Ice-tracking satellite in trouble

By Helen Briggs

A US space agency (Nasa) mission to map the world's ice sheets is in
trouble.
A laser in the satellite's sole scientific instrument is not working and
operations have been put on hold for the time being.

The flagship US mission was launched six months ago to track changes in
the Greenland and Antarctic ice sheets.

The Ice, Cloud, and land Elevation Satellite (Icesat) was sending back
promising data before the problem arose. A review panel has been set up
to decide how to proceed.

Icesat project manager, Jim Watzin, of the Nasa Goddard Spaceflight
Center, hopes a decision will be made this month.

"Right now the mission is temporarily on hold," he told BBC News Online.
"Prior to the anomaly, we were getting excellent results."

Heated debate

The problem is with a laser used to measure the topography of the
Earth's major ice sheets.

Without it, the instrument cannot carry out its detailed mapping of ice
surfaces and their underlying geology.

Scientists have been waiting decades for the launch of Icesat because
the satellite should give the best picture yet of what is happening to
ice in the Arctic and the Antarctic.

There has been heated debate about whether major ice sheets have been
shrinking or growing and what impact this might have on global sea
levels and climate.

"It's a huge disappointment if there's a question mark over its future,"
says David Vaughan, a scientist at the British Antarctic Survey in
Cambridgeshire.

Glaciologists have been gleaning data from similar but less advanced
satellites since the early 1990s.

Read the rest at BBC News
http://news.bbc.co.uk/2/hi/science/nature/3042146.stm


--
Kind Regards,
Robert Karl Stonjek.