It seems Curiosity’s wheels are wearing out faster than expected and engineers want to know why.
It seems Curiosity’s wheels are wearing out faster than expected and engineers want to know why.
The increasedwear recently appears to be because the rover was traveling over rougher terrain. Nonetheless, JPL engineers are going to monitor the rover’s travel and wheel damage more closely in order to gauge that wear better for future travel.
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It seems Curiosity’s wheels are wearing out faster than expected and engineers want to know why.
The increasedwear recently appears to be because the rover was traveling over rougher terrain. Nonetheless, JPL engineers are going to monitor the rover’s travel and wheel damage more closely in order to gauge that wear better for future travel.
Readers!
Please consider supporting my work here at Behind the Black. Your support allows me the freedom and ability to analyze objectively the ongoing renaissance in space, as well as the cultural changes -- for good or ill -- that are happening across America. Fourteen years ago I wrote that SLS and Orion were a bad ideas, a waste of money, would be years behind schedule, and better replaced by commercial private enterprise. Only now does it appear that Washington might finally recognize this reality.
In 2020 when the world panicked over COVID I wrote that the panic was unnecessary, that the virus was apparently simply a variation of the flu, that masks were not simply pointless but if worn incorrectly were a health threat, that the lockdowns were a disaster and did nothing to stop the spread of COVID. Only in the past year have some of our so-called experts in the health field have begun to recognize these facts.
Your help allows me to do this kind of intelligent analysis. I take no advertising or sponsors, so my reporting isn't influenced by donations by established space or drug companies. Instead, I rely entirely on donations and subscriptions from my readers, which gives me the freedom to write what I think, unencumbered by outside influences.
You can support me either by giving a one-time contribution or a regular subscription. There are four ways of doing so:
1. Zelle: This is the only internet method that charges no fees. All you have to do is use the Zelle link at your internet bank and give my name and email address (zimmerman at nasw dot org). What you donate is what I get.
2. Patreon: Go to my website there and pick one of five monthly subscription amounts, or by making a one-time donation.
3. A Paypal Donation or subscription:
4. Donate by check, payable to Robert Zimmerman and mailed to
Behind The Black
c/o Robert Zimmerman
P.O.Box 1262
Cortaro, AZ 85652
You can also support me by buying one of my books, as noted in the boxes interspersed throughout the webpage or shown in the menu above.
Those holes don’t look good.
You can even see the ring around the tire made by the attachment ring on the inside of the wheel.
Eventually it will start to come right through the “tire” if you want to call them that.
All this trouble just to save weight. They are driving a ton of rover on paper thin tires. Over rocks that have never really been through an environment that would have smoothed them out.
Its like driving on sandpaper and hopping it doesn’t eventually wear through the tire material.
Three miles and its starting to fail.
I would have gone with one less camera or something in order to keep the tires working.
Think of it this way.
The flat parts of that tire are as thin as a business card.
And when dropped on sharp rocks they have no way to absorb the impact.
A rubber coated tire has the rubber to absorb the impact and spread it out over a larger portion of the surface.
Think of this.
A standard rubber car tire deforms as it contacts the ground. Thus it will have anywhere from 4 to 6 inches by 6 to 8 inches of surface area contacting the ground depending on the tire and air pressure. And as it rolls over a sharp rock the tire gives way and forms around the sharp object.
But these solid tires have no give. On a hard flat surface they have a contact area of less than an inch square and in some cases only a fraction of that. Such as when it is on one of its “treads”.
These solid tires work great on sand. the sand molds around the tire and spreads the contact area out to a safe level. But as soon as it has to go over a hard object that area is immediately reduced to a pencil point of area.
Lets assume each wheel carries the same weight of the rover. 2000 lbs divided by 6 wheels would be about 330lbs per wheel.
All 330lbs would be concentrated into a pencil tip sized area. An area only as thick as a business card.
How hard is it to push a nail through a coffee can?
The cream of the crop of our engineers thought of this and forgot to test it out.
A logical guess would be the engineers considered that, perhaps they thought that the weaker Mars gravity would reduce the impact of sharp rocks enough….
http://www.planetary.org/blogs/emily-lakdawalla/2013/10022101-theres-a-hole-in-the-wheel-dear-liza.html
This engineer is of the opinion that even if the wheels fell off the rover would still be able to move on those little bent spring/suspension things that attach the wheel rim to the hub.
The problem with her idea is that if the rover ever does goes over soft ground it would then sink and be permanently stuck.
And it has miles of sand to drive over to get to the mountain its supposed to drive up.
They were made that thin just to save weight. Thats all and even NASA admits it.
NASA needs to get off its single monolithic launch idea and embrace the idea that they can make more than one launch for things like this.
Launch the payload you want to get to Mars into LEO and then launch a rocket engine to boost it out of orbit and on to Mars.
As long as NASA plans for it they have shown the ability to dock anything to anything in orbit remotely and or autonomously.
Its either that or just launch the needed payload on a bigger rocket. They will just have to accept that at times some possible payload capacity might not be used. They don’t have to fill it up to 100% capacity in the false thought that its saving something.
In the end, from everything I have found out about the thickness of the wheels. They only saved a few ounces of weight. They could have doubled the thickness for just a few ounces.
I’m more than likely making something out of it than it really is, but really, can’t they just add a few more pounds of fuel to the rocket to cover the few extra ounces and fire it a little longer?
Thats all the private industry is doing.