Space News by Jeff Foust — July 22, 2018
Boeing confirmed July 21 that there was an “anomaly†during a recent test of the launch abort engines for its CST-100 Starliner commercial crew vehicle that could delay a key milestone needed for the vehicle to be able carry astronauts.
The incident happened during a hot-fire test of the engines used by Starliner’s abort system, integrated into a spacecraft service module. The static test, which took place in June at NASA’s White Sands Test Facility in New Mexico, was a prelude to a pad abort test of the system planned for later this summer.
“The engines successfully ignited and ran for the full duration,†the company said in a statement. “During engine shutdown an anomaly occurred that resulted in a propellant leak.â€
Starliner uses a “pusher†escape system, with four launch abort engines mounted on the service module that can propel the spacecraft away from its Atlas 5 launch vehicle in the event of an emergency on the pad or during ascent. The engines, which use hypergolic propellants and generate 40,000 pounds-force of thrust each, are provided by Aerojet Rocketdyne.
Boeing didn’t elaborate on the nature of the problem, but other sources, including social media postings several days before the official statement, claimed that a hydrazine valve in the propulsion system failed to close properly at the end of the test, causing the propellant to leak. Boeing didn’t issue the statement until after the first published report about the anomaly by Ars Technica.
Aerojet, in an October 2016 release about an earlier set of hot-fire tests of the thruster, touted the use of “innovative†valves in the launch abort engines. Those valves, said company president and chief executive Eileen Drake, “demonstrate precise timing, peak thrust control and steady-state thrust necessary during a mission abort.â€
More:
https://spacenews.com/boeings-starliner-launch-abort-engine-suffers-problem-during-testing/
