Rocket Lab’s Electron rocket is once again looking towards the skies, poised to return to flight no earlier than November 28th following a mission failure and loss of payload on September 19th. After stage separation, an anomaly occurred in the second stage resulting in a failure to orbit. This incident marked Electron’s third failure since 2020, once again raising concerns about the reliability of the launch vehicle, specifically the upper stage, which is where each of the three previous mission-ending anomalies have occurred.
The launch, Electron’s 40th, was the second of four dedicated launches for Capella space. The rocket was carrying an Acadia Synthetic Aperture Radar (SAR) Earth-imaging satellite when the anomaly occurred.
Prior to the September 13 failure, Electron had been enjoying a string of successes. The first of the three previous failures occurred during Electron’s 13th flight in July 2020, which was attributed to a single faulty electrical connection that went undetected during preflight testing. The intermittent securement of the wiring led to increasing resistance, causing heating and thermal expansion. This, in turn, ultimately resulted in a disconnect of electricity. The power cut from the electric turbopumps, necessary for the second stage’s single Rutherford engine to function, forced the engine to shut down. Although no modifications to Electron were made following the incident, Rocket Lab affirmed that changes were made to quality control protocols.
Similarly during Electron’s 20th flight, the second stage engine shut down prematurely, causing the mission’s loss. The investigation into this failure revealed that a second stage igniter fault induced interference with the engine controller, leading the vehicle to stray off course and activate the flight termination system.
A formal review of the September 19th anomaly has yet to be published. However, after more than seven weeks analyzing just 1.6 seconds worth of anomaly data, Rocket Lab disclosed during third-quarter financial results update that their findings “overwhelmingly indicate that an electrical arc occurred within the power supply system that provides high voltage to the Rutherford engine’s motor controllers, shorting the battery packs which provide power to the launch vehicle’s second stage”, and that “the root cause of the electric arc is believed to be a unique combination of conditions, including the Paschen Law phenomenon, alternating current (AC) over direct current (DC) high voltage supply, a small concentration of helium and nitrogen, and an imperceptible fault in the insulation of the high voltage loom.”
As the Electron’s return to flight approaches, Rocket Lab assures that improvements have been made to the fidelity of vacuum testing, involving more sensitive instruments. Hardware modifications have also been implemented to prevent this “unique and unusual” phenomenon from occurring in the future.
The upcoming mission, titled “The Moon God Awakens,” will see Electron delivering a SAR imaging satellite into orbit for Japan’s iQPS, an Earth imaging company. The satellite, named TSUKUYOMI-I, is part of a planned constellation of 36 iQPS imaging satellites, which would be a significant victory for Rocket Lab should the company be awarded future launches.
In the wake of these challenges, Rocket Lab continues its slow march towards perfecting the Electron rocket and bolstering confidence in the vehicle’s reliability on its path towards what the company hopes will one day include full reusability.
This recent failure underscores that the path to space is a difficult one, and that despite the number of orbital launches around the globe increasing each year, the art of spaceflight is far from perfected. Electron’s journey, like every other launch vehicle, has been fraught with setbacks and triumphs, and reminds us that the continuous pursuit of perfection in spaceflight is not made by giant leaps, but of many small steps. The lessons learned from this anomaly, however improbable it may have been, will be yet another incremental contribution towards humanity’s growing library of knowledge, taking us one step closer to a more robust and resilient space program, enhancing the overall safety and success of future missions, and improving life back here on Earth.