History was made this weekend, as the International Space Station (ISS) received its first inflatable habitat, a key technology that may one day be used for space hotels, and even missions to the Moon and Mars.

The Bigelow Expandable Activity Module (BEAM), built by Las Vegas-based Bigelow Aerospace, was launched to the ISS in the back of a SpaceX Dragon capsule on April 8. Then, on Saturday, April 16, it was removed and attached to the Tranquility module by the station’s robotic arm at 5:36 a.m. EDT (10:36 a.m. BST), a process that took more than four hours.

“The first human-rated expandable structure to be flown in space, now attached to the International Space Station,” said Dan Huot, NASA public affairs officer, reported Spaceflight Insider.

This is the first new “room” that has been installed on the ISS since Leonardo, a storage module, more than five years ago.

^{Check out a time-lapse video of the installation above.}

However, the installation of BEAM is not yet complete. The module itself was launched in a compact form, and it will not be inflated until the end of May, when it will expand to about five times its current volume. The module will expand from 2.1 meters (7 feet) wide and 2.4 meters (8 feet) in length to 3 meters (10 feet) wide and 4 meters (13 feet) in length.

It’s also not really a “true” module for the ISS, as the astronauts won’t use it for any station operations, not even storage. Instead, several sensors inside BEAM will study how it copes with being in space, measuring radiation levels, pressure, and detecting any impacts from space debris, before it is detached in two years and sent to burn up in the atmosphere.

If the tests proceed without a hitch, though, then Bigelow Aerospace has plans for bigger and better inflatable modules in the future. Most notably, they recently signed an agreement with the United Launch Alliance (ULA) to launch a larger inflatable habitat, called the B330, at some point in 2020. This habitat will either be attached to the ISS or positioned alone in a separate orbit, possibly forming the first part of a new private space station.

Further down the line, the plan is to launch multiple B330 habitats and connect them in space, creating a “space hotel” that paying tourists can go visit on one of several new private spacecraft in development. There are even discussions to use inflatable habitats on missions to the Moon or Mars in order to save space at launch.

The successful demonstration that BEAM works without any problems will be an important step towards this goal. The ISS now has a new room, and it’s one that could fundamentally change spaceflight forever.