NASA has reassigned its Sun Radio Interferometer Space Experiment (SunRISE) mission from United Launch Alliance's Vulcan Centaur rocket to SpaceX's Falcon Heavy, the agency confirmed in a mission update.

What Happened

The six-satellite SunRISE constellation was originally scheduled to launch aboard a ULA Vulcan Centaur but has now been assigned to a Falcon Heavy. The spacecraft will fly as part of a rideshare mission sponsored by the U.S. Space Force's Space Systems Command. The switch comes after Vulcan experienced an anomaly in one of its solid rocket boosters during ascent on the USSF-87 mission—the second such incident across the rocket's four flights to date. While USSF-87 delivered its payload to orbit, the recurrence prompted the Space Force to pause national security launches on Vulcan pending resolution. SunRISE is a heliophysics study under NASA's Explorers Program managed by Goddard Space Flight Center. The six smallsats, each roughly the size of a mailbox, will operate from an altitude of approximately 22,000 miles above Earth and fly in a 10-mile-wide X formation, extending roughly 10-foot antenna booms to function as a single radio telescope observing solar radio bursts.

Why It Matters

Solar radio bursts precede the arrival of energetic particles from solar storms, making them key indicators for space weather forecasting. Powerful storms can disrupt satellite electronics and communications, and in severe cases pose radiation risks to astronauts and high-latitude air travelers where Earth's magnetic field is weaker. SunRISE will not operate as an alert system itself; instead, its data will be used to refine prediction models that could help protect orbital infrastructure and crewed missions from space weather events. The mission swap also reflects broader shifts in how the Space Force manages rideshare manifests when launch vehicles face technical stand-downs, with other national security payloads already being shifted between Vulcan and Falcon 9.

The Bottom Line

SunRISE is scheduled to launch later this year aboard a Falcon Heavy; a specific date has not been announced. Falcon Heavy has flown 12 times since its debut in 2018, including four national security missions, with its most recent flight being the Viasat-3 F3 telecom satellite in April.