Rocket Lab’s Electron rocket failed to reach orbit after suffering an unexpected engine shutdown mid-flight on Saturday, losing the mission’s payload of two satellites, the company said. The launch from New Zealand was Electron’s 20th, and marked the company’s second mission failure in less than a year.

Electron, a roughly six-story tall rocket with two booster stages, lifted off from Rocket Lab’s Launch Complex 1 on the Mahia Peninsula in New Zealand at 7:11AM ET on Saturday, aiming to send a pair of Earth observation satellites for BlackSky into orbit. Two and a half minutes into flight, the rocket’s second stage booster successfully separated from its first stage and ignited for a few seconds before shutting down, indicating a problem as seen on the company’s launch live stream. Mission control lost telemetry of the booster shortly after.

“An issue was experienced during today’s launch, resulting in the loss of the mission,” Rocket Lab tweeted after the failure. “We are deeply sorry to our launch customers BlackSky and Spaceflight. The issue occurred shortly after stage two ignition. More information will be provided as it becomes available.”

A secondary objective for the mission, dubbed “Running Out Of Toes,” involved a test of some hardware upgrades meant to improve Electron’s reusability, including a new heat shield for the booster’s reentry. The rocket’s first stage booster successfully splashed down in the ocean under parachutes as planned after lofting the second stage toward space, Rocket Lab said in a statement.

The company is working with the Federal Aviation Administration to investigate the cause of Saturday’s issue to correct it for future missions, the statement said. “With multiple launch vehicles currently in production, Rocket Lab is prepared for a rapid return to flight as soon as investigations are complete and any required corrective actions are in place,” it said. No injuries or public damage were reported.

“We will learn from this, and we’ll be back on the pad again,” Rocket Lab CEO Peter Beck said in the statement. BlackSky, the launch customer, retweeted Rocket Lab’s statement, saying: “This is what we have received from Rocket Lab. We will continue to offer updates as we learn more.”

Electron’s last failure occurred in July 2020, carrying and ultimately losing seven satellites after its second stage shut down early. Rocket Lab returned to flight two months later after pegging the failure on a faulty electrical connection, carrying on with six successful Electron missions thereafter. The company has launched 17 successful missions in all.