Sen. Mark Kelly (D-Ariz.) marked the 20th anniversary of his STS-121 mission aboard Space Shuttle Discovery, reflecting on the rare July 4, 2006, launch and calling it a proud example of U.S. space exploration and innovation.

NASA’s Rare July 4 Shuttle Launch

On Saturday, in a post on X, Kelly recalled launching on July 4, 2006, as part of the STS-121 mission.

"20 years ago today, I launched aboard Discovery on STS-121, the only shuttle mission ever to launch on July 4th," Kelly wrote.

He added, "Pretty good way to spend Independence Day. Proud of everyone who made that mission happen and still proud of what this country can do when we invest in exploration."

STS-121 was a critical NASA mission focused on testing shuttle safety improvements and resupplying the International Space Station following the Columbia disaster.

NASA Artemis Missions

Last month, NASA named the four astronauts for the 2027 Artemis III mission, which will test Orion’s docking capabilities with commercial lunar landers from SpaceX and Blue Origin to support future Moon missions.

Earlier this year, Artemis II completed a successful nearly 10-day lunar flyby and returned safely to Earth, with NASA celebrating the milestone by posting, "Welcome home."

Blue Origin Moon Lander

Earlier, Jeff Bezos-owned Blue Origin’s Blue Moon Mark 1 lunar lander passed key environmental tests at NASA’s Johnson Space Center, confirming it can withstand harsh space-like conditions ahead of its upcoming uncrewed Moon mission.

The results mark an important step toward supporting future Artemis-era lunar exploration.

Separately, President Donald Trump joked during a meeting with the Artemis II mission astronauts that he would have "no trouble" becoming an astronaut and asked about the possibility of a president flying in space.

NASA Administrator Jared Isaacson said more launches could create future opportunities, while Trump emphasized U.S. leadership in returning humans to the Moon after more than 50 years.