Flair for repair

Boeing troubleshooting experts fix Shuttle in-flight anomalies

BY ED MEMI

When something as complex as the Space Shuttle flies, there are unexpected circumstances known as in-flight anomalies that a team of Boeing, United Space Alliance and NASA engineers investigate and resolve after each flight.

IFAs have occurred on every Space Shuttle flight. As the original manufacturer of the Orbiters, Boeing often has the responsibility of investigating and resolving the IFAs as part of its contract with United Space Alliance (a joint Boeing–Lockheed Martin venture that's NASA's prime contractor for Space Shuttle operations). Boeing serves as the technical expert to NASA and United Space Alliance on the design and operation of the fleet to ensure its continued safety, flight readiness, efficiency and overall mission success. Boeing also provides overall Space Shuttle integration and payload support to NASA.

Tim Reith, Boeing Orbiter Integration manager and deputy chief engineer, said although it's not unusual to have IFAs on every flight, they must be fully understood before the next flight.

"When we have an unexpected result, we'll investigate and troubleshoot for the given conditions on whether the hardware acted properly," Reith said. "If the problem can be isolated to a specific piece of hardware, then it will be replaced with a spare. For situations deemed 'unexplained' because the root cause cannot be determined, or if we can't recreate an IFA, we do a thorough assessment of all the things that could happen and determine if we have sufficient redundancy and 'work arounds' and measure the level of risk." In unexplained cases NASA makes the ultimate decision to accept the risk.

Following the Columbia accident, NASA rewrote the definition of IFAs. As a result, more were listed on the last flight, which took place in the summer of 2005.

The process of troubleshooting an IFA begins as soon as Boeing engineers learn about the problem.

"We'll start looking at it right away to determine the impact to the mission," Reith said. "For many of the problems, if there is not a big impact we can often wait until the Shuttle lands to troubleshoot."

All IFAs on the last flight had either a work around or were accepted "as is" with no safety impact.

Troubleshooting usually begins with engineers trying to recreate the problems on the ground to isolate and narrow down the problem. Problem resolution teams define troubleshooting procedures to get a better understanding of the failure.

"If we are successful, then the component is replaced and we go into an investigative phase to figure out why the component failed," Reith said. "Traveling to space is a complicated engineering marvel, and we do all we can to make it as safe as possible. Working with NASA and United Space Alliance on IFAs is just one example of a robust process designed into the Shuttle program."

edmund.g.memi@boeing.com