The launch is difficult, but with each missile sending highly detailed live telemetry to headquarters, teams can know within days or weeks what led to a failed launch. Case in point: Virgin Orbit’s much-hyped first launch from British soil last month, which failed to reach orbit – apparently due to a single loose fuel filter.
In an update posted to the website today, Virgin Orbit explained first, that everything went perfectly at every step leading up to the problem, including ignition, flight of the first stage, separation of the stages, ignition of the second stage, and fair deployment – all of which are times when mission-ending failures can occur.
But that’s when things nominally depart:
The data indicates that from the start of the second stage’s first combustion, a fuel filter in the fuel supply line had become dislodged from its normal position.
Additional data shows that the fuel pump located downstream of the filter was operating at a reduced efficiency level, causing the Newton 4 engine to run out of fuel. By performing in this anomalous manner, the motor was operating at a significantly higher than rated motor temperature.
Components downstream and near the abnormally hot engine eventually malfunctioned, causing the second stage’s thrust to stop prematurely.
For lack of a filter, the mission was lost. It’s a sobering reminder that launch vehicles, if they succeed, are collections of thousands of moving parts that operate with perfect precision — or at least within tolerances.
A fuel filter that is not properly secured, or has a minor manufacturing defect that causes it to come loose, is the butterfly flapping its wings and causing the hurricane downstream. It all happens in a handful of seconds, but the data returned will be clear enough to engineers when they have time to look at it later.
So what’s the solution? At least a new fuel filter, says Virgin Orbit CEO Dan Hart:
“Our investigation is not yet complete…However, now that many clear clues from extensive data analysis have been understood, we are modifying our next missile with a more robust filter and looking broadly to ensure that all credible contributors to mission failures are eradicated and addressed.”
Thus, they will “proceed with caution” towards their next launch, from the US; a commercial cargo that they expect to announce details in a few weeks.