Toward a safer, more reliable engine

Mike Stokes, Boeing Integrated Defense System manager of the Controller Software Laboratory for the Space Shuttle Main Engine program in Huntsville, Ala., said he and his team have been looking forward to flying again since the day Space Shuttle Columbia was lost.

Stokes and the Controller Software Laboratory team develop the Space Shuttle Main Engine Controller software, which controls engine operation during flight. A computer mounted on each of the three Space Shuttle Main Engines monitors almost 90 sensors-including engine pressures, temperatures, propellant flow rates, vibrations and speed-as well as dozens of other engine indications, he said. "The sensors are monitored 50 times per second for the duration of ascent, and this information is then used to control the engine, make assessments of its health, and take any necessary action to keep the astronauts and orbiter safe," he added.

Stokes and his team have spent the last several months making upgrades to the software, which will provide a more safe and reliable engine during liftoff. In addition to the functionality described above, the legacy Space Shuttle Main Engine Controller is getting digital signal processing capability, as part of the first phase of the Advanced Health Management System safety upgrade.

This upgrade will allow sophisticated, real-time analysis to be performed on engine-vibration data collected during ascent, Stokes said. "This analysis will be used to determine if a serious engine problem is beginning to manifest itself and take action to prevent the problem from jeopardizing mission safety. We are looking forward to flying again, and I am very honored to be a part of our continuing presence in space," he said.

-Amy L. Reagan