Enlarge / In January 2018, Boeing shared this photo of the Starliner Pad Abort Test and Orbital Flight Test vehicles under construction in Florida. (credit: Boeing)

In late June, an anomaly occurred during preparations for Boeing’s test of the Starliner spacecraft and its launch abort system. On Saturday, after Ars published a short report on the issue at a test site in White Sands, New Mexico, based on input from sources, Boeing provided additional information about the problem. This story has been updated to reflect the Boeing statement.

The company said it conducted a hot-fire test of the launch-abort engines on an integrated service module at the White Sands Test Facility in New Mexico in June. The engines successfully ignited and ran for the full duration, but during engine shutdown an anomaly occurred that resulted in a propellant leak. “We have been conducting a thorough investigation with assistance from our NASA and industry partners,” the statement said. “We are confident we found the cause and are moving forward with corrective action. Flight safety and risk mitigation are why we conduct such rigorous testing, and anomalies are a natural part of any test program.”

The pad abort test is a necessary part of certifying spacecraft for flight, as it ensures the ability of the spacecraft to pull rapidly away from its rocket in the event of an emergency during liftoff or ascent into space.