Returned to flight

Space Shuttle Discovery's return to Earth meant a successful close to the STS-114 mission—and to the efforts of hundreds of Boeing employees involved in getting the spacecraft back in the sky

BY ED MEMI

A light appeared high in the early morning sky over Edwards Air Force Base, Calif., on Aug. 9. Faint at first, it grew brighter as it slowly descended through the predawn darkness.

That light came from Space Shuttle Discovery during its return to Earth. The approaching, intensifying light not only signified the descent of the shuttle before the spacecraft smoothly landed on an Edwards runway, but it served as a metaphor for the Boeing teammates who worked on the shuttle. It was the light at the end of their two-plus years of work.

Discovery had performed almost flawlessly during its 14-day mission. "Welcome home, friends," radioed astronaut Ken Ham from Mission Control in Houston to the STS-114 crew after Discovery rolled to a stop.

For the roughly 1,800 Boeing teammates who work on the shuttle and related programs, the mission culminated two-and-a-half years of hard work to help NASA's flagship fly again. "With this flight, we've taken a major step forward in making the Vision for Space Exploration a reality," said Mike Mott, Boeing NASA Systems vice president and general manager. "We must remain focused and remember that Return to Flight is a process and not a mission."

STS-114, NASA's first shuttle mission since the loss of Shuttle Columbia, was commanded by veteran astronaut U.S. Air Force Col. Eileen Collins. The mission, the first of two planned "test flights," delivered much-needed supplies and equipment to the International Space Station, while testing new tools and procedures to enhance shuttle safety (see box at right). "We had a fantastic mission," Collins said shortly after the landing.

Work marathon

A work "marathon" has been run by thousands of Boeing teammates since a chunk of fuel tank insulating foam struck Columbia's left wing during ascent to orbit, causing the craft's breakup on its descent from space on Feb. 1, 2003.

Since the accident, the external tank, which holds liquid hydrogen and oxygen for the Rocketdyne-built main engines, was redesigned to prevent foam from shedding on future flights.

Virtually all of NASA's post-Columbia improvements to the external tank worked as expected during Discovery's launch. Still, several large pieces of foam debris fell away from the tank during ascent, proving additional work is still needed. NASA has pulled together a special team to fix the foam loss and is now targeting March 2006 for the next Space Shuttle mission launch.

"Return to Flight means that we have met one of our obligations to the crew of Columbia and the American people to continue the vision for space exploration," said Al Fazio, requirements integration manager, Boeing Florida Space Shuttle Operations.

The Boeing team's efforts included design, development and testing of orbiter systems modifications, verification of orbiter flight certification, and systems and payload integration. Boeing also supported the launch's flight and processing activities.

Using companywide resources, Boeing engineers assessed the ability of the Orbiter to tolerate damage from foam and other potential debris during launch. In addition, engineers conducted extensive wind-tunnel tests for the first time in 17 years while analyzing the airflow around the modified external tank as the vehicle accelerates to more than 17,500 mph (28,200 kilometers per hour) on its way to space. And, to better understand the effects of multiple design changes and how debris might travel should it be released from various locations, the Boeing team conducted literally millions of computer simulations of shuttle ascents.

Keeping a close eye

The Space Shuttle was launched with unprecedented scrutiny from both ground-based and airborne cameras as well as onboard impact sensors located in the wing leading edge. Boeing engineers helped integrate the new sensors and cameras on both the Orbiter and the external tank. These improvements provided NASA and the industry team with real-time data and high-resolution imagery during ascent and immediately following Orbiter separation from the external tank once safely in space.

The STS-114 flight carried a new 50-foot (15.2-meter) orbital boom tipped with instruments to scan Discovery's Thermal Protection System (TPS) for damage. Besides overall integration of the new boom, Boeing designed and built the Manipulator Positioning Mechanism to secure the boom in the payload bay and ensured ascent and landing loads were within safety margins.

The boom performed flawlessly on orbit and was a useful tool in evaluating a "puffed up" thermal blanket as well as heat tiles and wing leading edge panels. The imagery gave NASA an unprecedented ability to scan and determine the excellent health of the orbiter's TPS prior to reentry.

'Safest mission ... ever'

"Discovery's flight was the safest mission we've ever flown. NASA went beyond the recommendations of the Columbia Accident Investigation Board (CAIB) with a number of 'raise the bar' initiatives, a milestone-driven approach for all launches to avoid schedule pressures and an extensive array of safety improvements," said former astronaut Steve Oswald, vice president and Boeing Space Shuttle program manager. Oswald lauded the extensive support provided from throughout Boeing for the return to flight. "I can't remember anything that we asked for that Boeing didn't provide us as quickly as possible and in whatever amount we needed."

Boeing participated in a design certification review that examined the major systems on the Space Shuttle to ensure that nothing was being operated outside the original design parameters without being completely recertified.

The NASA-appointed Return to Flight Task Group, headed by former astronauts retired U.S. Air Force Lt. Gen. Thomas P. Stafford and Col. Richard O. Covey, who was loaned from Boeing's Homeland Security organization, monitored NASA's compliance with 15 safety recommendations made by the CAIB. The group endorsed NASA's efforts on all recommendations.

Boeing engineers played a substantial role in seven of the 15 mandatory recommendations while supporting 14 "continuing to fly" recommendations from the CAIB. Boeing assisted NASA and its industry partners by developing initial on-orbit repair capabilities to the TPS, evaluating system design and operational changes, revalidating potential hazards and playing an integral role in the Flight Readiness Review, the final NASA-led assessment of mission preparation activities before Discovery launched.

All the work by the entire shuttle team gave the crew confidence in the system.

"In this job we are at the tip of a pyramid of thousands and thousands of people," said Discovery Pilot Jim Kelly at a post-landing news conference. "And you can't sit at the top without trusting them."

edmund.g.memi@boeing.com

Amanda Smoke and Susan Wells contributed to this report.