Aerospace Teams Assist in Hubble Servicing Mission

EL SEGUNDO, Calif. (4/1/02) -- Three teams from The Aerospace Corporation played a part in the Hubble Space Telescope servicing mission performed in early March.

One team performed an independent evaluation of risk-management practices and procedures. Team members addressed the benefits and risks of Hubble's risk-management methodology and made recommendations for improvements.

Another Aerospace team performed an independent evaluation of Hubble's reliability model and predictions. The team enhanced the reliability model with additional and improved reliability data and improved the reliability prediction methodology.

A third team performed a data search related to a transistor failure that occurred on the space shuttle Columbia.

Fourth Upgrade Mission

This was the fourth space shuttle mission devoted to upgrade and enhancement of the 12-year-old space telescope.

Objectives of the 11-day mission, which began March 1, were to replace Hubble's solar arrays, its power switching station and one of the four primary pointing devices, and to install a powerful new optical instrument called the Advanced Camera for Surveys.

"The Hubble team's ability to plan for and execute complex on-orbit servicing missions is built around fundamental risk-management practices," explained Mike Weiss, Hubble deputy program manager at NASA Goddard Space Flight Center, in discussing Aerospace support in the area of risk management.

"To a great extent," he said, "we use reliability models and predictions to understand and predict health and safety risks to the Hubble vehicle. Aerospace provided valuable oversight for Hubble's risk-management implementation and reliability modeling."

Data Search

The company's data search was in response to a request from NASA Johnson Space Center's Engineering Directorate and Independent Assessment Office.

The Aerospace team used the company's parts-history database to identify hundreds of previous failure reports related to the space shuttle's transistor. The Aerospace data search helped to identify the scope of the suspected problem.

After NASA examined every location within the space shuttle for suspect transistors and determined that all applications were either noncritical or were multiply-redundant, the orbiter was cleared for flight.

"Aerospace information was vital in helping to guide the evaluation," said a NASA Johnson representative.