Space Exploration Technologies Corp. (SpaceX) scrubbed the inaugural launch of its Falcon 1 rocket Nov. 25 and does not expect to perform the mission until December, the company announced.

The delay was caused by an auxiliary liquid oxygen fill tank that had a manual vent valve incorrectly set to vent, SpaceX CEO Elon Musk said in a statement. “The time it took to correct the problem resulted in significant liquid oxygen boiloff and loss of helium, and it was the latter that caused the launch abort,” he said.

SpaceX expects to reschedule the launch within a week at the earliest, but Musk said it will probably be longer “as we need to bring in liquid oxygen and helium from Hawaii.”

The mission, which will take place from Kwajalein Atoll in the Marshall Islands, will carry Falconsat-2 into orbit. The spacecraft, part of the U.S. Air Force Academy’s satellite program, will measure space plasma phenomena, which can adversely affect space-based communications, including GPS and other civil and military communications.