BEAM, an inflated module for the ISS

BEAM, an inflated module for the ISS

On 28 May, NASA announced that the BEAM experimental module for the ISS had been inflated to its maximum size (16 m3). Supplied by the Bigelow company, BEAM aims to test whether such modules could be used for manned space flights.

The International Space Station (ISS) has a new module ready to accommodate astronauts, although in reality they’ll only visit for very short durations. What is it? BEAM, the Bigelow Expandable Activity Module. It was deployed (actually, inflated) in two stages on Thursday 26 and Saturday 28 May. Offering a modest volume of 16 metres cubed (the European Columbus laboratory is 75 metres cubed in comparison), BEAM is an experiment that aims to explore whether future space stations or manned spacecraft could use this technology.

BEAM - NASA - ISS

This diagram from NASA indicates BEAM’s location on the ISS. The inflatable module is docked to the Tranquillity module (Node 3), one of the modules in the American sector built by Thales Alenia Space in Italy. Image credit: NASA

Inflatable: a question of volume

In the early days of space exploration, NASA worked on the concept of an inflatable module. The primary advantage was the space saving. Indeed, in order to send a module almost 6.81 m long and 4.48 m in diameter (the dimensions of Columbus, as referred to above), you would need a launch vehicle capable of carrying the volume that this would represent. With regards the European laboratory (and the American modules of the ISS), that job fell to NASA’s space shuttle and its vast hold. With the inflatable, it could be possible to send a large module into space without being too concerned about the limits of diameter and length.

Near Las Vegas, the U.S. company Bigelow Aerospace took over the patents from the U.S. space agency to develop its own inflatable modules. It even successfully launched 2 into orbit (by purchasing the service from the Russians) in 2006 and 2007 in order to test them. Named Genesis I and II, these modules measuring 4.4 m and 2.54 m in diameter (once inflated) are still orbiting Earth. They are not inhabited but contain objects provided by people who paid for such objects to be aboard.

Wanting to learn more about the feasibility of the inflatable for manned missions, NASA signed a contract with Bigelow Aerospace to supply it with an experimental module, BEAM. It was taken to the ISS in early April by a Dragon cargo ship belonging to SpaceX.

BEAM - Bigelow - ISS

Cross-section of the BEAM module by Bigelow Aerospace. Image credit: Bigelow Aerospace

BEAM inflates in two stages

On 16 April, BEAM was captured by the Canadian robotic arm, Canadarm 2 and attached to the Tranquillity module. Then, on Thursday 26 May, its inflation procedure was started. However, there were several problems, forcing the U.S. astronaut Jeff Williams to make verifications on BEAM’s control panel. The pressure in the module (the hatch between it and the ISS is obviously closed for safety) was higher than planned and the expansion could not proceed as expected, the operation was halted.

After consulting with Bigelow Aerospace, NASA resumed the deployment of BEAM which finally reached its maximum size. The NASA video below shows a summary of the procedure.

With a mass of 1.3 tonnes, the module went from a size of 1.7 m long with a diameter of 2.4 m to 3.2 m x 4 m. The time-lapse video below shows the benefit of this technology: a module which does not initially take up its final volume can be sent into orbit. Without this trick, the inflated BEAM could never have been transported by the Dragon cargo ship which is far too small.

Now deployed, BEAM will be observed for almost 2 years. Many measurements will be taken in order to monitor how its external cover resists the harsh conditions on orbit, particularly impacts from micrometeorites, thermal stresses, radiation, etc. Inside, checks will be made to ensure that an inflatable module can meet the safety requirements of manned space flight (absence of air leaks, radiation levels, etc.). As caution demands, it is far too early for the astronauts to use it. They will enter it 3 to 4 times a year in order to conduct visual inspections to complement the measurements. Outside of these visits of a maximum of a few hours, the hatch between the ISS and BEAM will be closed. After the 2-year test, BEAM will be detached from the space station and will burn up in the upper levels of the atmosphere.

From space station to orbiting hotel

Over the longer term, if the concept of the inflatable module proves to be relevant, it is expected to be used so that more modestly-sized (and therefore less expensive) launch vehicles can be employed to send such structures into orbit. In addition to a smaller size, Bigelow Aerospace is claiming a 15 % reduction in mass compared to the conventional rigid structure.

Bigelow - NASA - NextSTEP

Two Bigelow inflatable modules (B330 type, larger than BEAM) on lunar orbit. A concept studied with NASA as part of a contract called NextSTEP. Image credit: Bigelow Aerospace

Furthermore, the U.S. company is working on concepts for inflatable habitats for lunar orbit or on the surface of our natural satellite and is open about its intention to build a private space station, or even a hotel for space tourists. After all, Robert Bigelow, the founder of the company that bears his name, made his fortune in the hotel industry. This native of Las Vegas, born in 1945 and passionate about space from childhood, is obviously seeking a less down-to-earth, but no less profitable market.

Robert Bigelow

Robert Bigelow at a press conference. A hotel magnate born in Las Vegas, he founded the space company in 1999. Image credit: Bigelow Aerospace