SpaceX Moves USSF-627 Launch to Wednesday Backup Window at Vandenberg

SpaceX did not launch the USSF-627 mission from Vandenberg Space Force Base on Tuesday evening, and the Falcon 9 attempt now works to the backup opportunity the company published for the flight. The four-hour backup window opens at 6:35 p.m. PT on Wednesday at Space Launch Complex 4E and runs to 10:35 p.m. PT, according to the updated launch listings for the mission.

The target has moved twice this week. The mission was first set for Monday evening, then for a Tuesday window opening at 6:49 p.m. PT, and the Wednesday slot was listed as the backup when the Tuesday target was published. No reason for the latest move accompanied the updated listings, and launch targets at Vandenberg change often as the countdown approaches.

U.S. Space Force photo by 2nd Lt. Andrew Taller, via Wikimedia Commons (public domain)

Nothing else about the flight plan has changed in the published material. USSF-627 remains a classified satellite deployment mission for the U.S. Space Force, and SpaceX has published no details about the payload. The first stage booster flies for the seventh time, after earlier flights that included the NROL-179, SDA-T1TL-E and SDA-T1TL-A missions and three Starlink launches, and it is scheduled to land on the Of Course I Still Love You droneship in the Pacific Ocean after stage separation.

A live webcast is scheduled to begin about 10 minutes before liftoff, carried on the company mission page and on its X account. SpaceX lists sonic booms as possible in Santa Barbara, San Luis Obispo and Ventura counties, with whether they are heard on the ground set by the weather and other conditions. Wednesday's attempt follows the USSF-432 mission flown from the same complex at the end of last week, also on a Falcon 9 for the Space Force.

SpaceX, via Spaceflight Now