Jul 14 2005
Help is usually just a phone call away when the family car has a flat tire. But what's a rocket scientist to do when new "shoes" are needed for the massive "crawlers" that transport the space shuttle to the launch pad?
That is exactly the situation NASA faced last year as it worked toward the shuttle program's return to flight, now scheduled for July 13. Potentially dangerous cracks were discovered in the huge metal treads that carry the two massive transporters along a rocky, 3-mile path from Cape Canaveral's Vehicle Assembly Building to the launch pad.
A Minnesota foundry was scheduled to forge replacements for the damaged treads. But the on-time shuttle launch was threatened by a global shortage of a seemingly simple, but critical material - sand.
"This isn't just any sand," explains Rechea Hutchinson of United Space Alliance (USA), the prime contractor of the NASA shuttle fleet. "It's zircon, the only kind of sand that can be used in this type of high-temperature casting process."
USA tried to purchase the special zircon sands in Australia and South Africa, but the material was not available.
"And then we discovered that DuPont had a mining operation in Florida - right in our backyard," says Hutchinson. "We asked for their help."
The primary product of the DuPont mine, near Starke, is ore used to make titanium dioxide, a white pigment used in paper, paints and plastics. Zircon and other minerals are mined along with the titanium ore. At the DuPont site, a huge dredge called "The Sandpiper" pumps more than 30 thousand gallons of water and sand every minute. Only two percent of the dredged sand actually contains precious titanium ore and the accompanying zircon.
NASA's urgent request for 225 tons of zircon sand to forge the treads was assigned a top priority by the DuPont Florida plant. In fact, DuPont delivered enough zircon sand to the foundry to complete tread shoe production for both crawlers in December, along with spares to support NASA for the next 100 years.
As an added benefit, the unique particle shape of the DuPont zircon sand used in the tread casting process reduced vibration and noise on the transporter, making the shuttle's trip to the launch pad safer.
United Space Alliance and NASA recognized DuPont's efforts at a March supplier recognition event. "We're proud that DuPont could play a role in helping support the shuttle program's return to flight," said Florida Plant Manager Ken Klein. "DuPont science has always supported America's space program."
http://www.dupont.com/