CAPE CANAVERAL, Fla. (CBSDFW.COM/AP) — For the first time in 50 years, an astronaut-in-training is quitting NASA.

Astronaut candidate Robb Kulin has resigned halfway through his two years of training at Johnson Space Center in Houston. A NASA spokeswoman says his departure is effective Friday and that he is leaving for personal reasons that the space agency cannot discuss due to privacy laws.

robb kulin Astronaut Quits Halfway Through Training, 1st In 50 Years

Astronaut candidate Robb Kulin has resigned halfway through his two years of training at Johnson Space Center in Houston. (photo credit: NASA)

Kulin, 34, was among 12 new astronauts chosen last summer from a record 18,300 applicants. An Alaskan native, Kulin was working as a senior manager at SpaceX when selected and said at the time he was hoping to fly on a vehicle he helped design. SpaceX and Boeing are developing NASA’s first commercial crew capsules, due to launch within the next year.

The last time astronauts-in-training resigned from NASA was in 1968.

Johnson Space Center is about 250 miles from DFW.