By Jonathan Fildes
Science and technology reporter, BBC News
Watch the robotic plane take to the air
A pair of lightweight, robotic planes have made the first unmanned flights over Antarctica's icy expanses.
Driven by propeller, the machines made 20 low-altitude sorties, including four over the Weddell Sea.
The unmanned aerial vehicles (UAVs) were launched by catapult but flew autonomously until landing.
During some of the test flights the machines were fitted with miniaturised instruments to collect data for use in predictive climate models.
"One of the biggest uncertainties in those models is the physics of sea-ice - how it freezes and how it melts," said Dr Phil Anderson of the British Antarctic Survey (BAS), one of the team that carried out the tests.
"A lot of this happens during the Antarctic winter - the nine-month period when we can't get ships and aircraft to the bases - so we decided to see if we could [collect this data] by robot aircraft."
Tests of the tiny planes, which were designed by the Technical University of Braunschweig (TUBS), started in the Antarctic winter of 2007.
The 2m-wingspan craft are launched by a giant elastic band which catapults them into the sky.
Trials of the UAVs started in the austral winter of 2007
It is initially radio-controlled until it reaches its target altitude of 50m, at which point the autonomous control systems kick in.
"We don't fly the mission with a radio control or with a little video camera onboard," Dr Anderson told BBC News. "It's all up to the little aircraft to make up its own mind."
However, the area in which the plane is allowed to fly is controlled by setting a series of artificial boundaries in its navigation system and the landing must also currently be radio-controlled.
In the future this will be done automatically, said Dr Anderson.
The machines are powered by lithium-ion batteries - similar to those found in mobile phones - which are able to keep the UAV in the air for 45 minutes.
In that time it can cover 45km (28 miles), taking 100 measurements per second.
"The miniaturised instruments can actually measure how much heat is flowing from the atmosphere into the sea-ice," Dr Anderson told BBC News.
This collected data can then be fed into climate models to improve their accuracy.
"We can then run [the models] into the future and get a better idea of what it holds for us in terms of the climate," he said.
Flying the UAVs in the extreme conditions of the Antarctic is not without problems.
As well as the difficulty of handling the machines in thick gloves and mitts, the cold played havoc with the sensitive electronic equipment and even the elastic bungee cord used to loft the craft into the air.
Other scientists are using UAVs to track hurricanes
"We found that it set solid at -10C; so we had to build a very long, snaky duvet cover to go over the bungee just to keep it warm enough, long enough, to do the launch," he explained.
However, Dr Anderson believes the craft will play a big part in future exploration of the continent, surveying hard to reach and dangerous places.
This capability has been exploited for a long time by the military which uses UAVs for surveillance and communication.
As such, research efforts are ongoing around the world to boost the endurance, range and capabilities of craft.
Last year, UK defence firm Qinetiq smashed the official world record for the longest-duration unmanned flight when its vehicle flew for 54 hours during tests.
The Zephyr plane could be used for military applications, as well as for Earth-observation and communications, according to the company.
Earlier this year, the US National Oceanic and Atmospheric Administration (Noaa) announced a $3m (£1.5m) investment into the technology.
It will use UAVs to track hurricanes and Pacific storms, as well as monitor summer ice-melt in the Arctic.