Rocket Lab figures out what caused its last mission to fail

New Zealand-based space company Rocket Lab is confident it's figured out what caused its last launch to fail.

The upstart firm had its first mission failure on July 5, after 12 successful launches. The Electron rocket launched just fine, but shut itself down before reaching orbit.

"Due to the controlled way the engine shut down, Rocket Lab continued to receive telemetry from the vehicle, providing engineers with extensive data to conduct a robust investigation into the issue," the company said in a statement on Saturday.

"After reviewing more than 25,000 channels of data and carrying out extensive testing, Rocket Lab's Accident Investigation Board was able to confidently narrow the issue down to a single anomalous electrical connection. This connection was intermittently secure through flight, creating increasing resistance that caused heating and thermal expansion in the electrical component.

"This caused the surrounding potting compounds to liquefy, leading to the disconnection of the electrical system and subsequent engine shutdown."

The problem wasn't detected in pre-launch testing, and had never come up before.

"The issue occurred under incredibly specific and unique circumstances, causing the connection to fail in a way that we wouldn't detect with standard testing," said chief executive Peter Beck.

"Our team has now reliably replicated the issue in test and identified that it can be mitigated through additional testing and procedures."

Despite the failure, Rocket Lab - founded in New Zealand, but since 2013 a US company - has been granted approval by the United States Federal Aviation Administration (FAA) to resume flights in August.

"It's a testament to Electron’s track record of reliability that the FAA has approved us for return to flight already," said Beck.

"Electron was the fourth-most frequently launched rocket in the world last year and prior to the anomaly we had deployed 53 customer payloads to orbit without fail. Returning to the pad with an even more reliable vehicle for our mission partners is our top priority."

Rocket Lab's craft do not carry people, so no one was hurt or killed in the accident. 

The company plans to reveal details of its next launch in the next few days.