CONTACT: GARY GALLUZZO
100 Old Public Library
Iowa City IA 52242
(319) 384-0009; fax (319) 384-0024
Release: Feb. 23, 2001
UI researcher prepares first experiment conducted on International Space
IOWA CITY, Iowa -- When the first crew of the International Space Station
personnel conducts its first physical science experiment on March 3, 6 and
7, the University of Iowa will be represented.
That's because UI physics and astronomy professor John Goree is a co-investigator
for the Plasma Crystal Experiment (PKE), an investigation being conducted
in collaboration with German and Russian researchers.
Scheduled for a Feb. 25 launch and transport to the space station aboard
a Russian unmanned Progress rocket, PKE is basic research aimed at using a
low gravity environment to better understand the structure of matter. The
experiment's hardware is contained in two boxes, one cylindrical in shape
and a little larger than an office trash can and the other resembling a desk
"We will begin with a plasma, or electrically charged gas, into which
we will introduce plastic microspheres about 10 microns in diameter, smaller
than the diameter of a human hair," Goree says. "The microspheres
will disperse in the plasma and become similarly electrically charged. They
will repel one another so that they arrange themselves in a fixed spacing,
like the atoms in a crystalline lattice such as ice, sugar or diamonds."
Under Earth-bound laboratory conditions, gravity causes sedimentation of
the particles, resulting in a thin horizontal layer at the bottom of the plasma.
The particles in the microgravity of the International Space Station will
be imaged with a camera and laser illumination so that particles in the suspension
can be viewed and their positions and velocities recorded.
Goree notes that in one sense, he is imitating nature because the PKE experiment's
so-called "dusty plasmas," in which plasmas contain small particles
of solid matter, exist naturally in the rings of Saturn and the tails of comets.
Goree's work on the Plasma Crystal Experiment is funded by a $459,000 NASA
Microgravity Program grant that runs from January 1, 1998 through December
31, 2002. His colleagues include Principal Investigator Gregor Morfill, professor
at the Max Planck Institute for Extraterrestrial Physics, Garching, Germany;
and Principal Investigator Vladimir Fortov of the High Energy Density Research
Center, Moscow and vice president of the Russian Academy of Sciences.