As space missions become more enterprising, the technology driving the systems becomes more demanding. The next round of planetary Lunar and Mars rovers must be able to survey more, quicker, and with little input from their commanders on earth. In effect they need to become autonomous; thinking for themsleves, driving without human command, sensing the landscape, assessing dangers and navigating safely in order to uncover the fundamental questions they have been sent to answer.
This technical wizardry cant be be left to just happen on an alien planets surface and has to be thorougly tried and tested long before launch. Ruatherford Appleton Labs in Harwell have been developing just this technology driven through a multinational project funded primarily by NASA but with a significant input bfrom the European Space Agency (ESA) and companies such as British Aeropsace Engineering (BAE) and Mcdonnel Douglas. Their testing includes settings tasks on real terrestial surfaces that simulate the martian landscape and this is where QuestUAV systems have been empolyed. For every task, a detailed three dimensional map, a Digital Terrain Model (DTM) is required of the lanscape.
The partnership for us started after staff at RAL systematicallly looked at every UAV system available on the market, in both the rotary and fixed wing classes. After a detailed analysis they chose to ask QuestUAV to provide a sample DTM of one of theri test sites. Despite the DTM being conducted in high wind situations (est 60 mph gusts) the resuts were successful and and DTM was produced. RAL were very happy with this - their very first successful DTM -and so the relationship developed between RAL and QuestUAV. Training took place over Jan, Feb and March and in May they departed for the pre test sites in the Attacama desert where NASA had set the gruelling tasks that the navigation systems would have to prove themselves on.
The Atacama desert is a hostile place; high, dry, rocky and gritty. Landings are harsh and the air is thin. At almost 10000 ft with little graphical information to bind overlapping images, it provides a real challenge for an unmanned aircraft to operate successfully. However the crew, Prof Brian Maddison, Dr Aron Kisdi and Dr Wayne Tubby performed an excellent job, learnt quickly and brought images back that can only be described as stunning. There were issues though. The harsh surface and thin air made for rough landings and the foam nose of the aircraft became increasingly pitted. Though the nose is designed to be sacrificial the concern was that the continuous impacts with rocks would eventually break something off. In hindsight it was just fine, but subsequent modifications added a stronger "Skid Pan" to the base of the nose that worked well. Also the mixture of sharp and grity sand got everywhere. Each landing threw up a mini duststorm that got into anything that was exposed (both internally and externally). Landings also took a toll on propellors. Propellors are changed in a few seconds so its not a problem, as long as it is noticed. On the last flight damage probably wasn't picked up and when the rate of climb was significantly reduced after takeoff and the UAV seemed to be performing poorly, the pilot elected to abort the flight and conduct an emergency landing. The UAV landed fine, though probably fast and directly into a rock field, suffering mild damage to the body. Wisely the crew chose to cease flying (though the damage could have been reapired in field) and with suitable testing and imaging complete in this phase of the project the crew decided to conduct final repairs back in the UK.
QuestUAV got the aircraft body back for repairs a few days later, tidied it up, beefed up the nose and sent it back ready for round two of testing back in the Atacama desert in early June.
Over a three week period it performed faultlessly on all twelve flights, even manging days with high winds (over 40 mph). The spare UAV sent out to accompany it was never needed. The cameras got very dusty, but performed flawlessly. The motor had the harshest of lives but never missed a heartbeat. The UAV got pumellled and even accidentally flown into the ground at cruising speed, but flew again without a hiccup. (The crew, looking down on the UAV from what they thought was high ground, mistook sloping ground for flat gound and impacted the UAV on the upslope of the desert floor). Damage? A cracked £6 propellor.
It was all the news that we hoped for but didn't dare to ask ... that the QuestUAV 200 had not only survived, but passed wiyh flying colours. We even got the message that Gianfranco, the head of ESA Robotics, was pretty impressed with the UAV ... he was convinced it would not manage the harsh tasks chosen for it. But it did.
RAL will be composing the DTM's over the next months and the results will eventually form a research paper earlt next year. We are now working with RAL on a project to integrate the very capable (and very expensive) Tetracam Mini MCA into a QuestUAV 300 for a number of spectrometry tasks set aside for it in the coming months.
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