He's accomplished something no other American astronaut has ever done, and now, just two weeks after his return to Earth from his historic "Year in Space," New Jersey native Scott Kelly says he will retire from NASA.

"NASA astronaut and one-year crew member Scott Kelly will retire from the agency, effective April 1. Kelly joined the astronaut corps in 1996 and currently holds the American record for most time spent in space," NASA said in a statement on the agency's website Friday.

Despite his plans to retire, NASA says the astronaut - a West Orange native - will continue to participate in medical tests along with his twin brother, astronaut Mark Kelly, that coincided with his yearlong mission aboard the International Space Station.

“This year-in-space mission was a profound challenge for all involved, and it gave me a unique perspective and a lot of time to reflect on what my next step should be on our continued journey to help further our capabilities in space and on Earth,” Kelly said in a statement to NASA. “My career with the Navy and NASA gave me an incredible chance to showcase public service to which I am dedicated, and what we can accomplish on the big challenges of our day. I am humbled and excited by new opportunities for me to support and share the amazing work NASA is doing to help us travel farther into the solar system and work with the next generation of science and technology leaders.”

Kelly returned to Earth on March 1 and holds the record among U.S. astronauts for cumulative time in space, with 520 days aloft, according to NASA. Kelly’s mission was years in the making, and the journey itself was historic in several ways, from the medical testing he and his twin brother conducted to experiments aimed at preparing for an eventual mission to Mars.

According to NASA, Kelly flew in space four times. His first mission was the space shuttle Discovery’s trip to the Hubble Space Telescope on the STS-103 servicing mission in 1999. He then joined mission STS-118 as commander of space shuttle Endeavour, at which point he made his first trip to the International Space Station. In 2010, he returned to the ISS for six months as the commander of Expedition 26. His fourth mission was his historic Year in Space.

In addition, Kelly become an Internet celebrity, of sorts, with more than 1 million followers and tweets to and from celebrities and political dignitaries including president Barack Obama. Followers looked forward to his #YearInSpace and #EarthArt pictures on Twitter and Facebook, depicting colorful images of the earth as seen from space. He’s even tweeted pictures from above the Super Bowl as well as images of major storms including the recent January blizzard that dumped roughly two feet of snow on some areas of the state.

Since his return to Earth, Kelly has been honored by various officials including NJ Sens. Cory Booker and Robert Menendez.

“This resolution honors his outstanding contribution to science and exploration in the name of international cooperation. I am extremely proud to welcome this fellow New Jerseyean and lover of science home and I congratulate him on his record-breaking voyage," Booker said in a statement on March 3.

As he continues to acclimate to life on the planet and his current home state of Texas, Kelly continues to tweet about his #YearInSpace and his return to Earth.

Toniann Antonelli is the digital managing editor for news at NJ 101.5. Reach her at toniann.antonelli@townsquaremedia.com, or on Twitter @ToniRadio1015.