Bikes

JoshNH4H · 2012-03-20 12:26:55

Bicycles find a lot of use on Earth for short to mid range transportation. Given that the more car-like forms of transport are likely to be quite slow by our standards, I think that bikes could definitely find use on Mars. They would be less massive because the lower gravity reduces mechanical loading, and lighter on top of that because the lower gravity makes them weigh less. Steel should be a perfectly good construction material.

The potential difficulties as I see them are that spacesuits (Even the mechanical counterpressure variety) reduce a person's range of motion. Further, the lower gravity means that it will be easier to balance but harder to accelerate or brake. Within the colony it will probably be easier to walk the tunnels which will certainly be there for that purpose. I would expect bikes to be most useful for anything outside the colony but still within 25-30 km.

Thoughts?

GW Johnson · 2012-03-21 13:17:39

Given a supple MCP suit, I don't see why not. Just use fat balloon tires that are very tough to resist sharp rock puncture. Pressure can be quite low, just 3-6 times local atmospheric. Won't be easy riding in rocky dirt, but the fat tires make it a lot better. The fatter the better.

If they go with the gas balloon suits, no way. Need at least a tricycle, but a quadricycle is more stable. Trouble is, the more wheels, the more drag in dirt (it's also plowing forces, not just rolling friction). Puts you into needing a powered vehicle very quickly. But if you fall over, it's likely you will puncture the suit.

Suit puncture or tear is not much of a problem with MCP, especially if you have a vacuum-rated duct tape.

GW

John Creighton · 2012-03-21 18:59:48

All cool ideas, of course if the roads are good, or even better indoors, then bikes will be a win.

JoshNH4H · 2012-03-21 23:06:43

GW- I like your analysis of the matter. Given that acceleration need not (and in reality probably can not) be too quick, the bike probably doesn't need multiple gears. It can be simple and extremely light.

Even from the first mission, bikes could be very useful, as GW kind of obliquely referenced. The electric Lunar Roving Vehicle traveled up to 7.6 km from the landing site. If we get Mechanical Counterpressure suits that are as capable as they seem to have the capacity to be, I think we might see one day trips as far as 25 km from the landing site, just with bikes. (My math looks like this: Say up to 6 hours outside with up to one hour each way for transport. 25 km is 15.5 miles. That's a slow to moderate speed bike ride; and the lack of air and lower gravity on Mars may help to make up for the lack of paved roads and restrictions of an MCP suit.

Glandu · 2012-03-22 07:44:54

Do we have experience about high-effort management in space suits? I mean, once on a bicycle, one could push itself strong, with a lot of sweat & breath. I ask, as I have no clue. While working on ISS does not seem simple, the difficulty seems not to be physical effort. On Mars, il will be(biking, shoveling.....)

JoshNH4H · 2012-03-22 09:42:24

I don't believe that we have much experience with doing tasks that involve large amounts of effort or wide ranges of motion in space suits. Riding a bike or digging would probably be impossible in space suits right now.

On the other hand, as I mentioned above the bathing suits which led to many swimming records being broken and were then banned by the IOC are not all that different from an MCP suit. It is very clear that one can do difficult physical tasks in one of those. I can't find what kind of pressure the so-called "supersuits" put on a person to get a better idea of how close an analog they are.

GW Johnson · 2012-03-22 10:11:12

Practicality of a supple MCP suit? Yep. We already know it works.

Look at the 1969-vintage video of Paul Webb's elastic spacesuit tests way back then. The test subject was riding a bicycle ergonometer (at high effort level) for an extended period of time in an MCP rig, in a vacuum tank, at a simulated 87,000 feet (way above the "vacuum death point" for an unprotected human). He was sweating right through the MCP garment into vacuum, so he needed no cooling system other than his own biological one.

Webb did that with a breathing helmet and tidal volume bag, a bag restraint jacket, pure O2 at 190 mm Hg total (absolute) pressure, and a garment made of 6 layers of the then-new pantyhose material. The whole rig, including a liquid O2 supply, weighted 85 pounds total. Most of that was the helmet and O2 backpack.

Yeah, we can do this. We could have done it years ago. We could have done it decades ago.

GW

GW Johnson · 2012-03-22 10:17:02

Josh:

The MIT design is being forced to achieve a design target of 1/3 atm compression. They cannot meet that goal yet.

But they could easily meet Paul Webb's 190 mm Hg level.

The 1/3 atm goal (about 253 mm) is unrealistic given the materials we have, and further, it is unnecessary, given what is actually needed for life support (actually a bit less even than Webb's 190 mm, you only really need somewhere between 152-190 mm.)

GW

louis · 2012-03-22 17:17:33

GW Johnson wrote:

Given a supple MCP suit, I don't see why not. Just use fat balloon tires that are very tough to resist sharp rock puncture. Pressure can be quite low, just 3-6 times local atmospheric. Won't be easy riding in rocky dirt, but the fat tires make it a lot better. The fatter the better.
If they go with the gas balloon suits, no way. Need at least a tricycle, but a quadricycle is more stable. Trouble is, the more wheels, the more drag in dirt (it's also plowing forces, not just rolling friction). Puts you into needing a powered vehicle very quickly. But if you fall over, it's likely you will puncture the suit.
Suit puncture or tear is not much of a problem with MCP, especially if you have a vacuum-rated duct tape.
GW

I used to have "aero bar" tyres on my bike (a tyre with lot of air chambers inside). A fairly hard ride but totally puncture free - I am sure you could improve on that. I did suggest some years ago that electric bikes would be effective for local exploration. However, as Musk's technology has been proved and his cost projections have come down so far, I feel a small pressurised rover is probably worth taking along - it could double as a digger.

GW Johnson · 2012-03-23 18:02:59

I think I'd take the bikes and a big rover with a drill rig on it, pressurized or not. But I'd go with MCP suits, either way.

I'd completely divorce the vacuum protection from all the thermal and mechanical protection. The MCP rig is just vacuum-protective underwear plus a gas breather helmet. You wear then ordinary coveralls, ordinary hiking boots, ordinary leather work gloves, an ordinary wide-brimmed hat (on top of the helmet), or whatever is required. Doff what you don't need, whenever circumstances warrant.

With an MCP suit made of separate pieces (one-piece union suits make little sense to me since they hold no gas pressure), if dirt temperatures are between around -10C to 45 C, you can doff the work gloves, and the compression gloves, and thus handle dirt and rocks absolutely bare-handed on Mars (or in deep space) for up to about 10+ minutes at a time. That limit requires you re-don the compression gloves before swelling (tissue edema) sets in. The old experiments seemed to show significant pain and swelling in hands, starting around 20 minutes of exposure to vacuum.

Can you imagine being able to do fine electrical, plumbing, or mechanical assembly work in LEO with a suit like that? All you need is an unpressurized bay inside a an enclosure, with enough lighting power to bring the workpieces up to a range where you can touch them barehanded without frostbite or burns (-10 to 45 C).

Wow!

GW

Void · 2012-03-24 10:51:20

I like the idea that you can expose a hand, but I am wondering if a compromise could be used to give some of the benefits of being bearhanded, while, risking less a repetive type injury. In other words, I am thinking that repeatedly exposing hands to vacuum has unknown consequences, and I fear a accumulation of injury, and I think that a modified scheme might help.

Since we are generally "Handed", right or left, what if a right handed person, kept the glove on the left hand, using it for gripping only, and what if the right hand glove had open finger tips? I think that the finger tips are the most important tactile feature of the hand. What if in addition the right hand had a second outer glove you could pull over the fingertips from time to time. It could be a counterpressure glove, but it might be easier to slide a pressurized container over that hand with the exposed fingertips to rest the fingertips. Either an Apollo glove, or even a bit funny, a "Captain Hook" type prostesis.

The "Captain Hook" device would be a little canister your right hand could fit into with some type of sealing method. Eather a metal flange scheme, or a torroidal sphincter at the wrist. The canister would be pressurized by a device to compress Martian air into the right hand canister. (You seem to have this person working in a workshop, so a little air compressor is not that far off base). Then inside of the right hand canister would be a mechanical device which would allow the right hand to still do work squeezing the device to actuate a mechanical grip on the front of the canister, much like a person who has a prostesis can.

So in Mode 1: the person would have a left hand fully gloved, and a right hand partially gloved so that they could do tasks where the sense of touch and fingernails might matter. In Mode 2: They would rest their dominant hand inside of the pressurizable canister, but still be able to use the dominant hand to grip things using a prostesis double hook type device.

A modification of this would be to have one finger and thumb exposed, and to keep the other fingers which are mostly for power anyway protected by a partial glove.

Last edited by Void (2012-03-24 12:32:16)

GW Johnson · 2012-03-25 09:56:27

Those are all good ideas.

Actually, doffing and donning a compression glove in a multipiece MCP rig is not all that hard. It's like donning thin tight rubber gloves, then pulling a zipper up the back of your glove to increase the compression.

For most purposes, there would be little need to doff the compression gloves. These are about as supple as wearing thin tight rubber gloves down here. But, if I was trying to install a bunch of tiny machine screws with a dinky little screwdriver, or tap a drilled hole down in the 1/16 inch range or smaller, I might have to doff the gloves, given safe handling temperatures.

GW

louis · 2012-03-30 17:00:08

GW Johnson wrote:

I think I'd take the bikes and a big rover with a drill rig on it, pressurized or not. But I'd go with MCP suits, either way.
I'd completely divorce the vacuum protection from all the thermal and mechanical protection. The MCP rig is just vacuum-protective underwear plus a gas breather helmet. You wear then ordinary coveralls, ordinary hiking boots, ordinary leather work gloves, an ordinary wide-brimmed hat (on top of the helmet), or whatever is required. Doff what you don't need, whenever circumstances warrant.
With an MCP suit made of separate pieces (one-piece union suits make little sense to me since they hold no gas pressure), if dirt temperatures are between around -10C to 45 C, you can doff the work gloves, and the compression gloves, and thus handle dirt and rocks absolutely bare-handed on Mars (or in deep space) for up to about 10+ minutes at a time. That limit requires you re-don the compression gloves before swelling (tissue edema) sets in. The old experiments seemed to show significant pain and swelling in hands, starting around 20 minutes of exposure to vacuum.
Can you imagine being able to do fine electrical, plumbing, or mechanical assembly work in LEO with a suit like that? All you need is an unpressurized bay inside a an enclosure, with enough lighting power to bring the workpieces up to a range where you can touch them barehanded without frostbite or burns (-10 to 45 C).
Wow!
GW

Great observations.

I wonder whether we could develop a kind of fine filament underglove to warm the hand and fingers, but to allow direct contact between the ends of the fingers and the environment. I am thinking it would look a bit like fishnet material.

I think this touch experience will be one of the most wonderful emotional moments for the first colonists, when they have that hands on experience.

quasar777 · 2012-04-12 08:56:48

Has anyone heard of the handcarts used on the lunar surface?

GW Johnson · 2012-04-13 11:51:01

Sure. They're a good idea too.

GW

quasar777 · 2012-09-23 12:33:51

By the way, we've had ongoing thread here. "Bikes on mars, don't laugh". Has evry1 here read the old article about lunar bikes? & yeh i know mars is different than the moon.

JCO · 2015-01-27 18:10:15

I think bicycles may not be ideal for transportation on Mars but I can definitely see human powered vehicles dominating the landscape. With the exception of very heavy equipment. I road a bike from Vermont to California so I do know a bit about traveling by bike. It was a lot of fun but it had some hare limitation that 3 or 4 wheeled vehicles do not have. A trike designed for mars could actually have a pressurized compartment and still be fairly easy for the driver to power themselves. A human powered vehicle with the same mass as a motorcycle on Mars would accelerated slowly but once moving would require no more effort than a bike to keep it moving. Using human powered vehicles would also likely be a great help in combatting muscle and bone degeneration as it could be easy to get a good deal of physical activity as a normal part of daily life.

SpaceNut · 2020-08-24 13:12:51

Being an out of shape 62 year old needing to get the daily supplies 2 miles one way from home has given a new meaning to how hard it would be to use a 2 wheeled unit on the rough land of mars. It's going to be some time before man can use them as safety is first for a rider that might have a suit failure.

tahanson43206 · 2020-08-24 19:08:49

For SpaceNut re #18 and Craig's List

After posting the image of a recumbent bike in Bedford, I decided to push on through the entire set of 800+ images. There were two more recumbents (worth considering) but they were a ** lot ** more than the one I first found.

(th)

SpaceNut · 2020-08-24 19:16:59

Thanks I did see it....

Mars_B4_Moon · 2022-08-06 07:33:17

Porsche drives deeper into electric bike market, creates two new e-bike companies

https://electrek.co/2022/08/02/porsche- … companies/

SpaceNut · 2022-08-06 07:52:26

key is this is modern built bicycle with an electric motor and throttle control....

The Porsche eBike Sport is for the street and the eBike Cross is for rougher terrain. The bikes cost $10,700 and $8,549, respectively.

Seems if you are rich no problem as this is 10 times too expensive for what it is....

tahanson43206 · 2022-08-06 07:59:56

For Mars_B4_Moon re #21 - thanks for finding and showing this new development

For SpaceNut .... The price looks about right to me ... 99% of the price is the company that stands behind the product.

No other manufacturer you might consider will provide you with any support beyond the obligatory 30 days (if you are lucky).

Plus, the resale value will match the starting price, or it might even increase if you hold the product long enough.

(th)

GW Johnson · 2022-08-06 10:42:12

Remember that 99% of Mars's surface resembles nothing so much as "soft fine sand" here on Earth, maybe with some rocks dispersed in it, and maybe not. It varies as the winds move the dunes around. That stuff has a max safe bearing pressure of 0.10 MPa (about 1 US ton per square foot), and its failure pressure (at which something stabs in deep, below the surface) is in the vicinity of 0.25 to 0.30 MPa.

That is just not very much pressure. Not much at all, as a matter of fact. To "calibrate" that for you, try walking on a dry wind-blown sand dune. The pressure under your shoes is demonstrably too high. It's above 0.3 MPa. It's not a static load, either (which would be around 0.12 to 0.15 MPa). It's dynamic as you impact first one foot and then the other, plus the push-off effects. Try multiplying by factor 4 or 5 for the transient dynamics (for 0.5 to 0.6 MPa). See why your feet sink in on the sand dune? On Mars that would be around .19 to .23 MPa, which is getting very marginal, and is not yet factored up by another factor of 2+, for a gas balloon suit and backpack.

Any bike on Mars will require very fat balloon tires, the lower gravity there notwithstanding. Such a bike cannot (and will not) look like any bikes here, manual or powered.

And you WILL NOT (!!!) ride any kind of bike on Mars while wearing the kind of gas balloon space suits we are currently saddled with. The only possibility for bike riding on Mars would be a development of MCP technology, and even that approached more the way Paul Webb did it, than the way Dava Newman did it.

The total Mars weight of human, suit, and bike has to be supported by the contact patches underneath the two bike tires. Those contact patches will have to be very large indeed. 200 lb man + bike, 200 lb suit = 400 lb Earth, ~ 150 lb on Mars. To achieve the safe bearing pressure 0.1 MPA = 2000 lb/sq.ft, the total contact patch area is some 0.076 sq.ft = 10.9 sq.in. that's about 5.5 sq.in on each tire. That contact patch would be about 2.3 inch x 2.3 inch if square. That's 6 x 6 cm.

See what I mean? It's doable, but it will not look like any bike here. And you really need the far lighter-weight MCP suit and backpack.

GW

Last edited by GW Johnson (2022-08-06 10:58:20)

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#1 2012-03-20 12:26:55

Bikes

#2 2012-03-21 13:17:39

Re: Bikes

#3 2012-03-21 18:59:48

Re: Bikes

#4 2012-03-21 23:06:43

Re: Bikes

#5 2012-03-22 07:44:54

Re: Bikes

#6 2012-03-22 09:42:24

Re: Bikes

#7 2012-03-22 10:11:12

Re: Bikes

#8 2012-03-22 10:17:02

Re: Bikes

#9 2012-03-22 17:17:33

Re: Bikes

#10 2012-03-23 18:02:59

Re: Bikes

#11 2012-03-24 10:51:20

Re: Bikes

#12 2012-03-25 09:56:27

Re: Bikes

#13 2012-03-30 17:00:08

Re: Bikes

#14 2012-04-12 08:56:48

Re: Bikes

#15 2012-04-13 11:51:01

Re: Bikes

#16 2012-09-23 12:33:51

Re: Bikes

#17 2015-01-27 18:10:15

Re: Bikes

#18 2020-08-24 13:12:51

Re: Bikes

#19 2020-08-24 19:08:49

Re: Bikes

#20 2020-08-24 19:16:59

Re: Bikes

#21 2022-08-06 07:33:17

Re: Bikes

#22 2022-08-06 07:52:26

Re: Bikes

#23 2022-08-06 07:59:56

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#24 2022-08-06 10:42:12

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