ROBERT SIEGEL, HOST:

Last December, NASA asked people if they wanted to be astronauts. The overwhelming answer was yes.

ANNE ROEMER: We had a record number of applications - roughly 18,300.

SIEGEL: That's Anne Roemer, the astronaut selection manager at NASA. She credits NASA's social media campaign to nearly tripling the number of applicants since the last time it recruited astronauts.

AUDIE CORNISH, HOST:

But NASA is looking for, like, 14 astronauts, max. Roemer says applicant who don't have the required science background will get weeded out first.

ROEMER: Then the Astronaut Rating Panel will come in, and then they will have the difficult task of then narrowing down the candidate pool and discerning who the highly qualified candidates are.

SIEGEL: Maria Banks was told that she was highly qualified the last time she applied, but she didn't get picked. She has no regrets, as she told NPR back in December.

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MARIA BANKS: A lot of people were almost afraid to ask me, you know, oh, what happened? Did you get rejected? You know, they thought that that would be a bad question. But it was such a fun journey, and I definitely saw this as an achievement of mine even though I didn't reach my final goal.

SIEGEL: Now the planetary scientist is one of the thousands of hopefuls in this round. She's already explored much of this world, but there's one thing that she's dying to do.

BANKS: I can't walk on the surface of another planet just now. I try to do that as best I can using data and images sent back from the Rovers and the Landers and, of course, orbiting spacecraft.

CORNISH: She'll have to be patient. NASA expects to make its decision by summer of 2017. Transcript provided by NPR, Copyright NPR.