollar investment in the space station.”

In short, if the two companies can’t keep up with their milestones, NASA simply doesn’t have a backup plan for getting its astronauts to the space station. Meeting NASA’s demands means proving beyond a shadow of a double that the manned spacecraft are capable of safely delivering astronauts to the ISS, and neither company has come close yet.

As SpaceX has clearly demonstrated over the past decade, building new spaceflight systems is incredibly challenging. The company has celebrated its failures in the past as learning experiences, but things change dramatically when human lives are on the line. It’s obviously crucial that both companies get things right, and if delays mean safe travel in the future, it’ll be worth the wait.