It’s no secret that the International Space Station has an expiration date. The only variable is how it’ll be brought down to Earth. NASA has now tapped SpaceX for the mission and is paying the company $843 million to bring the ISS back safely.

SpaceX, a private space enterprise company owned by Elon Musk, will use the money from the NASA contract to build a deorbit vehicle. NASA will then tap a contractor to launch that vehicle into space to dock with the ISS. The final step in the plan is to have the vehicle slowly deorbit the ISS in such a way that it falls back to Earth in an unpopulated area, where it can be safely recovered without harming anyone.

SpaceX said it’s “honored to be trusted by NASA to support this critical mission,” in a post Wednesday on X.

“Selecting a US Deorbit Vehicle for the International Space Station will help NASA and its international partners ensure a safe and responsible transition in low Earth orbit at the end of station operations,” Ken Bowersox, associate administrator for Space Operations Mission Directorate at NASA Headquarters, said in a statement. “The orbital laboratory remains a blueprint for science, exploration and partnerships in space for the benefit of all.”

NASA says a second contract will be awarded in the future to launch the deorbit vehicle into space once it’s built. Since SpaceX has quite a bit of experience in launching things spaceward — like satellites to provide broadband and manned missions to the ISS — it’s possible the company will also be granted that contract.

When is the ISS set to come back to Earth?

The ISS is scheduled to retire in 2030, which is also when it’s set to come back to Earth. It’ll be busy up until its retirement. NASA plans to transition the space station into a commercial operation over this decade to let companies use it before it’s retired. (The ultimate goal is for private companies to have low Earth orbit installations that don’t have to be maintained by NASA.)

Otherwise, the ISS has lived a full life. The construction missions started in 1998, and the ISS has been continuously manned for the last 22 years.

Why is the ISS being deorbited?

NASA says the structure’s finite life-span is due to thermal cycling; wear from the dockings and undockings of spacecraft; and other factors.

In short, NASA says that after 2030, the ISS simply won’t be safe enough for humans to be there.

How will the space station be brought down?

It’s simpler than you might think. According to NASA, the US deorbit vehicle being built by SpaceX will dock with the ISS. From there, the vehicle will use its propulsion system to push the ISS into a lower orbit.

After that, the drag from Earth’s atmosphere will take over and bring the ISS back to Earth. The controlled deorbit procedure will be calculated so that the ISS’ debris will fall into the ocean where it can’t hurt anyone.

Why is NASA using a deorbit vehicle?

Other potential methods to get the ISS out of space are either too difficult, too expensive or both. NASA considered deconstructing the ISS and bringing it back piece by piece. However, the agency says that the original assembly took 27 flights by NASA and that disassembly might take even more due to the ISS being more difficult to deconstruct than it was to build.

Another option was to boost it to a higher orbit so that it could join the Great Garbage Shell that already exists in space. NASA says the issue with that approach is that it would take too much propellant to lift the massive space station into a “graveyard orbit.” The current capabilities of the ISS could increase its orbit slightly, but it would remain in low Earth orbit without additional, costly assistance.

The third option considered was to let it simply fall out of space on its own. Of course, the issue there is fairly self-explanatory: If the ISS falls out of space on its own, NASA won’t be able to control where it lands. That means it could land in a populated area and harm people.