April 25, 2007

NASA Satellite to Study Polar Clouds

VANDENBERG AIR FORCE BASE, Calif. -- A rocket carrying a NASA spacecraft was launched Wednesday on a first-ever mission to study mysterious clouds that float 50 miles above Earth.

The noctilucent clouds, which cluster around the polar regions and can only been seen at night, have appeared more often and grown brighter in recent years. Scientists are puzzled by the changes, but some suggest they may be due to global climate change.

The spacecraft, which will spend two years studying the ice clouds, will try to answer basic questions including why the clouds form and whether human-caused global warming is responsible for the changes. It is dubbed AIM, short for Aeronomy of Ice in the Mesosphere.

"We are exploring clouds literally on the edge of space," principal investigator James Russell of Hampton University said at a press conference earlier this month.

Mounted on a Pegasus rocket that was carried aloft by a special aircraft, it was air-launched over the Pacific Ocean shortly before 1:30 p.m. and boosted into an orbit about 370 miles above Earth.

Launch and mission managers applauded after the spacecraft successfully separated from the rocket. Ground controllers continued to monitor the spacecraft's health.

Everything "appears to be right on the money," said AIM launch commentator George Diller.

The Pegasus rocket, built by Orbital Sciences Corp. (ORB), featured Virginia Tech logos on its side in memory of the 32 students and teachers who died in a school rampage last week. One of the mission's scientists, deputy principal investigator Scott Bailey, works at Virginia Tech.

During the $140 million mission, AIM will photograph the high-altitude clouds and measure their size, air pressure, temperature and moisture content.

Noctilucent clouds were first spotted in the 1880s shortly after a massive volcanic eruption on the Indonesian island of Krakatoa. Space-based satellites have periodically observed the clouds since the 1980s, but the AIM spacecraft is the first devoted entirely to studying them.


On the Net:

AIM spacecraft: http://www.nasa.gov/mission_pages/aim/index.html

Hampton University: http://www.hamptonu.edu