The next rover that NASA plans to send to Mars in 2020 has a big job to do: gather and prepare samples from the Red Planet that can eventually be returned to Earth. It’s the first step toward a coveted “Mars sample return” — one of the highest priorities in the planetary science community right now. The only problem? There is no second step planned. Currently, the space agency doesn’t have a procedure for getting these samples off Mars and back to our own planet.

That’s a huge problem, according to the Planetary Society, which released a white paper today analyzing the current state of NASA’s Mars Exploration Program. It’s the space agency’s long-term initiative to explore the Red Planet with satellites, rovers, and landers. However, the paper, titled “Mars in Retrograde,” paints a fairly bleak picture of the program’s future. After suffering underinvestment over the past decade, the program has seen cutbacks, such as the cancellation of a few planned missions. And essentially, NASA’s exploration of Mars comes to a halt after the Mars 2020 rover, since there are no official follow-up missions in the works.

There are no official follow-up missions in the works

The Planetary Society argues that now is the time to start developing new missions to Mars if we want to keep up the amazing science that the US has done at the planet. To continue our study of Mars, we’re going to need a new orbiter to provide communication capabilities, as well as a vehicle to get any future samples off of Mars. And since planetary missions take many years to come to fruition, we’d need to get started on these vehicles sooner rather than later in order to have them ready in the mid-2020s or 2030s.

For now, though, it looks increasingly likely that these new missions could fall by the wayside. The president’s 2018 budget request for NASA doesn’t call for the development of any new Mars mission — and it may be difficult to start anything new in the future, too. NASA is facing flat budgets for the next five years, without any adjustments for inflation, according to a report in Space News. So the funds for new vehicles may be scarce. The Planetary Society says if that’s the case, we could be facing a significant gap in US exploration of Mars in the decades to come.

“Right now we are unconsciously setting ourselves up for a very difficult Mars program in the 2020s, because of all these immediate needs,” Casey Dreier, director of space policy at the Planetary Society, tells The Verge. “We don’t want to have a problem where we’ve prepared these samples and then they just rot on the ground because we’re unable to commit to bringing them back.”

Dreier argues that, above all, the most immediate need is the development of a new Mars telecommunications orbiter. Any future spacecraft we send to the Red Planet is going to need a way to communicate with mission teams on Earth. Right now, NASA has three operational satellites orbiting Mars, but only two — the Mars Reconnaissance Orbiter and Mars Odyssey — are primarily used for telecommunications. And these vehicles are getting old. Both orbiters have been at Mars for more than a decade and have lasted much longer than the span of their primary missions. By the time spacecraft are sent to retrieve samples from Mars, these satellites may have broken down and have stopped functioning. There are other orbiters circling Mars, operated by NASA and other space agencies, but these satellites are primarily aimed at doing science, and their orbits make them ill-suited for telecommunications, according to the Planetary Society.

It’s not just a Mars sample return vehicle that could use a new telecommunications orbiter, either. Basically any spacecraft that is sent to Mars is going to need a way to communicate with Earth. Currently, NASA is focused on sending people to Mars in the 2030s, but developing a new orbiter would put in place key infrastructure for a number of missions that NASA hopes to complete on and around the planet.

“The ideal timeframe for an orbiter to start is yesterday.”

NASA has been studying a number of new orbiter concepts, but the Planetary Society says it’s time to commit to a design as soon as possible. “The ideal timeframe for an orbiter to start is yesterday,” says Dreier. In order to have an orbiter ready to launch by 2022 or 2024, funding needs to be included in the budget for fiscal year 2018. That’s still possible — though the president’s budget request has already been released, NASA’s final annual budget is decided by Congress later in the year. So there is potentially still time to include a new mission, even if, as Dreier says, funding ideally should have been provided in 2017.

Beyond a new orbiter, the Planetary Society says NASA should at least start to figure out how to create a vehicle that can get samples off the Red Planet. And that’s going to be a monumental task. A Mars sample return is going to require a vehicle that can land on Mars and then take back off again, and somehow, the samples will need to be transported to that vehicle while it’s on the surface.

Of course, there are still a lot facets of NASA’s policy that need to be decided, so these concerns may not make the top of the list. The space agency still doesn’t have a permanent administrator, and, at some point, a National Space Council will be formed to help decide the nation’s space policy. It’s still unclear the exact direction this administration wants to take NASA, too. Perhaps the agency could be directed to shift its focus from Mars to another destination. Still, the Planetary Society hopes to make policy makers aware of these problems now, in order prevent a potential gap in exploration moving forward. “We just want people to be conscious that this is a decision that needs to be made and not have it be one that’s made for us by inattentiveness,” says Dreier. “There are lots of immediate problems [at NASA], but this is an immediate problem that has longer term consequences. We’re trying to raise awareness so that we can help this decision right now.”