Recently named the best place to work in the federal government for the fourth year in a row, NASA is looking for the best candidates to work in the best job on or off the planet. The astronaut candidate application website now is live and accepting submissions through Feb. 18.

The agency expects to announce final candidate selections in mid-2017. Those chosen may fly on any of four different U.S. spacecraft during their careers: the International Space Station, two commercial crew spacecraft currently in development by U.S. companies, and NASA's Orion deep-space exploration vehicle.

"NASA is on an ambitious journey to Mars and we're looking for talented men and women from diverse backgrounds and every walk of life to help get us there," said NASA Administrator and former astronaut Charles Bolden.

"Today, we opened the application process for our next class of astronauts, extraordinary Americans who will take the next giant leap in exploration. This group will launch to space from U.S. soil on American-made spacecraft and blaze the trail on our journey to the Red Planet."

NASA astronauts will again launch to the International Space Station from Florida's Space Coast on American-made commercial spacecraft - Boeing's CST-100 Starliner and the SpaceX Crew Dragon.

These spacecraft will allow NASA to add a seventh crew member to each station mission, effectively doubling the amount of time astronauts will be able to devote to research in space, expanding scientific knowledge and demonstrating new technologies.

Astronauts also will lift off again from NASA's Kennedy Space Center in Florida aboard the Orion spacecraft, launched on the agency's Space Launch System rocket, to unprecedented missions in lunar orbit.

There, the space agency will learn more about conducting complex operations in a deep space environment before moving on to longer duration missions as it progresses on its journey to Mars.

To help accomplish this work, NASA will select qualified astronaut candidates from a diverse pool of U.S. citizens with a wide variety of backgrounds, including engineers, scientists and physicians.

According to the professional networking site LinkedIn, some 3 million of the site's members working in the United States appear to meet the minimum academic eligibility requirements for the job.

"NASA's mission, and what we need from the astronauts helping to carry it out, has evolved over the years," said Brian Kelly, director of Flight Operations at NASA's Johnson Space Center in Houston.

"Some people would be surprised to learn they might have what it takes. We want and need a diverse mix of individuals to ensure we have the best astronaut corps possible."

Astronaut candidates must have a bachelor's degree from an accredited institution in engineering, biological science, physical science, computer science or mathematics. An advanced degree is desirable.

Candidates also must have at least three years of related, progressively responsible professional experience, or at least 1,000 hours of pilot-in-command time in jet aircraft. Astronaut candidates must pass the NASA long-duration astronaut physical.

"The Office of Personnel Management is proud to support NASA's efforts to recruit our country's next generation of astronauts," said Beth Cobert, acting director of OPM. "One of this agency's primary goals is to help attract, recruit, hire and retain the best and most talented workforce to serve the American people.

"We stand ready to help NASA find and support the talent it needs to fulfill its exciting mission to Mars. I'm proud to help agencies across government shape the federal workforce of the future by providing such tools as USAJOBS, our one-stop source for federal job and employment information."

+ Qualifying U.S. citizens may apply here

+ Follow NASA on LinkedIn, and find more NASA jobs here