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."

Comments

Astrobiology Magazine Gets its math wrong

[Lew Pitcher]

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.

What about Mar's thin atmosphere?

[dougmc]

Mar's atmospheric pressure is only about 1% of our atmospheric pressure at most.

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.