Reported October 2006

BACKGROUND: The Prometheus Project is a research team made up entirely of undergraduate students who conducted experiments aboard NASA's "Weightless Wonder" airplane. They explored the use of sound waves to extinguish fires. This could be useful in exotic low-gravity environments like the International Space Station. It could also protect ordinary environments like computer rooms, where using normal chemical extinguishers to put out flames could be damaging. While the student researchers knew sound could cause pressure to drop near a flame, they are working to figure out why exactly this happens. It might be due to a temperature decline at the site of the flame -- chilling the flame -- or a decrease in the concentration of oxygen, which would starve the flame.

CREATING ZERO G: NASA's turbojet simulates a weightless environment by alternating between upward climbs and downward dives to create an arc-shaped flight pattern. It's essentially a 10,000-foot roller coaster, and the arced flight patterns temporarily counteract earth's gravity to create a few seconds of weightlessness over several passes. During climbs, passengers feel almost twice the pull of earth's gravity, followed by a few seconds of zero gravity during the nosedives. NASA uses the plane to familiarize astronauts with the sensation of zero gravity and teach them how to walk in space and on the moon.

ABOUT MOTION SICKNESS: The NASA turbojet is also dubbed the "vomit comet," because as many as 60 percent of passengers may experience motion sickness during flight. The crew has cleaned up an estimated 285 gallons of vomit over the years. Motion sickness is the result of the human body's internal balance system, adapted to function best under earth's gravity. Inside the inner ear are little canals with tiny hairs and fluid that can detect how the body is positioned in space. But aboard the G-Force One, the strength of gravity can be higher or lower than the inner ear is used to, and the shifts can lead to nausea.

WHAT ARE G FORCES? Acceleration is motion in which either an object's speed or direction (that is, its velocity) changes. Mathematically, acceleration and gravity are equivalent, just like energy and mass. A g is a unit for measuring acceleration in terms of gravity. G forces arise whenever something accelerates (as opposed to standing still or moving at a constant speed), because of the corresponding variations in the strength of gravity's pull. The faster something accelerates, the stronger the g forces.

The Acoustical Society of America contributed to the information contained in the TV portion of this report.

If you would like more information, please contact:

Debbie Vi-Vi Nguyen
Public Affairs Officer
Johnson Space Center
Houston, TX
(281) 244-1334
debbie.nguyen-1@nasa.gov

The Acoustical Society of America
Melville, NY 11747-4502
(516) 576-2360
asa@aip.org
http://asa.aip.org