Cutting The Clatter In Space
 Cleveland - November 24, 1999 - Space may be cold, black, and empty, but it sure isn't quiet. At least not when humans are involved. "It's immensely loud up there," says J. Adin Mann III, an ISU aerospace engineering and engineering mechanics associate professor. "Astronauts come back from the space shuttle with temporary hearing loss, even after a 7- to 10-day mission."

That has serious implications for longer stays, especially on the international space station that's being built. Mann devoted a portion of his recent faculty leave to helping NASA put a damper on all the space racket.

After spending eight months at Royal Appliance, Cleveland, working on the Dirt Devil vacuum, Mann spent four months splitting time between Royal and the NASA Glenn Research Center, also in Cleveland.

"The noise level can get to up to 75 decibels in the space station module that's up there now, and it's being used as the living area," Mann said.

Noise from computer disk drives, cooling fans, and agitators used in experiments are just part of the problem.

Astronauts will literally be surrounded by noisy equipment, which is being built into drawer-like containers that slide into racks in the walls.

"There are even some combustion experiments that use small explosions," Mann said. "The weight requirements are so severe that few noise reduction materials are being used."

Mann worked with teams designing the packaging for experiments, and helped with the mechanical and electronic designs. "Often it's just that the cooling fan noise is loud, and that can be handled by putting sound absorption into the racks," he said.

Other solutions include the use of resilient rather than rigid mounts or adjusting the construction of the racks.

  • Iowa State University
  • Station Portal at NASA