Officials have issued a warning that residents in California’s Santa Barbara, San Luis Obispo, and Ventura counties may hear one or more sonic booms roughly eight minutes after SpaceX’s Falcon 9 launch on Tuesday, July 22, 2025. The loud, thunder-like sounds are expected as the rocket’s first stage makes its high-speed return to Earth and attempts a landing at SpaceX’s Landing Zone 4 at Vandenberg Space Force Base. While potentially startling, the booms are harmless and a routine feature of SpaceX’s reusable rocket system. The launch, scheduled for 11:13 a.m. PDT, will carry NASA’s TRACERS mission and three additional payloads into orbit during a 57-minute launch window.

SpaceX to launch NASA’s TRACERS mission aboard Falcon 9 from Vandenberg

The upcoming mission will launch from Space Launch Complex 4 East at Vandenberg Space Force Base. Falcon 9 will carry NASA’s TRACERS satellites (Tandem Reconnection and Cusp Electrodynamics Reconnaissance Satellites), designed to study the interaction between solar wind and Earth’s magnetosphere. This data is expected to improve scientific understanding of space weather and its effects on satellite communications and Earth’s atmosphere. Alongside TRACERS, three smaller research satellites will also hitch a ride into orbit.

Why Falcon 9’s return causes sonic booms

Sonic booms occur when a vehicle travels faster than the speed of sound, creating shock waves that reach the ground as loud, abrupt noises. In SpaceX launches, the Falcon 9 booster separates from the upper stage shortly after liftoff and performs a controlled descent back to Earth. As it slows down and lands vertically at Landing Zone 4, it breaks the sound barrier, resulting in one or more sonic booms. These booms may vary in intensity depending on weather conditions and flight trajectory.

Residents advised not to panic

Officials have emphasized that these sounds are expected and are no cause for concern. The booms are not harmful and are a byproduct of SpaceX’s innovative reusable rocket technology, which has become a standard part of its missions. Past launches have triggered similar public alerts to avoid alarm when sonic booms occur.

How to follow the launch of TRACERS mission

NASA and SpaceX will provide live coverage of the launch event on their respective websites and social media platforms. Local authorities may also issue real-time updates or reminders to residents in affected areas. In the event of a delay, a backup launch window is available on Wednesday, July 23, at the same time.As Southern California braces for a brief rumble from above, the mission marks yet another step forward in understanding the space environment that surrounds our planet.