SpaceX launches advanced GPS satellite for US Space Force after rocket swap (photos)

SpaceX launched a new GPS satellite for the U.S. Space Force early Tuesday morning (April 21) — a mission that was originally supposed to fly on a competitor's rocket.

A SpaceX Falcon 9 rocket launches the GPS III SV10 satellite for the U.S. Space Force from Florida on April 21, 2026. (Image credit: SpaceX)

"GPS III satellites have a three-fold increase in positional accuracy and an eight-fold improvement in jam resistance compared to prior versions," Space Force officials said in a statement on Jan. 28, just after GPS III SV09 rode a Falcon 9 to orbit.

"These advanced features enable the constellation to provide an across-the-board boost in effectiveness and lethality to weapon systems in every theater," they added.

GPS III SV10 was originally supposed to fly aboard United Launch Alliance's new Vulcan Centaur rocket. Last month, however, the Space Force announced that it was switching the satellite to a Falcon 9 due to issues that Vulcan has experienced with its solid rocket boosters (SRBs).

As part of this rocket swap, Vulcan Centaur will now launch the USSF-70 national security mission, which had been slated to fly on a SpaceX Falcon Heavy. USSF-70 is expected to launch no earlier than summer 2028, Space Force officials have said. (Presumably, Vulcan Centaur's SRB issues will be worked out by then.)

closeup photo of the base of a white and black rocket on the deck of a ship at sea at night — The Falcon 9's first stage rests on the deck of a ship at sea shortly after launching the GPS III SV10 satellite on April 21, 2026. (Image credit: SpaceX)

The Falcon 9's first stage came back to Earth about 8.5 minutes after launch as planned on Tuesday, touching down softly in the Atlantic Ocean on the SpaceX droneship "Just Read the Instructions."

It was the seventh launch and landing for this particular booster, according to a SpaceX mission description. And it was the final Falcon landing for "Just Read the Instructions," SpaceX said during Tuesday's launch commentary; the droneship will now pivot to supporting liftoffs of SpaceX's Starship megarocket.

The Falcon 9's upper stage, meanwhile, continued powering its way to medium-Earth orbit. It will deploy GPS III SV10 there about 90 minutes after liftoff.

Editor's note: This story was updated at 1:15 a.m. ET on April 20 with the new target launch date of April 21. It was updated again at 3:04 a.m. ET on April 21 with news of successful launch and rocket landing.

Michael Wall is the Spaceflight and Tech Editor for Space.com and joined the team in 2010. He primarily covers human and robotic spaceflight, military space, and exoplanets, but has been known to dabble in the space art beat. His book about the search for alien life, "Out There," was published on Nov. 13, 2018. Before becoming a science writer, Michael worked as a herpetologist and wildlife biologist. He has a Ph.D. in evolutionary biology from the University of Sydney, Australia, a bachelor's degree from the University of Arizona, and a graduate certificate in science writing from the University of California, Santa Cruz. To find out what his latest project is, you can follow Michael on Twitter.