Update for 10:55 a.m. ET on Dec. 20: Firefly has scrubbed today's (Dec. 20) planned Alpha rocket launch due to weather concerns. The company has not yet announced a new target date.
Firefly Aerospace plans to launch its fourth-ever mission today (Dec. 20), and you can watch the action live.
The company's Alpha rocket is scheduled to lift off from California's Vandenberg Space Force Base today during a 20-minute window that opens at 12:24 p.m. EST (1724 GMT; 9:24 a.m. local California time), kicking off a mission that Firefly calls "Fly the Lightning." The launch was delayed by six minutes "to support optimal ground tracking for the mission", Firefly officials wrote on X, formerly Twitter.
You can watch the launch live via Firefly and its streaming partner, NASASpaceflight.com. Coverage will begin an hour before the window opens.
Related: New record! Firefly Aerospace launches Space Force mission 27 hours after receiving order
Fly the Lightning will send an electronically steerable antenna (ESA) payload developed by aerospace giant Lockheed Martin to low Earth orbit.
The instrument "will demonstrate faster on-orbit sensor calibration to deliver rapid capabilities to U.S. warfighters," Firefly representatives wrote in a mission description.
"The ESA sensor is expected to calibrate in a fraction of the time it takes to operationalize traditional on-orbit sensors, which historically can take months to be powered on, fully calibrated and ready to perform their mission," they added.
The sensor will be deployed about 54.5 minutes after launch, if all goes according to plan.
Fly the Lightning will be the fourth orbital mission for Firefly and the 95-foot-tall (29 meters) Alpha rocket.
The rocket debuted in September 2021 on a test flight that failed shortly after liftoff. The second try, in October 2022, was a partial success; Alpha delivered seven satellites to orbit but apparently deployed them too low, leading to early reentries.
Flight 3, a mission for the U.S. Space Force called Victus Nox, was a triumph. Alpha lifted off just 27 hours after the Space Force gave the order, a shorter turnaround than on any previous national-security mission. The rocket also deployed its primary payload — a satellite that will perform a "space domain awareness" mission — at the proper altitude.
Though Fly the Lightning's customer is a private company, the U.S. military will be watching the liftoff with keen interest.
"The launch is being observed by members of the U.S. Space Force Tactically Responsive Space team to inform future missions and the requirements for repeatable on-demand launch capabilities," Firefly wrote in the mission description.
If Alpha can't get off the ground today, Firefly has backup opportunities through Friday (Dec. 22).
This story was updated at 9:58 a.m. EST to reflect a six-minute launch delay.
