Back in the Space Shuttle tile business

Boeing Integrated Defense Systems employees in Palmdale, Calif., once thought that their tile production days were over when the company decided to move the Orbiter Maintenance and Modification process to United Space Alliance facilities in Florida. But today, Boeing engineers and technicians in Palmdale are back in the business of manufacturing tiles for the Space Shuttle.

That's because the loss of the Space Shuttle Columbia and subsequent tile impact testing recommended by the Columbia Accident Investigation Board have created a requirement for the manufacture of large amounts of tile. In these tests, various substances, such as foam and ice, are being shot from compressed air guns at different angles and speeds onto new tile "targets." Structural and thermal engineering communities are using data from the tests to improve their damage prediction capabilities.

Doug Hollabaugh, Boeing IDS manager of non-metallics in NASA Systems, is pleased that Palmdale employees can support this effort. The orbiters were built in Palmdale and the employees there feel a strong emotional connection to them. "It's as though each one of the orbiters is a family member," said Hollabaugh, who has worked on the program for 27 years. "Anything we can do to help the return-to-flight effort is very rewarding."

Space Shuttle tiles shield the orbiter during re-entry from temperatures as high as 2,300 degrees Fahrenheit (1,260 degrees C). Because the tiles also contribute to the Shuttle's aerodynamic shape, the dimensions and alignment of each tile is critical. Each Space Shuttle orbiter has more than 20,000 custom-made tiles on its lower surface.

Palmdale is expected to produce about 3,000 tiles that will be bonded to large aluminum plates for foam and other debris impact testing. The manufacturing process for tile has been the essentially the same since the early days of the space shuttle program. "Boeing Material and Processes engineering have developed some new substrate materials to give better impact resistance, but the basic process of machining, coating, firing, waterproofing and densifying has remained unchanged," Hollabaugh said.

"We had a learning curve coming back online, even with our experienced people, since it has been a while since we made and bonded tile here," Hollabaugh said. "Our certifications for the people and equipment had lapsed, so part of the process was to recertify the employees, processes and tools.

"People are passionate about this program," he stressed. "Most of these people have spent the majority of their lives working on the orbiters, and they are excited to be part of the team that will put the shuttle back into space."

-Ed Memi