Arizona Sen. Mark Kelly knows a few things about objects in outer space, including those that make their way to Earth.

The next presidential election is still a few years away, but Arizona's senators could be contenders in a wide-open ...

Senators introduce a resolution to designate June 30 as National Asteroid Day, emphasizing planetary defense and public ...

The next presidential election is still a few years away, but Arizona's senators could be contenders in a wide-open ...

As the nation reels from the latest outbreak of political violence, the senator from Arizona and his wife, former Rep. Gabby Giffords, recalled the horrific attack that tore apart their lives as they ...

Kelly and Giffords, who was badly wounded in a 2011 attack in her congressional district, appealed for action to address violence that the former Navy pilot and astronaut said makes the U.S. stand ...

Astronaut and Navy captain Mark Kelly has announced his retirements. In a letter posted on his Facebook page, Kelly says. "Words cannot convey my deep gratitude for the opportunities I ...

President Donald Trump wants a national missile defense system like Israel's, but Sen. Mark Kelly, D-Ariz., raised doubts that it is viable.

Sen. Mark Kelly of Arizona questioned the feasibility of President Donald Trump's proposed "Golden Dome" missile defense system, citing concerns about its physics and cost.