The International Space Station got a new room on Saturday when the first inflatable structure was installed to the orbital laboratory 400 kilometers above the Earth.

Controllers in mission control at NASA's Johnson Space Center in Houston first removed the Bigelow Expandable Activity Module (BEAM) from the back of the SpaceX Dragon spacecraft, using the station's huge robotic arm.

Then, they moved the BEAM into a position next to the Tranquility module's assembly port, where NASA astronauts aboard the station secured it using common berthing mechanism controls.

The BEAM was attached to the station at 5:36 am ET (0936 GMT), a huge step for expandable habitats in space and NASA's "Journey To Mars" program, NASA tweeted after a nearly three-and-a-half-hour installation.

The BEAM, built by Bigelow Aerospace and NASA, was launched aboard Dragon on April 8 from Cape Canaveral in Florida. NASA said it may help inform the design of deep space habitats.

At the end of May, the module will be expanded to nearly five times its compressed size of 7.75 feet (2.4 meters) in diameter by 5.7 feet (1.7 meters) in length to roughly 10.5 feet (3.2 meters) in diameter and 12 feet (3.7 meters) in length.

Astronauts will first enter the habitat about a week after expansion and, during a two-year test mission, will return to the module for a few hours several times a year to retrieve sensor data and assess conditions, the U.S. space agency said.

Inflatable habitats are designed to take up less room on a rocket, but provide greater volume for living and working in space once expanded.

This first test of an inflatable module will allow investigators to gauge how well the habitat performs overall and, specifically, how well it protects against solar radiation, space debris and the temperature extremes of space.

Once the test period is over, the BEAM will be released from the space station, and will burn up during its descent through Earth's atmosphere, NASA said.