Businesses can now rent one of NASA’s simulators at Johnson Space Center.

NASA’s Neutral Buoyancy Lab, a super-sized swimming pool four-stories deep, simulates space for astronauts to train. It is so big a full-size International Space Station replica fits inside.

Now, it is available to rent. A NASA YouTube video even boasts, “We’re now open for business, your business.”

“Certainly the economics of it makes a lot of sense,” said Todd Probert, vice president of Raytheon.

Probert’s company runs and maintains the lab. They employ 120 people there. The pool is monitored 24 hours a day, seven days a week.

“For those of you who have a backyard pool, that’s considerable maintenance in its own right,” Probert said. “To maintain this pool, we have to worry about those same considerations on a bigger scale.”

So, it is hardly cheap. With no shuttle program program and fewer astronauts sent into space, NASA let oil and gas companies dive in a few years ago.

Instead of spending $100,000 on emergency underwater training in the Gulf of Mexico, some pay about $25,000 to do it in the lab. Engineers there build anything clients need. Some groups even bring underwater vehicles.

The money made helps NASA keep things afloat.

“Spreading it out over as many users as you possibly can makes a lot of sense from an economic standpoint,” Probert said. “So there’s a practical application to what NASA’s trying to do here.”

Astronauts from around the world still use the pool to prepare for missions three to four times a week and six hours a day.

However, NASA insists there’s room for much more.