The first expandable room was installed at the International Space Station.

Installation for the Bigelow Expandable Activity Module, also known as BEAM, began around 2 a.m. Saturday.

It’s an expandable habitat that astronauts will use for about two years to see how well it protects against solar radiation, space debris and contamination.

The expansion of the new module won’t take place until next month, according to NASA. BEAM will be filled with air to expand nearly five times its compressed size.

It’s a significant breakthrough for the space agency, which says BEAM is crucial for future deep space exploration.

Once astronauts are done with it, BEAM will burn up as it descends through Earth’s atmosphere.

Check out video of the installation here.