A Northrop Grumman Minotaur IV rocket launched the NROL-174 mission from Vandenberg Space Force Base in California on April 16, 2025. It was the first launch of a Minotaur IV from the site since 2011, the National Reconnaissance Office confirmed.

From Nuclear Deterrent to Space Launch

The Minotaur IV rocket was once a Peacekeeper intercontinental ballistic missile that stood watch 24/7 as part of America’s nuclear deterrent. After being decommissioned under arms reduction treaties, the missile was converted into a space launch vehicle.

The rocket uses three government-furnished solid rocket motors from decommissioned Peacekeeper ICBMs for its first three stages, with a commercial solid rocket upper stage built by Northrop Grumman. The four-stage vehicle stands 78 feet tall and can carry payloads up to 1,730 kg to low Earth orbit.

The Mission

The NROL-174 mission launched at 3:33 p.m. EDT from Space Launch Complex 8 at Vandenberg Space Force Base. The launch carried multiple classified national security payloads for the National Reconnaissance Office, which builds and operates US spy satellites.

“Now modified for space launch, it completed its final mission of placing a national security payload on orbit,” said Laura Robinson, Deputy Director of the NRO Office of Space Launch. The successful launch marked a tribute to decades of work converting the missile into a space vehicle.

Part of a Flexible Launch Program

NROL-174 is the third mission launched under the Orbital/Suborbital Program-3 contract, which is managed by the US Space Force’s Rocket Systems Launch Program. The program provides the government with flexible access to space by purchasing rides on smaller rockets like the Minotaur IV.

Previous Minotaur launches under this program include NROL-129 in July 2020 and NROL-111 in June 2021, both from Wallops Flight Facility in Virginia.

Proven Reliability

“Since the first launch in January of 2000, our Minotaur rockets have continued to provide unique and reliable space launch solutions to support national security missions for the US government,” said Mike Pinkston, vice president of launch vehicles at Northrop Grumman.

The Minotaur family of rockets has completed missions from every major US spaceport, demonstrating versatility and reliability for government-sponsored payloads. The vehicles combine government-supplied rocket motors with proven commercial launch technologies.