Leading launch and space systems company Rocket Lab today announced it has
concluded an extensive review into the cause of the anomaly that resulted in
the loss of its “Running Out Of Toes” mission launched on May 15, 2021. With
the root cause of the issue identified and corrective measures now in place,
Electron will be back on the pad for the next mission from Launch Complex 1
later this month.
The May 15 anomaly occurred after 17 successful orbital flights of the
Electron launch vehicle which has deployed more than 100 satellites to orbit
since 2018. Immediately following the anomaly, Rocket Lab launched a
rigorous internal review, assembling its investigation team with oversight
by the Federal Aviation Administration (FAA). The investigation team scoured
thousands of channels of telemetry and systems data from the flight and
worked systematically through an extensive fault tree analysis to determine
the cause of the failure.
The review concluded that an issue occurred within the second stage engine
igniter system almost three minutes and 20 seconds into the flight. This
induced a corruption of signals within the engine computer that caused the
Rutherford engine’s thrust vector control (TVC) to deviate outside nominal
parameters and resulted in the engine computer commanding zero pump speed,
shutting down the engine.
The igniter fault resulted from a previously undetectable failure mode
within the ignition system that occurs under a unique set of environmental
pressures and conditions. The issue was not evident during extensive
pre-flight testing for this mission, including more than 400 seconds of burn
for this particular engine, more than 1,500 Rutherford engine hot fires to
date, and 17 successful orbital launches. Rocket Lab has since been able to
reliably replicate the issue in testing and has implemented redundancies in
the ignition system to prevent any future reoccurrence, including
modifications to the igniter’s design and manufacture.
The anomaly review confirmed that Electron’s first stage performed
flawlessly during the mission and did not contribute to the flight issue. As
a result, Rocket Lab was able to conduct a successful reentry, ocean
splashdown and recovery of the first stage as planned, marking a major
milestone in the company’s program to make Electron a reusable launch
vehicle.
Satisfied with its own review of the May 15 launch, the FAA confirmed in
June that Rocket Lab’s launch license remains active. With corrective
measures now in place, Rocket Lab is returning to the pad with an even more
reliable launch vehicle to meet a busy launch schedule in the second half of
2021. Details of the next Electron mission will be made available in the
coming days.