The University of Colorado at Boulder has been selected by NASA to
build two of the four instruments for a satellite that will probe the
shiny, silvery-blue polar mesospheric clouds that form about 50 miles
above Earth’s polar regions each summer.

The $92 million NASA mission, known as Aeronomy of Ice in the
Mesosphere, or AIM, is part of NASA’s Small Explorer program. The
program was designed to provide frequent, low-cost access to space
for physics and astronomy missions with small- to mid-sized

CU-Boulder’s Laboratory for Atmospheric and Space Physics, which will
control the AIM spacecraft from campus, is expected to receive about
$15 million over the six-year duration of the mission for instrument
design and construction, data analysis and satellite control, said
Professor Gary Thomas of LASP.

LASP was selected to design and build the Cloud Imaging and Particle
Size instrument, or CIPS, which will image the polar mesospheric
clouds and the sizes of particles within them, he said. In addition,
LASP will design and build a Cosmic Dust Experiment to detect cosmic
dust particles entering the atmosphere, said Senior Research
Scientist David Rusch of LASP.

The U.S. Naval Research Laboratory will build an imaging ultraviolet
interferometer known as SHIMMER for the AIM mission, and Utah State
University will build an instrument called SOFIE, an infrared solar
occultation radiometer. The spacecraft will be built by Ball
Aerospace and Technologies Corp. of Boulder.

Thomas, one of the world’s experts on the bizarre polar mesospheric
clouds — also known as noctilucent clouds — said the LASP team is
excited. “We have been planning this mission for four years now,” he
said. “When we received word that we had been selected to
participate, we really whooped it up.”

Slated for launch in 2006, the AIM mission is being led by Principal
Investigator James Russell III of Hampton University in Hampton, Va.
The Co-Principal Investigator is Scott Bailey, a former LASP
researcher who received his doctorate from CU-Boulder in
astrophysical and planetary sciences and now is a faculty member at
the University of Alaska-Fairbanks.

LASP’s Michael McGrath is AIM’s project manager. Co-Investigators on
the 14-member science team include LASP researchers Thomas, Rusch,
Mihaly Horani, Cora Randall, William McClintock and George Lawrence.
The project will involve numerous graduate and undergraduate students
in instrument development, satellite control and data analysis, said

Noctilucent, or “night-shining” clouds occur in the summer in the
mesosphere, which is the coldest part of the atmosphere, said Thomas.
They first were reported in northern high latitudes in 1885. Their
increasing frequency during the 20th century may be related to the
Industrial Revolution, he said.

Noctilucent cloud formation likely is hastened by increasing amounts
of carbon dioxide in the atmosphere, he said. While CO2 is thought
to contribute to global warming on Earth, it ironically cools the
middle and upper atmospheres.

Thomas predicted in 1994 that the noctilucent clouds would continue
to brighten and would be visible over the continental United States
by the 21st century. The clouds, which appear each year in the far
northern and southern latitudes, were spotted over Colorado for the
first time on June 22, 1999, from Coal Creek Canyon near Boulder.

“This was a big event,” he said. “While they are a beautiful
phenomenon, these clouds may be a message from Mother Nature that we
are upsetting the equilibrium of the atmosphere.”
The previous record for the southernmost sighting of these clouds in
the continental United States was in Montana.

The AIM satellite will be launched into a polar orbit about 300 miles
above Earth, said Thomas. “We will be receiving image data from over
the polar caps about twice a day,” he said.