Who is Mark Kelly? What to know about astronaut career of censured senator

• Sen. Mark Kelly, a former NASA astronaut, was censured by Pentagon chief Pete Hegseth.
• Before his political career, Kelly was a Navy fighter pilot and flew four space shuttle missions.
• Kelly's identical twin brother, Scott Kelly, is also a retired NASA astronaut.

Before he found himself a target of the Trump administration as a U.S. senator, Mark Kelly was a veteran NASA astronaut who flew to space on four separate missions in a decade.

Sen. Kelly, D-Arizona, was recently issued a formal censure courtesy of Pentagon chief Pete Hegseth for his role in a video telling service members they "can refuse illegal orders." Kelly was first elected to office in 2020, about nine years after he retired from both the Navy and NASA.

Prior to his career as a public servant, Kelly, 61, was a Navy fighter pilot who saw combat and also an astronaut who piloted – and even commanded – space shuttle missions to orbit.

Here's everything to know about Mark Kelly's astronaut career with NASA.

Pete Hegseth censures US Senator Mark Kelly

Hegseth's censure of Kelly, announced Monday, Jan. 5, on X, comes after the Arizona senator became one of six Democratic lawmakers who drew the Trump administration’s ire by recording a video in November telling service members they “can refuse illegal orders.”

Hegseth, the defense secretary, had originally threatened to court-martial Kelly, a retired Navy captain, before opting for a formal censure and initiating proceedings aiming to demote Kelly in retirement.

In response, Kelly blasted Hegseth in a statement posted to X, calling him "the most unqualified Secretary of Defense in our country’s history."

Mark Kelly is a retired NASA astronaut

Kelly, a formal naval officer who flew 39 combat missions in Operation Desert Storm, was selected in 1996 to train to become a NASA astronaut.

Kelly ultimately retired from both the Navy and NASA in 2011 – the same year that his wife, Gabby Giffords, a former Democratic congresswoman from Arizona, was shot and nearly killed in an attempted assassination. He was first elected in 2020 as a U.S. senator.

Kelly has traveled on space shuttles, been to International Space Station

During his astronaut career, Kelly flew on four NASA space shuttle missions between 2001 and 2011, spending a total of 50 days in space and traveling more than 20 million miles, according to his senate biography.

Kelly's final spaceflight in 2011 to the International Space Station was also the last for Endeavor – one of the shuttles under NASA's now-iconic program to transport crew and cargo from Earth to orbit. For three decades, the shuttles flew 135 missions critical to helping astronauts reach space, constructing the ISS and launching, recovering and repairing satellites.

Mark Kelly's twin brother Scott Kelly is also a NASA astronaut

Kelly was initially selected as an astronaut in the same NASA class as his identical twin brother Scott Kelly.

Scott Kelly, also a retired naval aviator, flew on four missions of his own between 1999 and 2015 ‒ the last of which helped etch his name in NASA history. In March 2016, Scott Kelly and Russian cosmonaut Mikhail Kornienko returned from a nearly yearlong mission at the International Space Station, where they spent 340 days in low-Earth orbit.

At the time, the mission gave Scott Kelly the record for the NASA astronaut with the most consecutive days in space. The record has since been surpassed by NASA astronauts Mark Vande Hei and Frank Rubio – who spent 355 days and 371 days in space, respectively.

Contributing: Davis Winkie, USA TODAY

Eric Lagatta is the Space Connect reporter for the USA TODAY Network. Reach him at [email protected]