Firefly Aerospace traces rocket launch failure to premature engine shutdown

Firefly Aerospace's Alpha rocket launches from Vandenberg Space Force Base, California on September 2, 2021. About 2 minutes and 30 seconds into its flight, the rocket crashed.
Representatives of Firefly Aerospace have confirmed that the engine shut down prematurely caused last week's launch failure.

Firefly, a Texas-based company, flew its first ever orbital test flight on Thursday (Sept. 2). The rocket, which is 95 feet tall (29 meters) and was launched from Vandenberg Space Force Base in California. The two-stage launcher started to fall about 2.5 minutes after liftoff and then it exploded in an explosive fireball shortly afterwards.

Firefly immediately initiated an anomaly investigation and has already made significant progress. The company revealed the cause of the failure on Sunday, Sept. 5, when it announced that one of Alpha's first-stage Reaver engines suddenly shut down about 15 seconds after liftoff.

Video: Watch Firefly Aerospace light birthday candles using a rocket engine

The vehicle continued to climb and maintained control for about 145 seconds. However, the nominal first-stage burn time is approximately 165 seconds. The vehicle's climb rate was slow due to the lack of thrust from 1 of the 4 engines. Alpha representatives posted a tweet on Sunday.

Alpha was able compensate at subsonic speeds but, as it moved through supersonic flight and transonic, where control is most difficult, the three engine thrust vector control proved insufficient. The vehicle lost control. The explosive Flight Termination System was used to end the flight. They added that the rocket didn't explode by itself.

Firefly stated that Engine 2 was shut down due to its main propellant valves closing. Firefly continues to investigate the cause of Thursday's flight and to find out if there was anything unusual.

"We will report the root cause of this anomaly at the conclusion of the investigation. Firefly stated in a Twitter thread that she was working with Space Launch Delta 30 and the FAA to return to Alpha Flight 2 as soon possible. Firefly is referring to the U.S. Federal Aviation Administration (FAA) and Vandenberg-based Space Force, which oversees launches from West Coast.

Firefly Aerospace's Alpha rocket is damaged in its first launch. The anomaly occurred 2 minutes and 30 seconds after it lifted off from Vandenberg Space Force Base (California), on September 2, 2021. (Image credit to Everyday Astronaut/Firefly Aerospace).

Firefly's specifications page states that Alpha is an expendable rocket capable of delivering up to 2,200 pounds (1,099 kg) to low earth orbit for each $15 million mission. The rocket launched on Thursday with a payload of 203 pounds (92 kilograms) called DREAM ("Dedicated Research and Education Accelerator Mission") which included memorabilia donated by schools and other institutions as well as a few small satellites.

SpaceNews reports that Alpha also carried parts of Firefly's space tug, the Space Utility Vehicle. This gave them an in-space test.