Mark Kelly

Mark Kelly’s life story could be told as a fairy tale, as science fiction, as a romance novel, or as a tale of political intrigue. It is all of those things—and then some.

At its most basic, Kelly’s story is that of a suburban kid who grew up to be an astronaut, marry a congresswoman, and be elected to the U.S. Senate. But layer in the facts that he has an identical twin brother who also became an astronaut, that he helped nurse his wife back from the brink of death after an assassination attempt, and that, after winning a U.S. Senate seat in Arizona that had been held by Republicans for more than half a century, he became a prime target during Pres. Donald Trump’s second term, and you begin to understand the ways in which his biography is, in fact, stranger than fiction.

Early life

Mark Edward Kelly was born on February 21, 1964, roughly six minutes before his twin brother, Scott, entered the world. His parents, Richard and Patricia Kelly, both worked for the West Orange Police Department, his father as a police captain and his mother as a patrol officer. As a teenager, Mark Kelly worked at the local Dairy Queen and was a volunteer for the town’s first-aid squad. He and his brother were largely inseparable growing up; adulthood did little to change that.

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Famous Astronauts and Cosmonauts

Mark Kelly received a bachelor’s degree in marine engineering and nautical science from the U.S. Merchant Marine Academy at Kings Point, New York, in 1986. Scott and Mark became pilots in the U.S. Navy in 1987 and 1989, respectively. Mark flew 39 combat missions during the Persian Gulf War in 1991. Both brothers graduated from the U.S. Navy Test Pilot School in Patuxent River, Maryland, in 1994. That year Mark also received a master’s degree in aeronautical engineering from the U.S. Naval Postgraduate School in Monterey, California.

Life in space

Mark and Scott Kelly began their astronaut training in August 1996. Mark Kelly’s first spaceflight was as pilot of the space shuttle Endeavour on the STS-108 mission (December 5–17, 2001), which carried three astronauts and supplies to the International Space Station (ISS). He flew again to the ISS in July 2006 on the 13-day STS-121 mission as pilot of the space shuttle Discovery. He also made two flights to the ISS as mission commander.

Scott Kelly was launched to the ISS on a Russian Soyuz spacecraft on October 8, 2010, and was on board until March 16, 2011. Mark Kelly was originally scheduled to arrive at the ISS in February 2011 as commander of the space shuttle Endeavour’s last mission; it would have meant that the Kelly twins would have become the first siblings in space at the same time. However, delays in earlier launches derailed those plans. NASA was still able to take advantage of the unique circumstance of having identical twin astronauts by conducting a landmark study on the impact of space on the body, doing side-by-side comparisons of Scott’s bodily functions while he was in space to Mark’s while he was on Earth.

Marriage and tragedy

In November 2007 Kelly married first-term Arizona Democratic Rep. Gabrielle Giffords. Their story was Hollywood perfect: the heroic astronaut and the rising political star. But on January 8, 2011, Giffords was grievously wounded in an assassination attempt in a supermarket parking lot that left six dead and 12 others wounded.

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By May 2011 Giffords had recovered sufficiently to watch Kelly as he returned to space one last time, commanding Endeavour on its final mission. Upon his return, he retired from NASA and the U.S. Navy, to help Giffords with her long recovery. The couple has become outspoken activists for gun control, but Giffords resigned from her seat in Congress in January 2012 as she continued rehabilitation.

Mark Kelly as politician

In 2019 Kelly announced that he was running in a special election for the U.S. Senate from Arizona. The seat he was seeking had been held by Republicans since 1968; its incumbents include such legendary figures as Barry Goldwater and John McCain. But Kelly’s astronaut background and straightforward style, coupled with Arizona’s changing demographics, led him to a two-point victory in 2020. Because it was a special election, he faced voters again in 2022, winning a full six-year term by a five-point margin.

By 2024 Kelly’s profile had risen sufficiently that he was on the short list of potential running mates for the Democratic presidential nominee, Vice Pres. Kamala Harris. Others on the list included Pennsylvania Gov. Josh Shapiro and her ultimate choice, Minnesota Gov. Tim Walz.

In 2025 Kelly appeared in a video with other Democratic legislators who had served in the military or national security roles, including Sen. Elissa Slotkin of Michigan and Reps. Jason Crow of Colorado, Maggie Goodlander of New Hampshire, and Chris Deluzio and Chrissy Houlahan, both of Pennsylvania. In the video the lawmakers remind members of the armed services that they do not need to follow unlawful orders. “You can refuse illegal orders,” Kelly says, adding, “Don’t give up.”

The video incurred the wrath of Trump and Secretary of Defense Pete Hegseth; they both called it “seditious.” Kelly was unique among those who appeared in the video, in that his retired status means that he receives a Navy pension. In January 2026, some six weeks after the video was released and days after Kelly criticized the military mission in Venezuela that swept authoritarian Pres. Nicolás Maduro from power, Hegseth ordered a review of Kelly’s “reckless misconduct,” saying that they could result in a “reduction in his retired grade,” which would cut Kelly’s pension.

Kelly made clear that he would not accept such a demotion without a fight, and he subsequently filed suit against Hegseth. In a statement he said:

Over twenty-five years in the U.S. Navy, thirty-nine combat missions, and four missions to space, I risked my life for this country and to defend our Constitution—including the First Amendment rights of every American to speak out. I never expected that the President of the United States and the Secretary of Defense would attack me for doing exactly that. My rank and retirement are things that I earned through my service and sacrifice for this country.

In February 2026, a grand jury in Washington, D.C., refused to indict Kelly and the other lawmakers who made the video on charges brought by the Trump Justice Department that they violated a statute that prohibits interfering with the loyalty, morale or discipline of the military. It is highly unusual for a grand jury to reject an indictment bid presented by federal prosecutors.