By Richard Black
Environment Correspondent, BBC News website, in Vienna
The next generation of Antarctic explorers could be robots capable of driving hundreds of kilometres and doing scientific experiments alone.
That was the vision unveiled by US scientists and engineers at a major science meeting in Vienna.
They have built a solar-powered prototype and tested it in Greenland, where it has "exceeded expectations".
Subject to funding, they envisage building and deploying a fleet of five robots by the end of next year.
These could perform scientific experiments where access is currently difficult or expensive.
"There are two basic types of mission scenarios," said James Lever, an engineer from the US Army's Cold Regions Research and Engineering Laboratory in Hanover, New Hampshire.
"One would be to stop the robot en route and take the data you need - things like sampling for bacteria in the snow, measuring the atmosphere, or doing a glaciological survey with ground-penetrating radar," he told the BBC News website at the European Geosciences Union (EGU) annual meeting.
"Then the other side is array-based sensor networks where you would deploy the instruments and then pick them up some time later."
The prototype, built with grant money from the US National Science Foundation, is about one cubic metre in size.
It weighs about 60kg but can carry a payload of at least 70kg and tow a much heavier load behind on a sledge.
The aim was to build a vehicle capable of travelling 500km in two weeks during the Antarctic summer; but on the evidence of the Greenland tests, the researchers believe they have exceeded their goal.
The box is covered in solar panels. The floor houses the control and drive systems, and four ordinary all-terrain tyres make contact with the snow.
Inside is a secure area for any delicate payload.
The robot is designed to be light enough that a small aeroplane could carry it to its starting point.
From there, it would follow a pre-programmed route, calling home via satellite only to download data or if it encountered an unanticipated problem requiring new instructions.
Ponies and traps
It is a far cry from the early days of Antarctic exploration, when the best vehicles available to pioneers such as Amundsen and Scott had four legs and fur to keep them warm.
This concept has more in common with the robotic probes dropped with great success on the surface of Mars by the US space agency Nasa.
And Dr Lever believes his team can learn from problems which arose with the Martian vehicles, particularly when the rover Opportunity became stuck in soft sand last year.
Nasa's Opportunity became mired in soft sand last year
"What we're interested in doing is this 'intelligent mobility' concept - that you're sensing the behaviour of the vehicle, the orientation, its wheel slip, wheel sinkage into the snow, and you're using those diagnostics to interpret how you're doing on the terrain," he said.
"The intent is to interpret what's going on before you get into trouble. They [Nasa] didn't do that; they're doing it now."
The robots are designed to master most obstacles they will find on the Antarctic surface; if they find something they cannot cope with, their computers carry algorithms which should make them stop and check back for instructions.
The team believes its prototype can be turned into something able to survive and work through an Antarctic summer.
Winters are another matter, with temperatures getting as low as -70C, strong winds, blizzards and snow drifts.
One idea is to add a small wind turbine able to provide enough power to keep batteries and electronics warm in the absence of sunlight.
The prototype has cost about $100,000. The team is now looking for more money to develop a fleet of five Antarctic-hardened versions, and has a bid in for $2m with the National Science Foundation.
If this or other grants are forthcoming, robotic rovers could be traversing Antarctica by the end of 2007, enabling them to take part in some of the many hundred research projects which make up International Polar Year (IPY).
David Carlson directs IPY's international programme office, and believes robotic explorers could help with different areas of science.
"One of the things we do on the ice, which takes people and time and fuel and which these robots could do differently, is we sound for the mountains underneath," he told the BBC News website.
"You set off an explosion, monitor the travel time of the waves, it tells you about what's underneath.
"There's a large part of the mountains underneath the ice we really haven't mapped very well. With these little tools you could have a central explosion that is set off by people, and these robots are driving the receivers around in an array - all of a sudden you could get a dazzling map at a much lower personal cost, risk exposure etc."
Other projects are equally spectacular.
"We have a proposal in with Nasa to do sampling of snow for bacteria," said Dr Lever.
"They want to to do a traverse from the South Pole to Halley Station - 2,400 km - for the IPY.
"We're the robotic vehicle that would be used for that; it would be the first ever robotic traverse of Antarctica."