There’s rarely a quiet moment in Angelia Walker’s office at NASA’s Marshall Space Flight Center in Huntsville, Ala. Propulsion engineers stop by to verify data. Supervisors drop in to check on a report. Managers at NASA Headquarters in Washington call for updates.

“Everyone’s asking questions, keeping up a constant flow of information,” Walker says. “That’s the first sign of a positive safety culture and a healthy engineering environment.”

For Walker, that’s a rewarding thing to see. She manages the Safety, Reliability and Quality Assurance Policy Assessment Department, one of the primary offices of the Safety and Mission Assurance Directorate at Marshall.

Walker monitors Center-wide safety policy and adherence to quality assurance requirements for every Marshall-built system being developed, tested and prepared for flight. Her organization partners with program and project offices to ensure every engine and hardware component and system that leaves Marshall — bound for a test stand at NASA’s Stennis Space Center near Bay St. Louis, Miss., or a launch pad at NASA’s Kennedy Space Center, Fla. — is checked out and ready to safely go to space.

This spring, Walker’s chief focus, like so many of her coworkers, has been STS-114: Space Shuttle Return to Flight. And she’s never been more proud to be part of the NASA team.

“We do an exhaustive amount of checking and rechecking to ensure we’re as safe as we can possibly be,” Walker says. “When it comes to propulsion systems for Shuttle Discovery, we’re there. We’re ready. Let’s fly.”

Those systems are a key responsibility of the Marshall Center. Engineers in the Space Shuttle Propulsion Office at Marshall, supported by NASA and industry all over the country, prepare the Main Engine, External Tank and Solid Rocket Boosters for each Shuttle flight. At full throttle, each of the three Main Engines, mounted in the Orbiter’s aft fuselage, generates more than 375,000 pounds of thrust — four times that of the largest commercial jet engine. The External Tank is the 154-foot-long “backbone” of the Shuttle, delivering its load of fuel and oxidizer, and absorbing the 7.3 million pounds of thrust generated during launch. The two, 149-foot-tall Solid Rocket Boosters generate the majority of the thrust needed to lift the Shuttle from the launch pad, before separating and dropping into the sea two minutes into the flight.

Walker’s organization partners with project teams and makes independent assessments to help ensure all Shuttle propulsion components are ready for launch. And nothing — not cost minimization, not schedule, not an ideal launch window — overrides safety as the final “go-no go” Shuttle clearance, she says.

Born in Phenix City, Ala., Walker was one of seven children of Jimmie and Lilly Goodwin. Taught early by her parents to stay focused on school and her career goals, she graduated from Tuskegee University in Tuskegee, Ala., in 1986 with a bachelor’s degree in electrical engineering. She went straight to work as an electrical engineer supporting design and maintenance of manufacturing equipment for the Polaroid Film Division in Waltham, Mass. A year later, she returned home to Alabama. “I won’t lie,” she laughs. “It was cold up there!”

Walker also wanted to be closer to her then-fiancé, who today is her husband, Sam Walker, senior pastor of the Saint Luke African Methodist Episcopal Church in Birmingham, Ala. She joined the Marshall Center in 1987 as a quality engineer supporting the Solid Rocket Booster Project Office. At the time, NASA was preparing to return to flight following the loss of Shuttle Challenger, and Walker recalls the determination she saw among her co-workers.

“It was a good time to learn,” she recalls. “I was probably a little naĂ¯ve at the time, and it helped me realize you need tough skin in this business. You can’t hesitate when you see an issue worth bringing to light. Lives depend on us. America’s future in space depends on us.” Today at NASA, she says, that attitude is universal. “Personnel at every level are quicker to interact, quicker to challenge traditional procedures in order to make them better and safer.”

That broad devotion to safety makes it easier for Walker to turn over her duties to others this fall. She was selected in early 2005 to become a NASA Harvard Fellow — a follow-up to the leadership program she completed in 2002 at the Federal Executive Institute in Charlottesville, Va. Nominated annually by NASA supervisors and selected by a panel of education administrators at NASA Headquarters, Harvard Fellows spend a semester at the Harvard Graduate School of Business in Cambridge, Mass. Walker will complete the Harvard Program for Management Development program this fall, returning to Marshall in early 2006 to continue her service to the Safety and Mission Assurance Directorate.

“Being selected to attend Harvard is a tremendous opportunity, and a privilege that greatly humbles me,” Walker says. “Leadership is crucial in every organization. I was taught that you can not lead where you do not go, so my personal philosophy is to model the behavior I would like to see.”

No shortage of leadership here. And it’s a good thing — her phone rings again, and there’s a fresh knot of chart-carrying engineers gathering outside her office. Walker’s charismatic smile is back. “Duty calls,” she says, and then gets back to work.

For more information about STS-114: Space Shuttle Return to Flight, visit:

www.nasa.gov/returntoflight

For more information about NASA’s mission and the Vision for Space Exploration, visit:

http://www.nasa.gov