Why the ESA’s Astronauts Train Underground

The European Space Agency is applying protocols from the International Space Station in caves

ESA / D. Feustel

Prospective astronauts have to undergo a battery of physical and psychological tests and survival training before they’re approved to go into space. And since 2012, the European Space Agency has added another layer to its astronaut training—a two-week crash course in speleology it calls CAVES (Cooperative Adventure for Valuing and Exercising human behaviour and performance Skills).

At first, it might seem like caves aren’t a great place to simulate space. But it turns out that the astronauts’ trip to Italy’s Sa Grutta caves is a great way to acclimate them to the complex operations of the International Space Station. In a recent blog post, researcher Raffaela Franco describes how the agency translates space ops underground.

Franco explains that caves present similarities to space flight, giving would-be astronauts a chance to communicate with their crew and control centers in ways that mimic the protocols they’d use in space. “Offering familiar protocols to astronauts could result in quicker adaptation to the new environment” says Franco, who points out that the team uses the same procedures underground as they would on the ISS.

But there’s a big difference between caves and a station hundreds of miles above ground—lack of infrastructure. The ESA’s 2014 CAVES course included far more rudimentary communications tools than the ones astronauts really use in space. For example, notes Franco, the team had to use USB sticks to transfer data rather than almost-real-time comm links. And they only had two ways to communicate with each other and their home base: a telephone cable and a wireless underground radio.

Despite these challenges, the team learned a valuable lesson during their time underground—though it’s nice to have multiple high-tech options for communication while isolated from Earth, it’s not actually necessary. In fact, says Franco, the astronauts got by without constant real-time data as long as they communicated using structures similar to the ones they’d use in space. They also learned to love good, old-fashioned paper—a lesson that will better equip the ESA for glitches and crises in the actual space station.

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