Robb Kulin becomes the first astronaut candidate to resign in 50 years, officials from NASA confirmed on Monday, Aug. 28.

Astronaut Candidate Resigns From NASA 2017 Class

The 35-year-old did not comment when his early retirement was announced to the public, but the space agency said that the aspiring astronaut was leaving for "personal reasons."

Kulin, a native of Alaska, is one among the 12 people selected in the astronaut class of 2017. He bested 18,300 other applicants — a record-breaker for the agency.

NASA said that it will not replace Kulin from the program, leaving the 2017 class with just 11 members. Kulin's resignation will be effective on Aug. 31, a little over a year after he entered the two-year astronaut training at the Space Center in Houston.

Kulin is the first astronaut candidate to resign before qualifying for spaceflight since 1968. That year, two astronauts, Bryan O'Leary and John Llewellyn, left due to "lack of spaceflight prospects" and for "failing to make progress piloting jets" respectively.

Prior to joining the class of 2017, the astronaut candidate worked as a senior manager for flight reliability at SpaceX. He primarily worked on the Falcon 9 rocket.

Kulin has a Bachelor's degree in Mechanical Engineering from the University of Denver. He also pursued a Master's in Materials Science and earned a Doctorate in Engineering from the University of California, San Diego.

He has experience working as an ice driller on the West Antarctic Sheet and Taylor Glaciers in Antartica and as a commercial fisherman in his hometown of Alaska. He is also a private pilot.

In a previous interview with Space, Kulin said that he wanted to see humanity become an interplanetary species. He talked about landing and eventually colonizing Mars.

"There's a lot to be learned even about our own planet here on Earth by going out and exploring other places and having that kind of ability to reflect back," he explained. "But I actually think Mars will be kind of the most incredible next journey for the human exploration side."

Astronaut Training

NASA's astronaut corps has over 40 active members led by Patrick Forrester. Inclusion into the program does not guarantee that a candidate will be an astronaut and sent to outer space.

To be a NASA astronaut, candidates must successfully complete the basic training program. To graduate from the program, aspiring astronauts must pass International Space Station systems training, Extravehicular Activity skills training, Robotics skills training, Russian language training, and aircraft flight training.

ⓒ 2021 All rights reserved. Do not reproduce without permission.