Fuel line issues caused Virgin Orbit’s LauncherOne rocket to overheat, causing its first mission failure last month, a preliminary investigation shows.

The Long Beach-based small satellite launch company’s modified Boeing 747 took off from Spaceport Cornwall in the United Kingdom on Jan. 9, marking the first orbital launch from UK soil in addition to being Virgin Orbit’s first international mission.

The rocket successfully reached space but experienced an “anomaly” shortly after the ignition of its second stage, causing a premature thrust shutdown, ending the mission.

An investigation into the anomaly began within hours of the failure. The team, led by aerospace veteran Jim Sponnick and Virgin Orbit Chief Engineer Chad Foster, has determined that a fuel filter became dislodged from its normal position within the feedline and that a fuel pump downstream was not operating at full capacity, causing the Newton 4 engine to run extremely hot, the company announced this week.

The high temperature of the engine caused other components to malfunction and, ultimately, led to the rocket shutting down. The rocket and its payload of eight satellites fell back to Earth, landing in the Atlantic Ocean.

“In space launch, a failure is painful for all involved,” Virgin Orbit CEO Dan Hart said in a statement. “Intense disappointment gets quickly channeled into the motivation to dig into the cause, to understand all contributing elements and to thereby get back to flight with a better system and a wiser team.”

The company is already modifying its next rocket with a “more robust filter,” according to Hart.

The investigation is ongoing and includes oversight by the U.S. Federal Aviation Administration and the UK Air Accidents Investigation Branch with participation by the Department of Defense, the National Reconnaissance Office and the UK Civil Aviation Authority.

The mission, dubbed “Start Me Up” after the 1981 Rolling Stones song, had a target of delivering its payload to a 555-kilometer sun-synchronous orbit, including:

  • IOD-3 AMBER: The first of more than 20 such satellites developed by Satellite Applications Catapult and Horizon Technologies, and built by AAC Clyde Space, that will provide space-based maritime data.
  • Prometheus-2: Two CubeSats—owned by the U.K. Ministry of Defense (MOD) and co-funded with Airbus Defence and Space, which are also designing them jointly with In-Space Missions—will support the MOD’s science and technology activities in orbit and on the ground.
  • CIRCE (Coordinated Ionospheric Reconstruction CubeSat Experiment): A joint mission between the U.K.’s Defense Science and Technology Laboratory and the U.S. Naval Research Laboratory.
  • DOVER: A pathfinder for global navigation satellite systems developed by RHEA Group, co-funded through the European Space Agency’s Navigation Program and built by Open Cosmos.
  • ForgeStar-0: A returnable and reusable platform to enable in-space manufacturing developed by Space Forge of Wales.
  • AMAN: An earth observation satellite meant to demonstrate the future feasibility of a larger constellation of satellites, which was developed after a memorandum of understanding among the Sultanate of Oman, Polish small satellite manufacturer and operator SatRev, Poland-originated AI data analytics specialists TUATARA and Omani-based merging technology innovator ETCO.
  • STORK-6: The next installment of SatRev’s STORK constellation, for which Virgin Orbit has previously launched two spacecraft.

The failure comes after the company successfully delivered 33 satellites over four missions.

The company’s next mission is slated to launch from the Mojave Air and Space Port in June, according to rocketlaunch.live. The company is expected to make an announcement about its next launch in the coming weeks.

“With those modifications being incorporated on our factory floor,” Hart said, “we will proceed cautiously toward the launch of our next rocket, which is well into the integration and test process.”