Vulcan Centaur swapped out again: NASA goes with SpaceX Falcon Heavy rocket for launch of space weather mission

NASA is shaking things up for its next mission to research the sun.

The six satellites of NASA's Sun Radio Interferometer Space Experiment (SunRISE) mission are poised to launch to Earth orbit soon, to serve as an early warning system for incoming solar storms. They were originally slated to lift off on a United Launch Alliance (ULA) Vulcan Centaur rocket but have now been assigned a SpaceX Falcon Heavy, according to a NASA mission update.

SunRISE will fly to space as part of a rideshare mission sponsored by the U.S. Space Force's (USSF's) Space Systems Command (SSC). Though it's not stated specifically in the NASA release, that may be a hint as to why the mission's rocket was changed. On its most recent launch, USSF-87, Vulcan experienced an anomaly in one of its solid rocket boosters — the second such incident to occur during the rocket's four launches to date.

Vulcan succeeded in delivering the USSF-87 payload to its designated orbit on that launch, but the recurrence of the booster issue during ascent prompted the Space Force to pause national security launches on Vulcan until it could be addressed. Which mission SunRISE will be manifested on has not yet been released, but SSC has already shifted other launches between Vulcan and SpaceX's Falcon 9, so NASA's change in rockets for SunRISE could indicate either that the mission has been remanifested on a different SSC rideshare, or that another SSC mission has been shifted from Vulcan entirely.

SunRISE is a heliophysics study under the NASA Science Mission Directorate's "missions of opportunity" umbrella and is part of the Explorers Program run by Goddard Space Flight Center in Greenbelt, Maryland. It consists of six small satellites, each about the size of a mailbox. The mini-constellation's mission is led by scientists at the University of Michigan and will be managed out of NASA's Jet Propulsion Laboratory in Southern California.

The half-dozen smallsats will be delivered to an orbit about 22,000 miles (3…