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 (35,000 kilometers) above Earth — just above a geostationary parking altitude — and fly in a giant 10-mile (16-km) “X” formation, each extending its roughly 10-foot (2.5-meter) antenna booms to act as a single large radio telescope to track solar radio bursts. These kinds of bursts travel faster than the energetic particles from a solar storm, and precede their arrival when shot towards Earth.
Powerful solar storms, like the one that hit Earth in January, are capable of disrupting or disabling satellites by interfering with onboard electronics, sensitive instruments and communications systems. If a storm is severe enough, it can pose a radiation threat to astronauts in orbit and even airborne passengers flying near Earth’s poles, where the planet’s magnetic field is weaker.
SunRISE will help researchers better understand the behavior of incoming solar radio bursts, but the mission won’t serve as an alert system by itself. Instead, scientists will use data collected by the spacecraft to improve prediction models for impending space weather, which in turn could lead to mitigation plans to better thwart the effects of such solar events on orbital infrastructure.
Falcon Heavy is SpaceX‘s heavy-lift launch vehicle, capable of launching up to 58,860 pounds (26,700 kg) to geostationary transfer orbit. It’s a triple-booster rocket that consists of three modified Falcon 9 first stages, and has launched 12 times since it debuted in 2018. Four of those have delivered national security payloads to orbit, with the most recent of those, USSF-52, launching in December 2023. Falcon Heavy’s most recent flight overall occurred this past April, when it sent the Viasat-3 F3 telecom satellite to orbit.
Falcon Heavy’s next mission will lift off with NASA’s Nancy Roman Space Telescope, currently set for no earlier than Aug. 30. SunRISE is scheduled to launch later this year, but a more specific launch window has not yet been announced.