Wildfire Near Vandenberg Air Force Base in California Rages On

PHOTO: This photo released by the U.S. Air Force shows a wildfire burning at a central California Air Force base, Sept. 18, 2016, that forced the postponement of a satellite launch at Vandenberg Air Force Base, California. PlayCol. Michael Wulfestieg/U.S. Air Force via AP
WATCH Western Wildfires Burn Through Air Force Base

A wildfire near Vandenberg Air Force Base in California continues to rage, growing in size to more than 12,000 acres Wednesday, authorities said, noting the fire is 45 percent contained as of early this morning.

The fire boundary was relatively stable as of late Tuesday, as the fire continues to burn along part of the southeast ridgelines, base fire officials said. The blaze is not likely to spread beyond containment lines, Vandenberg officials added in a statement this morning.

"Overnight tonight, a specially equipped aircraft will survey the fire boundary to determine its size and location," base officials said in a statement. "Using infrared heat detection, the aircraft will gather data that is used to build a map of the fire. Fire officials are hopeful the flight tonight will show gains made over the course of the day."

PHOTO: In this photo released by the U.S. Air Force shows a wildfire burning at a central California Air Force base on Sept. 18, 2016. Michael Peterson/U.S. Air Force Photo/Released via AP
In this photo released by the U.S. Air Force shows a wildfire burning at a central California Air Force base on Sept. 18, 2016.

The wind is forecast to blow northwest, according to authorities at the base, and that wind is expected to aid firefighting efforts by directing the fire toward already burned areas.

About 1,000 firefighters have been deployed to fight the fire, and "steady progress" has been made, officials said, though hotspots will likely linger for several days.

PHOTO: In this Monday, Sept. 19, 2016 photo provided by the Santa Barbara County Fire Department, a fire burns several miles behind Space Launch Complex-3, housing the Atlas V rocket & WorldView 4 satellite, at Vandenberg Air Force Base, California. Mike Eliason/Santa Barbara County Fire Department via AP
In this Monday, Sept. 19, 2016 photo provided by the Santa Barbara County Fire Department, a fire burns several miles behind Space Launch Complex-3, housing the Atlas V rocket & WorldView 4 satellite, at Vandenberg Air Force Base, California.

ABC News' Max Golembo contributed to this report.