A record shattering number of submissions to become astronauts at NASA shows that the agency won’t have difficulty finding people willing to go to Mars — but does everyone who is applying know what they’re getting into?

For the first time since 2012, NASA has opened up 14 new positions for astronauts and accepted applications between December 15 and February 18. They ended up buried in applications, with 18,300 people submitting resumes, absolutely obliterating the old record of 8,000 in 1978, and eclipsing 2012’s total by three times.

Mars One, a nonprofit organization based in the Netherlands, is one of a few efforts to push for mankind to populate Mars at some point, hopefully by the 2030s. But it will take a special kind of astronaut to take the trip.

For one thing, any astronaut making this journey will have to know that it will be the final destination. There will be no return trip — anyone taking the trip will never see Earth again. That’s a tough reality for anyone to accept, and only the most adventurous and self-sacrificing individuals are likely to fit that category.

But the journey itself will be fraught with risks. There’s the launch itself, which is never a sure thing. There’s the six-month journey. There’s the delicate landing on Mars. And the most difficult aspect: surviving on the surface of Mars, complete with unbreathable air, brutally cold temperatures, and an atmosphere unable to protect them from the sun’s fierce radiation.

But at least NASA, the European Space Agency, and others have time to figure out how to keep astronauts safe. Perhaps the bigger risk won’t be physical, but rather psychological — which is what makes NASA’s selection of the right astronauts so critical.