NASA has performed a rocket switcheroo for its SunRISE solar observatory. Instead of flying on the United Launch Alliance Vulcan Centaur it was originally booked to use, SunRISE will now launch on a SpaceX Falcon Heavy, using a rideshare sponsored by the United States Space Force's Space Systems Command.

The timing pressure here is real, because the Vulcan Centaur problem is not theoretical. In February, the fourth Vulcan Centaur flight experienced a booster anomaly during a US Space Force launch. The payload made it to orbit, but burn-through of a Solid Rocket Booster (SRB) nozzle made the trip more eventful than planned. Space Force reportedly paused all national security launches on the Vulcan Centaur until the investigation was complete and appropriate corrective action was taken. SunRISE, originally due to launch on Vulcan in summer 2026 after completing its final prelaunch testing at the beginning of 2026, got caught in the fallout.

For decision-makers, the core issue is schedule risk under national security launch constraints. Vulcan Centaur had a role to play for the Space Force, and once a booster anomaly hits, the customer tends to get conservative fast.