You are not logged in.
On a future Martian colony, which do you think would be more likely to be used on ground transportation vehicles; tires or tracks-or some other method of moving along the ground?
Personally, I favor tracks as they require no synthetic rubber and no material to inflate them. Which do you think would be most practical?
In the interests of my species
I am a firm supporter of stepping out into this great universe both armed and dangerous.
Bootprints in red dust, or bust!
Offline
Blimps > Ground Transport.
Since tracks are slow and if you're going somewhere on Mars you'd better be there quick, I say some Magnesium variant of tires.
The MiniTruth passed its first act #001, comname: PATRIOT ACT on October 26, 2001.
Offline
Both have their problems... Tires run flat, tracks break.
What about a 'combination' Dunno how to explain this very good...
Imagine an old horsecart wheel. Replace the spokes with either springs or pneumatic bars. On the end you put rectangular 'thread segments' on a flexible mount.
Looks like a wheel (circle) AND Threads, but circular.
Advantage in contrast to classic threads: you can break some parts, and still be able to drive. If one breaks it's no big deal, given enough 'spokes'
(must've read this somewhere, can't be i came up with this myself, hardely awake....)
(Edit, and i think this is 'my' idea: must be possible to control individual pneumatic rods, would give you very adaptive 'Threels' (in want for a better word)
Some kind of active suspension, but for segments of the wheel, instead of the whole wheel...So you could make it go 'flat' for better grip , angle the individual plates for better bite into dusty slopes... let it react to individual small boulders for extra-smooth drive...)
Offline
Hmmm attemt to ASCII graphics....
Doesn't work out... My 'masterpiece' ends up like this...
//
XX___/
Offline
I think I've seen an 'artist rendering' of the tire/track you are talking about. It sounds like a good idea to me. I think the super-active suspension is a bit much, though. The more complicated something is the more likely it is to break.
Offline
Tires on Mars shouldn't be inflated because they could go flat. The lunar rover had open mesh tires that could bend and flex, absorbing bounces as they went. Something like that would work.
If a vehicle has six wheels, also, it can afford to have trouble with one or two before it is in trouble.
-- RobS
Offline
What about a Mars-bike?
Two or three wheeled motor bike, like an ATV?
Someone build me one.
Offline
here's a good moonbuggy page with picture of the wheels made from spring steel with titanium cleats shaped like chevrons. http://www.hq.nasa.gov/office/pao/Histo … h23-3.html
I vote for moonbuggy style wheels on land rovers with 2,3,4 or 6 wheels and tracks for heavy mining equipment
Offline
Rubber or synthetic base tires don't have to be Pneumtic based. But I believe tires to be the best solution. For lightwieght quick transportion an Axled tire setup would be the simplist and easist way to do it. It also would be the most straightforward to maintain. The more complex a system is, the more bugs that have to be worked out and more wierd and stange break situations you get into. I am into Rock-Crawling. This is a form of offroading that has a goal of going over obstacles that would be impossible in a normal vehicle.
A convential system like this would also be nice due to the ability to CNC new parts easier. The other thing is with tires of a synthetic/rubber base, the passengers will be very thankful the ride qualtity will be much better. Unless you are driveing on ice, I don't see a need for stud based metallic tires or cleats.
One last thing is minimal environmental impact. a standard tire of some sort or deviation will have the lowest impact, then a standard track. Anything Studded or Cleated will tear the %$# out of whatever you are driving on.
Just my 2 cents.
We are only limited by our Will and our Imagination.
Offline
i think maybe both, 2 tracks on the back of the vehical and 2 wheels on the front.
[img:sig_uid][url]http://www.danasoft.com/sig/Digital_Wolf.jpg[/url][/img:sig_uid]
Offline
Tracks are energy hogs compared to wheels. Using inflated tires adds complication that is just not necessary. I like large, 5' tall, solid, thin, aluminum half spheres with rounded rubber grips. Each rubber grip could have a hollow interior with some kind of cushioning (foam?) material. Most of ride quality would come from the suspension though, and not the wheels.
Offline
I think this has been touched on before in another thread but how well does rubber (or synthetic rubber) stand up to large temperature variations - particularly at the low end of the scale?
I believe -90 deg.C is not uncommon on Mars at night.
???
The word 'aerobics' came about when the gym instructors got together and said: If we're going to charge $10 an hour, we can't call it Jumping Up and Down. - Rita Rudner
Offline
I think this has been touched on before in another thread but how well does rubber (or synthetic rubber) stand up to large temperature variations - particularly at the low end of the scale?
I believe -90 deg.C is not uncommon on Mars at night.
???
*Well, not that I know much about this topic (because I certainly don't), but I recall news reports of tires freezing and shattering in Alaska when the temps (not windchill) hit -70 F.
Of course, I'm not sure what tires are made of *exactly*...
Hope this helps.
--Cindy
We all know [i]those[/i] Venusians: Doing their hair in shock waves, smoking electrical coronas, wearing Van Allen belts and resting their tiny elbows on a Geiger counter...
--John Sladek (The New Apocrypha)
Offline
Ooh, another technical question. I looked up what goes into tires. It's mostly rubber, with layers of polyester or nylon fabric to make radial tires, and woven steel fibres to make steel belted tires. The rubber is vulcanized to make it stronger: it's heated with sulphur to cross-link the molecules. Then other stuff is added: [http://www.trucktires.com/us_eng/librar … s1/ra7.asp]How to make a tire. Natural rubber is better in cold, synthetic rubber (usually neoprene) is better in heat. Recycling of tires often starts by cryogenically freezing to make it brittle, then crushing it. One recycling web site in the [http://mir.udmweb.ru/eng/go.aspx?pageid=147]Republic of Udmurt (a province of Russia, I never heard of it before either) says tires become brittle between -40? and -70?C, but a [http://home.snafu.de/kurtr/str/en_sr.html]German recycling site says -80?C. I hope western tires don't become brittle until lower temperatures: here it got down to -40.6?C on January 29, and -41.0?C on January 30. I guess a recycling plant will cool tires below the operational temperature; they want tires to break easily. But Mars Pathfinder recorded a low of -77?C during the 3 days it operated, and Viking 2 recorded a low of -111?C while operating for more than a Martian year.
Offline
Thanks, Cindy and Robert! (Both mines of fascinating information in their own inimitable ways. )
It sounds like we'll need specially prepared rubber or we'll have to stick with some other solution, like metal tracks or mesh.
If we can't rely on rubber to help mop up the bumps, I suppose we'll have to rely more on the suspension. It just occurred to me that perhaps even steel springs might be more prone to breakage if expected to compress and decompress while very cold ( .. say, -80 deg.C or colder).
Perhaps even gas-filled shock absorbers and other mechanisms with critical seals might seize up and fail in some of the coldest regions of Mars.
Has there been a lot of research into this sort of thing in places like Siberia, Alaska, and northern Canada?
???
The word 'aerobics' came about when the gym instructors got together and said: If we're going to charge $10 an hour, we can't call it Jumping Up and Down. - Rita Rudner
Offline
[=http://www.newmars.com/forums/viewtopic.php?t=3460]Previous thread about machines, etc.
*Shaun writes: "Has there been a lot of research into this sort of thing in places like Siberia, Alaska, and northern Canada?"
Maybe this thread (long buried) will be of assistance (?). In my 2nd post in the thread I mentioned the vehicles I saw in a documentary on the Discover Channel. At the time I searched Google to find more precise information (I didn't take notes while watching the documentary), particularly the names of those machines (red vehicles with big spikes, and another type of vehicle)...with no luck. Maybe someone else here can fill in the gaps abit.
--Cindy
We all know [i]those[/i] Venusians: Doing their hair in shock waves, smoking electrical coronas, wearing Van Allen belts and resting their tiny elbows on a Geiger counter...
--John Sladek (The New Apocrypha)
Offline
My idea would be to have wire mesh tires, made out of a special alloy that won't become brittle at extremely low temperatures. But I hope they don't forget to bring a small bulldozer, as that will be essential for clearing paths free of rocks and boulders, etc, not to mention a whole host of other uses.
For local travel (less than 5 km from the base), I would think that ATV-type vehicles would be ideal...they would be small, easy to use and have the ability to go almost anywhere, and hopefully easy to repair should they break down.
B
Offline
I know the U.S. Navy has operated C-130 aircraft in Antarctica when temperatures have been as low as -60 F and the only problem they had with their tires was that they would freeze to the ice at times.
Offline
Thanks, Cindy!
I knew we'd visited this subject somewhere.
Anyhow, I suppose research into engineering in almost cryogenic conditions will form part of the initiative President Bush has launched. After all, we'll have even worse problems on the Moon if we want to drive around during the 340-hour-long lunar nights, when temperatures can plunge to -180 deg.C !!
And then the temperatures can reach +130 deg.C in the middle of the 340-hour-long day!
Temperature tolerance demands placed on machinery at the new Moon base will make Mars look positively temperate by comparison.
The word 'aerobics' came about when the gym instructors got together and said: If we're going to charge $10 an hour, we can't call it Jumping Up and Down. - Rita Rudner
Offline
I have a real problem with so-called "temperature" in the vacuum of space. It seems to me, we could simulate whatever ambient temperature range we wished on Moon, simply by burrowing into the regolith, covering it over and fitting-out a huge laboratory for Martian day and night controlled conditions, including Mars-gee centrifuges for biological work. I know, I know: Moon nights will limit exposure durations to solar radiation, but since those effects are cumulative even that shouldn't present more than an inconvenience. As for zero-gee work, low Moon orbit would be relatively easy to attain and monitor from said lab.
Offline
Having recently worked on design of farm machinery going over just this question of tracks versus wheels, I'd definitely say go with wheels!
Among other things, tracks are out unless manufactured in place because of weight. Tracks are quite complicated and have lots of things that can go wrong. They have few advantages over wheels, except for their average PSI value which can be extremely low. They are used in some farm machinery, and for certain types of heavy equipment because of that.
Tracks are terrible on energy efficiency. It requires a lot of power just to turn the tracks around their capstans.
Did a back of the envelope cut at whether or not a bike would get bogged down on Mars. Basically, the low gravity greatly improves wheels for use even in environments that would be difficult on Earth.
Facts do not cease to exist because they are ignored. - Aldous Huxley
Offline
My idea would be to have wire mesh tires, made out of a special alloy that won't become brittle at extremely low temperatures.
*Not that tires are usually at the forefront of my consciousness (because they certainly are not, ha ha)...but I'm having difficulty visualizing this. Byron, do you mean tires made (entirely) of woven mesh? Or something along that line?
Do you have a link to a pic/image? Again, I'm trying to visualize this.
--Cindy
We all know [i]those[/i] Venusians: Doing their hair in shock waves, smoking electrical coronas, wearing Van Allen belts and resting their tiny elbows on a Geiger counter...
--John Sladek (The New Apocrypha)
Offline
My idea would be to have wire mesh tires, made out of a special alloy that won't become brittle at extremely low temperatures.
*Not that tires are usually at the forefront of my consciousness (because they certainly are not, ha ha)...but I'm having difficulty visualizing this. Byron, do you mean tires made (entirely) of woven mesh? Or something along that line?
Do you have a link to a pic/image? Again, I'm trying to visualize this.
--Cindy
Yes, I envision tires on Martian rovers to be made out of some sort of woven mesh, probably some kind of polymer fiber that's super-lightweight and able to withstand the frigid temps. IIRC, the lunar rover tires were made of a wire mesh material; in Mars' lower temperatures, you'd have to have something that wouldn't become brittle and can hold up under abusive conditions, etc.
Wish I had a link to show you, I'll poke around and see if I can find anything on this...
B
Offline
My idea would be to have wire mesh tires, made out of a special alloy that won't become brittle at extremely low temperatures.
*Not that tires are usually at the forefront of my consciousness (because they certainly are not, ha ha)...but I'm having difficulty visualizing this. Byron, do you mean tires made (entirely) of woven mesh? Or something along that line?
Do you have a link to a pic/image? Again, I'm trying to visualize this.
--Cindy
Yes, I envision tires on Martian rovers to be made out of some sort of woven mesh, probably some kind of polymer fiber that's super-lightweight and able to withstand the frigid temps. IIRC, the lunar rover tires were made of a wire mesh material; in Mars' lower temperatures, you'd have to have something that wouldn't become brittle and can hold up under abusive conditions, etc.
Wish I had a link to show you, I'll poke around and see if I can find anything on this...
B
*Well, this might sound really strange...but up north some folks put what my father called a "headbolt heater" near the starters of their vehicles' engines. They provided enough warmth to help start the engine more easily on very cold mornings (how well I remember that almost dead- and painful-sounding rrrrr...rrrrrr...rrrrrr....rrrrrr of trying to get it started; and then trying to be careful not to flood the starter, AGH!).
Could small heating units be tucked inside the tires, to keep them from getting too cold and thereby brittle (if and when they are "out and about" and not possibly resting in a heated shelter)? Metal conducts heat, too.
Why I am discussing tires anyway?
--Cindy
We all know [i]those[/i] Venusians: Doing their hair in shock waves, smoking electrical coronas, wearing Van Allen belts and resting their tiny elbows on a Geiger counter...
--John Sladek (The New Apocrypha)
Offline
Could small heating units be tucked inside the tires, to keep them from getting too cold and thereby brittle (if and when they are "out and about" and not possibly resting in a heated shelter)? Metal conducts heat, too.
I don't see why that wouldn't work...you would just have to dedicate extra power to do that from the engine, etc.
Why I am discussing tires anyway?
Because tires are cool!...lol
B
Offline