For 50 years, NASA has followed a rigorous set of guidelines to prevent the contamination of other worlds while exploring the Solar System — but it may be time those guidelines got an update. That’s according to a new report from National Academies of Sciences, Engineering, and Medicine, which did a thorough review of NASA’s policies for limiting interplanetary contamination. The organization says that NASA’s much more complex space missions and a rapidly expanding private space industry demand new sets of rules, as well as a better process for implementing them.

This concept of preventing biological contamination of the Solar System is known as planetary protection. The goal is to limit the amount of microbes we send to other planets, so we can study these worlds in their natural environments. Also, if we find life off of Earth, we’ll know that we didn’t put it there ourselves. Planetary protection involves more than just protecting other planets, though. The policy is also meant to prevent NASA or other space agencies from bringing back any unforeseen alien bugs back to Earth that might cause some nasty, unstoppable pandemic. So whether you’re sending a spacecraft to another world or bringing back rocks from a distant moon, you need to abide by established planetary protection guidelines.

The legal basis for planetary protection stems from a more than 50-year-old document known as the Outer Space Treaty, which has been ratified by 105 countries, including the US. However, the treaty is pretty vague on details. It really only says that nations must avoid the “harmful contamination” of space and prevent “adverse changes in the environment of the Earth resulting from the introduction of extraterrestrial matter.”

As for specific ways to prevent contamination — such as the preferred methods for cleaning germs from spacecraft — NASA tries to adhere to a set of guidelines set out by an international organization called COSPAR, or the Committee on Space Research. This committee releases detailed rules for how to clean spacecraft and what type of processes vehicles have to go through depending on where they’re going in the Solar System. NASA has its own small office, helmed by a planetary protection officer, that ensures the space agency is sticking to COSPAR guidelines. However, the COSPAR rules are not legally binding, so NASA does not have to follow them.

The authors of the National Academies of Sciences report say these planetary protection procedures have worked well for the last half century, but times are changing. For one, NASA is about to undertake more complicated space missions than it ever has done before. It’s planning on sending a spacecraft to Jupiter’s moon Europa to fly through possible plumes of water to look for signs of life. And the space agency is sending a new rover to Mars in 2020 to dig up samples that may be one day returned to Earth for study. “NASA is undertaking much more complex science missions than in the past, and at the same time they’re having to operate under cost restraints and schedule restraints,” Scott Hubbard, professor of aeronautics at Stanford and one of the lead authors of the report, tells The Verge. “These missions bring up all sorts of issues about possible contamination, both going there and bringing samples back.”

Meanwhile, NASA has long talked about sending humans to the Red Planet — and people are extra messy creatures. Crews would bring a lot of microbes to Mars, and NASA would need an entirely new framework for what is considered acceptable contamination when that happens.

Plus, the space agency isn’t the only one that wants to send people to Mars, either. Private company SpaceX is also focused on starting its own Mars colony, and it’s getting closer to actually making such a monumental task a reality. The company launched a Tesla roadster near the orbit of Mars earlier this year, and SpaceX CEO claims its next big rocket, the BFR, will be ready for early testing by next year. That’s another reason the authors say we need updated guidelines: the private space industry is growing more capable and more ambitious in its exploration of the Solar System. As more actors emerge in the field, we’ll need a way to make sure everyone is following the same rules. “We have a whole new set of players like SpaceX,” says Hubbard. “We’ve got entrepreneurs capable of reaching Mars, but how will you supervise them?”

All of these factors are why Hubbard and his co-authors say it’s time for NASA to come up with a new strategic plan for planetary protection. First, NASA needs to do a more rigorous job of writing down all of its planetary requirements and implementing these policies equally. That way, there’s no confusion over what is required, potentially preventing disagreements between those running the mission and the agency’s planetary protection officer.

The authors say NASA also needs to get more advice from outside experts, such as microbiologists and geneticists, about what kinds of microbes are resilient and problematic for interplanetary spacecraft. NASA also needs to invest more in technology and research regarding cost-effective vehicle cleaning, the report argues. Additionally, the report claims that NASA should create a really long-term roadmap of all the missions that are coming up and what protocols are needed for each trip well in advance. “One of the problems we noted is that these planetary protection requirements tend not to be developed until the mission is already underway or getting started,” says Hubbard.

The last recommendation concerns equality: there needs to be a way for these guidelines to be applied equally to NASA missions and to private sector missions. This bit is tricky, though, as the US government will need to step in. “We’re very clear that whatever new planetary protection strategic plan is developed for NASA needs to be applied equally to private endeavors, but you need legislation to make that happen,” says Hubbard.

Along with laying the groundwork for planetary protection, the Outer Space Treaty also addresses something called continuing supervision. Basically, governments will be held responsible for whatever their private companies do in space. But that’s an issue right now, as the US government doesn’t currently have any framework for overseeing what the private sector does in space. It’s a regulatory gap that’s been plaguing the US for the last decade, and it will need to be filled in order to ensure companies don’t violate the US’s treaty obligations.

A solution may be on the way soon. The Trump administration wants the Commerce Department to take on the job of overseeing ambitious space activities from private companies. And there is a bill making its way through Congress called the American Space Commerce Free Enterprise Act that would give the Commerce Department oversight. However, that bill still needs to pass the Senate, and it doesn’t go very far in addressing how the Commerce Department would ensure companies stick to planetary protection guidelines.

Ultimately, Hubbard hopes a new version of the bill or future legislation might address this problem and detail how companies will keep their deep space vehicles clean. He foresees NASA providing all the technical details of planetary protection to the US government, and the government would then issue licenses to companies when they’ve proven they’ve met all the necessary requirements. Hubbard hopes some kind of regulatory solution is decided soon, since the industry is rapidly moving forward. “All of this is imminent, so I see a real near-term pressure for Congress to take action and for NASA to do its job within the agency,” he says.