Astronaut training has resumed at an undersea laboratory in the Florida Keys.
Starting Tuesday, five astronauts will spend five days living and working at the Aquarius Reef Base. While they're underwater, they'll be trying out an exercise device that could be used on the International Space Station and spacewalking tools.
The federal government owns the pressurized lab that sits about 60 feet below the ocean's surface a few miles off Key Largo. Florida International University took over its operations in January.
Astronauts last trained at Aquarius in June 2012 when it seemed like federal budget cuts would close the lab.
NASA officials say the lab's watery environment is similar to a low earth orbit. That allows astronauts to field test their skills for space expeditions.