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Tumbleweed Rover for Marathon Martian Journeys
An anonymous reader writes "A prototype Mars rover, the Tumbleweed, has completed its 40 mile trek across the Antarctic, driven only by winds even in rough terrain over eight days. While the current rovers are designed for flat, equatorial regions, the tumbleweed design is geared to cover longer distances across what many consider the more interesting and dangerous polar regions on Mars."
More like anti-escape orb from The Prisoner.
Rover Bowling!
Along the way, the beach-ball-shaped device, roughly two meters (six feet) in diameter, used the global Iridium satellite network to send information about its position, the surrounding air temperature, pressure, humidity and light intensity to a JPL ground station.
Note that the wind-propelled rover used an existing overbuilt satellite constellation to communicate its data back to the engineers. The implication there is that the rover couldn't use the sort of non-androsynchronous communications satellite that is currently available on Mars. So unreliable communications is one notable problem.
Also, look at the data that were being recorded... position, air temperature, pressure, humidity, and light intensity. Position is likely hard to determine without a Martian GPS system. Even so, the rest of those parameters can be deduced from current orbiters, especially "humidity". I can tell you that now -- it's somewhere close to 0%. It's a dry heat^w cold.
The nature of the object means that those are pretty much all the sensor readings you're going to get, too... add pretty pictures to the mix, of course. But this isn't something that can bore holes in rocks or take detailed spectra of interesting spots, because there's no way to anchor the ball to the ground.
If it can be done "fast and cheap", go for it. It might give some good close-up photos of places to send a more capable lander. But I'd suggest launching another Beagle (with airbags) first, if we're wanting best bang for the buck.
Stressed? Me? Of course not. Stress is what a rubber band feels before it breaks, silly.
I built a robot for a class once. And after completing it, I have much more respect for the people trying to design these things.
It's not so hard to make a robot that works. It's all the possible problems that make it hard. And if your robot happens to be on Mars when it breaks... you're SO screwed!
All the little things... unanticipated terrain, sensor malfunction, wheel gets stuck... the list is endless. Of course, during my project I kept to the smooth carpet and just moved the robot whenever something happened. But these guys have got their work cut out for them.
No pressure, its just a 3 million dollar robot!
Slashdot Syndrome: the sudden, extreme urge to correct someone in order to validate one's self.
The ultra-durable ball reached speeds of 30 kilometers per hour (10 miles per hour) over the Antarctic ice cap
Do you think that someone should tell Astrobiology Magazine that 30 kph is about 18 mph? That's almost double the mph that they give the rover credit for.
"values of beta will give rise to dom!"
The article says that they wanted to test the durability of the design in a cold environment. That's proven to be a success. Don't start talking about the limitations of the device based on one experiment. The point was to test how well the wind transport design will work, and track its position using a simple, cheap, and pre-existing satelite network. This test is but one test in an ongoing process.
AccountKiller
This means that it would require a wind about 10x as strong as here to produce the same amount of force on something like this rover.
Fortunately, the gravity on Mars is about 1/3rd of ours, so in theory you'd need only about 1/3rd as much force to move your giant beach ball, so I guess you could get the same amount of movement on Mars as you do here with only 3x as much wind.
(Some more thoughts along this line can be found here, which is a page about a simulated plane flying on Mars.)
Apparantly Mars does have strong winds, so maybe this isn't as crazy as I first thought :)
As an example, the article talks about a 20 m/s wind on Mars -- that would produce the same thrust on a stationary object as a 2 m/s wind would here on Earth -- not very much. But once the object started moving, the thrust would not drop off as fast as it does here (after all, wind won't usually push something faster than the wind is going) so if the ball was light enough, it might actually move at a decent clip. But it would have to be very light.
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For news, status, updates, scientific info, images, video, and more, check out:
(AXCH) 2004 Mars Exploration Rovers - News, Status, Technical Info, History.