https://techcrunch.com/2021/05/15/rocket-labs-20th-electron-launch-ends-in-failure-with-the-loss-of-its-payload/

Rocket Lab flew its 20th Electron mission on Saturday morning, but the launch ran into a significant issue just after its second stage engine ignited. The engine appeared to shut down just after the ignition, which is not what it’s supposed to do, and which is likely the result of an automated emergency shutdown process that would trigger in case of a system failure. Rocket Lab confirmed that the issue happened shortly after the ignition of the second stage and resulted in the loss of the vehicle and its payload.

The company last encountered a mission failure in July 2020, when the vehicle and its payloads on Rocket Lab’s 13th Electron flight were lost after an engine failure that occurred during the second stage burn. That issue similarly resulted from a triggered safety shutdown, meaning that while the rocket and its cargo didn’t explode, the spacecraft simply stopped operating, but didn’t reach its target orbit or release its payload.