Written by 
LOS ANGELES, CA — Southern California residents may hear a loud boom Saturday night, and it won’t be the Disneyland fireworks, a quake or a crash to blame. It will be a sonic boom created by a late night rocket launch from Vandenberg Space Force Base near Lompoc.
A SpaceX launch is scheduled at the Santa Barbara County base at 10:13 p.m., and it could produce a sonic boom heard across Southern California. It may also put on a light show that can be seen for hundreds of miles.
SpaceX will use its Falcon 9 rocket to launch a series of satellites into low Earth-orbit for the internet provider OneWeb.
The reusable rocket, which frequently lands on a barge in the ocean, will attempt to land back at the base. About eight minutes after liftoff, the rocket’s first stage is expected to come back to earth at Vandenberg slowing to the spead of sound in the process — that’s when people may hear one or more sonic booms, SpaceX said.
“Sonic booms are caused by an object moving faster than sound — about 750 miles per hour at sea level. An aircraft traveling through the atmosphere continuously produces air-pressure waves similar to the water waves caused by a ship’s bow,” according to the Edwards Airforce Base website. “When the aircraft exceeds the speed of sound, these pressure waves combine and form shock waves which travel in all directions and eventually reach the ground. The sound heard on the ground is the sudden onset and release of pressure after the buildup by the shock wave.”
In the past, similar events have rattled windows all across Southern California, while other times, the boom is limited to Santa Barbara and Ventura counties.
“This is the seventh flight of the first stage booster supporting this mission, which previously launched USSF-62 and five Starlink missions. Following stage separation, the first stage will land on Landing Zone 4 (LZ-4) at Vandenberg Space Force Base.,” the company announced.
If the launch is scrapped at the last minute, a backup launch is slated for Sunday at 10:08 p.m.
The mission will b streamed live starting just before liftoff on X @SpaceX. You can also watch the webcast on the new X TV app.