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from the forget-the-puncture-kit,-give-me-a-welding-torch dept.
Chainmail tires re-invent the wheel to get future NASA rovers rolling.
NASA has developed chainmail tires with a memory and thinks they'll do the trick for future rovers.
As readers of The Register's coverage of the Curiosity Rover may recall, the vehicle has experienced considerable wheel damage that has led to changes to its route in 2014 and a 2017 software update to preserve the wheels and provide better grip.
Throw in the fact that it's not yet possible to send a spare wheel to Mars and have it fitted, and NASA has a clear need for more robust tires.
Enter a technology called "spring tires" that use a tubular structure of steel mesh – think tire-shaped chainmail - to cushion rovers as they roll. Spring tires have many fine qualities as the mesh forms a pattern that provides good grip on many surfaces. Mesh is also light by nature and can survive some damage. But spring tires don't deform well: if one rolls over a sharp rock, it can acquire a dent - or "plastic deformation" as NASA boffins put it.
The tires use a nickel titanium alloy that can endure plastic deformation.
(Score: 0) by Anonymous Coward on Saturday November 25 2017, @07:01PM (3 children)
We can build a tire for low temperature. It would likely be liquid at Earth temperature, but this is a minor annoyance.
The obvious way to deal with that is to keep the tires at Martian temperature as we prep for launch.
An alternative is to have a thin other layer that is not liquid. After the underlying portion has solidified during the trip and been taken to Mars, we drive the lander around and don't worry about the thin outer layer flaking off. It's a sacrificial tire mold.
Solid is fine, as is a tweel or gas-filled. All will work, and this is a separate consideration.
(Score: 2) by frojack on Saturday November 25 2017, @09:16PM (1 child)
Seriously? Where would that be on the periodic table?
Its not THAT cold on Mars. -107 °C
No, you are mistaken. I've always had this sig.
(Score: 0) by Anonymous Coward on Sunday November 26 2017, @08:01AM
The freezing point for gasoline is somewhere between -40°C and -60°C, depending on the mix and how solid you want it to be. That sounds about right for a Martian tire.
Normal tires would tend to crack at that temperature.
(Score: 0) by Anonymous Coward on Sunday November 26 2017, @04:08AM
Have you cut open a radial tire recently? Under the tread rubber there are two layers of steel wires (at opposite angles), close packed and held in position by the surrounding rubber -- thus "steel belted" tires.
By weaving the two layers in the Rover tires, the wires are no longer close packed, there is lots of open space in the mesh. Even allowing for the extra wire in the Rover tires for the "sidewalls", there is probably less metal in the Rover tire than in a normal passenger car tire. In other words, these Rover tires are very lightweight, no rubber at all to hold the carcass together.
Given the cost to launch anything, I can't see the advantage in lugging heavy rubber tires up into space...until such time that high speed vehicles are being used and high traction on paved surfaces is required.