Slashdot Mirror
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."
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!"
For some reason I remember back in the late 1980s the University of Arizona students considered doing something like this. Rather than simply having the wind roll it around, they thought about using pumping fluids. (iirc). They decided against the ball design for fear that it might get stuck somewhere and couldn't get out.
Instead they came up with 'rover' that had two wheels that were inflated in pie sections. It looked like a giant axel with no car attached. It had a nonrotating middle where the instruments, etc, were supposed to be placed. IIRC, they actually tested it out in the desert.
A quick google doesn't turn up anything. IIRC, it was called the 'Mars Ball' and I read about it in Discovery magazine circa 1988, but I might be off +/- a couple years. At the time, I loved it. It was simple, yet seemed rather well thought out and flexible.
Anyone have any good pictures or articles online?
Do you know why the road less traveled by is littered with the bones of the unwary?
They are referred to as 'rover' in the series..
Rather scary creatures... Much more so then the orginal 'robot car'that Patrick had envisioned...
---- Booth was a patriot ----
Is it going to get to Mars in 3 weeks now too? Let's do some quick rover math...
Distance to Mars 34.65 million miles Original Rovers got there in 3 weeks according to NASA
3 weeks (21 days) 504 hours divided by distance? 69023 miles per hour
Those are some fast little 'ships' even if it took 6 months (180 days) it would have to travel at 8020.8333333333333333333333333 to get to mars. A year? Oh you get the point. It's a conspiracy I tell you
MoFscker
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.
From the article: A 6-meter diameter ball on Mars could accelerate to about 10 m/s (22.4 mph) pushed along by Martian afternoon winds of 20 m/s (44.7 mph).
c++;
In fact, the prototype made it across a relatively well-mapped out ice sheet. We, on the other hand, can only do our mapping of the martian surface by satellite. A relatively shallow crater or unmapped obstruction still strikes me as being a show-stopper. This may well not be the case at all, but I'd like to know why -- maybe Surveyor has a high enough resolution that this is not an issue. If not, maybe future orbiters are planeed that do.
Roving Web-Teleoperated Robot
"The Prisoner" was the first thought that came to my mind also:
http://www.retroweb.com/prisoner.html
Actually, 3 satellites are not sufficient; there are no orbits (geosynchronous or otherwise) that are always line-of-site from the poles (where this vehicle would be used). Thus, more than 3 satellites would be required to form a GPS system, at least if you want it to always be available. I'm not really sure, but the actual number required might be 7; or more depending on how much atmosphere your signal can cut through.
--
For news, status, updates, scientific info, images, video, and more, check out:
(AXCH) 2004 Mars Exploration Rovers - News, Status, Technical Info, History.