Gusty winds associated with a subtropical low pressure system prevented United Launch Alliance from sending an Atlas 5 rocket into orbit Saturday from Cape Canaveral with the U.S. Air Force’s clandestine X-37B spaceplane. ULA plans to try again Sunday, delaying a SpaceX Falcon 9 rocket launch from a nearby pad to Monday.
ULA had reserved Sunday as a backup launch date for the Atlas 5 rocket weeks ago, before SpaceX requested the same day on the U.S. Space Force’s Eastern Range after delaying its launch from earlier in May. The range provides safety and other support functions for rocket launches from Cape Canaveral and the Kennedy Space Center.
The range typically operates on a first-come, first-served basis, so SpaceX’s Falcon 9 mission could only launch Sunday if the Atlas 5 rocket lifted off from Cape Canaveral’s Complex 41 launch pad Saturday.
The Atlas 5 and Falcon 9 rockets are standing about a mile-and-a-half apart on neighboring launch pads at Cape Canaveral Air Force Station.
After high winds and cumulus clouds prevented launch of the 197-foot-tall (60-meter) Atlas 5 rocket at 8:24 a.m. EDT (1224 GMT), ULA targeted Saturday’s back-up 10-minute launch window. The launch team proceeded with the terminal countdown for a potential liftoff of the Atlas 5 at 10:23 a.m. EDT (1423 GMT) in hopes weather conditions might improve.
In the end, the weather remained unfavorable and ground winds tripped the Atlas 5’s launch limit.
“The ground winds exceeded the limit of what we could safely fly through,” said Julie Arnold, a ULA spokesperson.
Officials called off the countdown at T-minus 1 minute, 40 seconds.