Former astronaut Alan “Dex” Poindexter, 50, a space shuttle commander who flew twice into space, died July 1 after being injured in a water sports accident in Florida, NASA has confirmed.

“The NASA family was sad to learn of the passing of our former friend, and colleague Alan Poindexter who was killed today during a jet ski accident in Florida,” the agency wrote on Facebook. “Our thought and hearts are with his family.”

Poindexter was with his two sons near Little Sabine Bay off Pensacola Beach, Fla., when the accident occurred, according to local media reports.

“Poindexter and his 21-year-old son were on one jet ski and his oldest son was on another jet ski. Poindexter was sitting still in the water when his [older] son’s jet ski came barreling into him,” the local ABC affiliate WEAR reported, citing the Florida Fish and Wildlife Commission, which investigates boating accidents.

Poindexter was rushed to Baptist Hospital in Pensacola, where he later died from his injuries.

Named as an astronaut in 1998, Alan Poindexter was a veteran of two spaceflights. In February 2008, he flew as pilot on the Space Shuttle Atlantis’ STS-122 mission to deliver and install the European Space Agency’s Columbus laboratory for the international space station.

Two years later in April 2010, Poindexter commanded the Space Shuttle Discovery on its second-to-last spaceflight. The STS-131 mission delivered more than 5,900 kilograms of hardware and equipment to the space station.

In total, Poindexter logged 27 days and 21 hours in space over the course of his two missions.

A U.S. Navy captain with more than 4,000 hours in more than 30 different aircraft types, including more than 450 aircraft carrier landings, Poindexter left NASA in 2010 to return to his alma mater, the Naval Postgraduate School in Monterey, Calif. Poindexter was still serving there as dean of students and executive director of programs at the time of his death.

Poindexter is survived by his wife, Lisa, and their two grown sons.