Firefly algorithm error shortened Lockheed satellite mission

A Firefly software algorithm error caused a Lockheed Martin satellite to malfunction, resulting in a much shorter mission than expected following a botched Alpha launch.

According to Firefly Aerospace’s mission update, the investigation determined the mishap was due to an issue in the Guidance, Navigation, and Control (GNC) software algorithm that prevented the system from sending the necessary pulse commands to the Reaction Control System (RCS) thrusters before the relight of the second stage.

This resulted in the 300-pound payload, an Electronic Steerable Antenna (ESA) demonstrator, going into the wrong orbit following an upper-stage problem with the Firefly, dubbed “Fly the Lightning,” on December 22.

Today, Firefly’s Alpha launch had a successful liftoff & progressed seamlessly through each stage of flight, including MECO, stage separation, fairing separation and the first SECO. Alpha’s scheduled stage 2 engine relight did not deliver the payload to its precise target orbit.…

— Firefly Aerospace (@Firefly_Space) December 23, 2023

While the burn of the second stage to circularize the orbit did not go to plan, Lockheed Martin Space technology acceleration director Bob Behnken told SpaceNews, that the company’s antenna technology demonstration payload “exceeded our expectations and successfully completed all primary mission objectives. 

“This feat is even more impressive in light of the spacecraft being placed in an unplanned, lower orbit, which resulted in a dramatically compressed mission timeline,” he added. Ultimately, the payload was explicitly designed to demonstrate quicker on-orbit sensor calibration.

The mission stated that Firefly would now be implementing corrections actions to ensure the GNC software issue is resolved, including process changes to detect and prevent similar issues in the future. “Alpha will be ready to fly again in the coming months,” it added.

“We’re proud of the combined team’s ability to work together to achieve this positive outcome,” said Bill Weber, CEO of Firefly Aerospace. “Looking ahead, the important long-term outcome is the rapid, thorough maturation of Alpha as the dependable one metric ton class rocket the market is demanding, which Firefly is dedicated to and is delivering.”

Firefly satellite missions

“Fly the Lightning” marked Firefly and Alpha’s fourth orbital mission. Their first flight in September 2021 ended in failure shortly after launch, serving as a test mission. Alpha experienced partial success in October 2022, successfully delivering seven satellites to orbit but reportedly deploying them at lower-than-intended altitudes.

The third launch took place in September 2023 as part of the U.S. Space Force’s mission named Victus Nox. This mission was hailed as a resounding success. Alpha achieved a new milestone by launching just 27 hours after receiving the Space Force’s order, setting a new record for national security missions. The primary satellite was deployed into the target orbit as planned.

Featured image: Canva / Firefly Aerospace

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