NASA Spins Up New Vehicle Rollover Test

Vehicles were spun, using the HCC at the Goddard Space Flight Center (GSFC), Greenbelt, Md., on a test platform, until inertia and centrifugal force caused them to tip.

NHTSA employs a consumer rating system, the Static Stability Factor, which uses an engineering formula to determine vehicle roll over rankings. NHTSA wanted to research alternative methods for determining rollover resistance. According to NHTSA's system, a one-star rating means a high likelihood of rolling over, and a five-star rating means a low likelihood.

Officials at NASA and NHTSA expect this first-of-its-kind test will enable them to gain valuable safety information about vehicles that move millions of Americans every day. "The NASA project gives us a chance to really explore the potential of centrifuge testing," said Stephen Kratzke, NHTSA associate administrator for rulemaking. "We were lucky to have a sophisticated facility like Goddard's to perform this valuable research. No one else has such a centrifuge, including the Department of Defense," Kratzke said.

NASA uses the HCC to test spacecraft before they're sent into space. Engineers use the HCC to approximate the effects encountered during the rigors of a rocket launch. By testing hardware on a centrifuge, a satellite's structural integrity can be validated prior to lift-off.

The HCC is a big machine, more than 150 feet in diameter, filling an entire circular building. With two powerful motors running at full tilt, the outer edge of the test arm can reach speeds of more than 200 miles per hour, producing a force 30 times Earth's gravity. It is also a finely tuned machine. At rest, the giant multi-ton arm sits on bearings so smooth just two or three people can push it around the room.

"We can control the centrifuge within a hundredth of an RPM (revolutions per minute)," said Carmine Mattiello, section head of NASA's structural dynamics lab at GSFC. "So we can tell exactly when the wheels are coming off the ground," Mattiello said.

A crash test dummy went along for the ride in each vehicle. Sitting in the driver's seat, the "passenger" was an important part of the physical test environment. The dummy, similar in shape and weight of a person, increased the realism and accuracy of the test results.

Since its inception, NASA has pursued a commitment to technology transfer to industry, academia, and other government agencies. NASA makes technology, as well as facilities and expertise, available to help improve safety, security, and quality of life.

For images and information about the roll over tests on the Internet, visit:

http://www.gsfc.nasa.gov/topstory/2003/0212suv.html

For more information about NASA and technology programs on the Internet, visit:

http://www.nasa.gov