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#26 2018-10-03 03:57:22

elderflower
Member
Registered: 2016-06-19
Posts: 1,087

Re: Quadracycles

I would expect something that looks more like an earth wet suit than the Michelin man and I would expect electric power with human pedalling only for boost or when subject to unscheduled discharge of batteries.

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#27 2018-10-03 21:13:54

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 15,054

Re: Quadracycles

For mars tracks just might be the choice to design with rather than wheels.
Some sort of transmission and generator setup to allow for direct drive or generator mode for the electric hybrid would also work well on earth as well.

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#28 2019-03-03 13:28:11

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 15,054

Re: Quadracycles

We know that 1 and 2 wheeled pedal power unless fully enclosed in a dome but hybrids might be the way to go with multiple power sources to make there use possible in a mobile archetecture format of exploring mars.

Single pages walk you through the build
http://www.spiller.si/pedalcar/en/

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#29 2019-03-03 16:27:16

louis
Member
From: UK
Registered: 2008-03-24
Posts: 4,565

Re: Quadracycles

My view of this subject is influenced by how long it actually takes to get into a spacesuit. I think something like the lunar suit was four hours, presumably with all the pre-EVA checks.  Even if we can get it down to an hour with an MCS I still think that makes it impractical (you have to get the damned suit off eventually, remember). I think  all transport systems will be pressurised.  EVAs in spacesuits will be strictly PR exercises, or might be necessary for really close up work by geologists.


Let's Go to Mars...Google on: Fast Track to Mars blogspot.com

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#30 2019-03-04 08:19:17

elderflower
Member
Registered: 2016-06-19
Posts: 1,087

Re: Quadracycles

Louis, the fastest entry into a suit will be needed when personnel need to evacuate somewhere in an emergency. If there is a fire in the hab it might need to be vented to allow the fire to be controlled, for instance. Also when a rescue is needed, and it is bound to happen sometime. For these circumstances we need some kind of suit that can be donned in a few minutes, not one or more hours.

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#31 2019-03-04 08:55:44

kbd512
Moderator
Registered: 2015-01-02
Posts: 2,717

Re: Quadracycles

In case of a fire, you need to put your suit on in 60 seconds or less.  You can't be on a hose team in the Navy if you can't get all of your firefighting equipment on in less than 60 seconds, for example.  I assume that any habitat module would be equipped with Halon.  You have around 15 seconds to make it to the door once Halon has been activated in a main space, which means every habitat module must be sub-divided into at least two compartments and personnel must wear emergency oxygen bottles on their person.  Regular drills are also required to condition responses to emergency events.

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#32 2019-03-04 16:16:46

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 15,054

Re: Quadracycles

That is an issue, So if one can grab a gas mask with oxygen sort of like a divers, then one could simply flood a chamber with nitrogen gas to extinguish any fire. The vent to a processing unit the chambers atmosphere to be reclaimed and restore once flames are out.

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#33 2019-03-05 03:40:17

elderflower
Member
Registered: 2016-06-19
Posts: 1,087

Re: Quadracycles

If there is a fire you probably will want to discard the atmosphere of the affected compartments as they will contain nasty products of combustion as well as extinguishing agent. Better to vent it and make it up again when the fire is completely dowsed and the affected materials have been removed.

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#34 2019-03-05 11:15:44

tahanson43206
Member
Registered: 2018-04-27
Posts: 575

Re: Quadracycles

For elderflower and others who may be interested ...

The experience of submarine crews seems close to what underground Mars dwellers will have.  kdb512 has spoken to fire suppression aboard surface vessels.

My reaction to the psychological state of readiness kbd512 describes is (a) recognition with an army bias (b) hopelessness for a "normal" population.

I am guessing here, (and hoping for comments by those who know), but perhaps submarines are designed to address various emergency situations.

From reading over time, I've gained the impression that training aboard modern submarines is constant, with crew expected to maintain existing skills while developing new ones with every work shift.

On Mars, (or the Moon, for that matter) there would need to be designs for habitat and work areas which anticipate known risks, and try to anticipate unknown risks as much as possible.  Training for emergency response could be maintained on/in a military habitat or work area, and a corporation that wants to be around for a while would undertake similar efforts, but (I am guessing again) the average person living in a personal habitat is likely to experience fading capability over time.

Because of that near certainty, habitat systems need to be designed to expect poor human response, and to avoid risks as much as possible.

(th)

elderflower wrote:

If there is a fire you probably will want to discard the atmosphere of the affected compartments as they will contain nasty products of combustion as well as extinguishing agent. Better to vent it and make it up again when the fire is completely dowsed and the affected materials have been removed.

Last edited by tahanson43206 (2019-03-05 11:20:13)

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#35 2019-03-05 14:20:48

kbd512
Moderator
Registered: 2015-01-02
Posts: 2,717

Re: Quadracycles

tahanson43206,

I'm simply relaying the reality of fire in a confined space from which there is no realistic possibility of escape.  You can train almost anyone to do just about anything, but that takes time and money.  If you want your people to survive, then you're going to train them.  If you insist on putting high voltage equipment capable of arcing and sparking inside a pressurized environment, then those people must have training to immediately respond to life threatening events such as fires.

Fire Protection Aboard the Space Station | CSA Science Video

What is Halon and How Does it Work?

Why Halon?  It doesn't displace enough O2 to asphyxiate people.  You can still breathe after a Halon release.  Nitrogen, Argon, CO2, etc will all asphyxiate people in the quantities required to adequately suppress a significant fire.  The only real problem with Halon was its tendency to freeze things and people in the quantities used inside main spaces to suppress fuel oil fires.  There are no fuel oils used in space, so very little will be required.  Envirowacko religion aside, it's generally the best option inside an aircraft or spacecraft or other places filled with electronics and humans.

What Halon Alternatives Are There?

As a result of the ban on Halon and the issues with asphyxiation from the CO2 extinguishers, these new water-based extinguishers are being sent:

Mines-developed fire extinguishers headed to Space Station

Water will invariably destroy the electronics, but if it keeps the envirowackos happy, then I'm all for it.  Who needs electronics to run the life support systems, anyway?

Maybe newer electronics that are corrosion resistant will be used.  If we insist on using water vapor foggers, then they'll have to be.  No resupply is coming for another 26 months or so.

Pressurized environments with electrical power generation equipment (the electric generator for a pedal-powered vehicle, for example) or other high voltage electronics located inside it needs careful consideration given to the possibility of fire.  There's a reason that the batteries on the ISS are located outside the station.  It's better to not have to deal with problems like that, which you already noted.

Finally, aboard military ships and aircraft, the constant training is a constant reminder of the environment you're living and working in.  Thankfully, all the fires I had to extinguish aboard ships were small and a result of welding activities for repairs igniting combustibles like insulation, rather than electrical short-circuits or fuel oil fires.  The handheld CO2 bottles were sufficient.  Most of the training you receive involves kerosene and paper / fabric combustibles.  Flight deck crews receive additional training in combustible liquids and metal fires.  The takeaway should be that you need regular training, not that a civilian can't easily learn to do all of this.  It's not rocket science.

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#36 2019-03-05 14:23:19

elderflower
Member
Registered: 2016-06-19
Posts: 1,087

Re: Quadracycles

You are right to a large extent, tahanson, however on Mars people may escape a fire or similar emergency by going outside with a suit on, provided there is redundancy in habitations and the means to transfer themselves. Not an option in a submerged boat and limited in a surfaced one. It also strikes me that a large part of the population are going to be scientists selected for their performance in their discipline and not necessarily the kind of person who would gravitate to the submarine service.

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#37 2019-03-05 15:58:17

tahanson43206
Member
Registered: 2018-04-27
Posts: 575

Re: Quadracycles

For elderflower ...

Thank you for your pointer to a (possible) discussion of underground habitat design to facilitate safety of residents.

For SpaceNut ... please show (me at least) where you want that discussion to occur.  I would propose building on elderflower's observation, and the contributions of others in past discussions, to arrive at a design that would stand up to rigorous review by (among others: kbd512 and GW Johnson).

I believe others have already suggested isolating dangerous manufacturing facilities from human (or animal/plant) facilities.  One way to do that would be to insure that access to dangerous facilities is ONLY via surface entry, and NOT via tunnels.

This policy would encourage use of remote control robotic equipment which would be directed in (relative) safety from human habitat areas.

For kbd512 ...

Thank you for the additional perspective on training relative to safety in dangerous settings.  I think your observations apply to many settings on Earth, and we still have an amazing number of fatalities caused by taking excessive risks, unbelievable ignorance of risk, or events that overwhelm even the most prepared.

Your quote below provides an opportunity to bring the discussion back to Quadracycles, and specifically to my (tentative) proposal of a shirtsleeve cabin for a very light weight human powered vehicle for Mars (or potentially for the Moon, although I am skeptical it can be stretched that far).

Your observation that if a generator is located inside the cabin, then there is a risk of arcing and thus ignition of combustible materials inside the cabin.

A first order suggestion (one which may not hold up to review) is to design the airtight structure so that the moving magnet is inside the enclosure with the operator, and the generator coils outside, along with batteries, electronics and everything else that might contribute to fire danger.

(th)

kbd512 wrote:

tahanson43206,

Pressurized environments with electrical power generation equipment (the electric generator for a pedal-powered vehicle, for example) or other high voltage electronics located inside it needs careful consideration given to the possibility of fire.  There's a reason that the batteries on the ISS are located outside the station.  It's better to not have to deal with problems like that, which you already noted.

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#38 2019-03-05 17:57:06

kbd512
Moderator
Registered: 2015-01-02
Posts: 2,717

Re: Quadracycles

tahanson43206,

The Martian environment is simply not amenable to human life, but that doesn't mean we can't work around the obvious problems.

I'm concerned about a generator that would invariably require lubrication to run (all practical motor-generators are lubricated with various greases), some of which are flammable, and the arcing that is inherent in the common commutated electric generators found in sporting bikes / trikes / quads that store electrical power to provide a battery boost / assist up a hill.

Could a completely sealed motor-generator that uses dry film or other surface treatment lubricants and electronically-controlled BLDC motor-generators be used?

Yes, but this would be a significant engineering and testing effort unto itself.  The electronics require hardening and shielding from the radiation environment to assure proper function, especially if the vehicle is ordinarily to be left outside, non-flammable wiring insulation, and special connectors that contend with thermal expansion and vibration / shock while maintaining solid electrical connection.

We already have compressed air and electric motorcycles that have been exhaustively tested to assure reliability and durability in off-road conditions, so why not use those?

I think pedal power is a non-starter for Mars until such time as we have space suit technology beyond what we have today.  The ISS space suits weigh 485 pounds.  The astronaut is another 150 pounds.  Add at least 80 pounds worth of vehicle to carry that.

The Utah Custom Fat Cat quad, something that looks like a real off-road machine, weighs 80 pounds.  That's 272 pounds (in Mars gravity) worth of rider and vehicle to push up a hill in the absolute smallest shirtsleeve environment available, which is a standard ISS space suit.  The Fat Cat is Aluminum, so perhaps composites could help save a little weight, but the weight savings won't be too dramatic.  Fat Cat also needs an upgraded suspension system to contend with debris fields.

UTCustom Catrike Fat Cat-4 Quad

The vehicle has to be light enough for a single human to move through very rough terrain and protective enough to contend with the inevitable accidents.  I don't see that happening if we're using standard space suit design or a shirtsleeve cabin environment.  It's just too heavy.

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#39 2019-03-05 19:21:57

tahanson43206
Member
Registered: 2018-04-27
Posts: 575

Re: Quadracycles

For kbd512 ...re #38

First, thanks for the link to the Fat Cat-4 Quad!  Impressive vehicle, and the comments of happy buyers added to the impact.

Second, thanks for the thoughtful analysis of risks that might face the operator of an enclosed cabin pedal powered vehicle.

I confess to being puzzled by your concern about arcing inside a passenger compartment with an atmosphere of 20% oxygen and 80% nitrogen (or other inert gas).  A person caught away from base with exhausted electrical power and the need to traverse several kilometers to reach safety would be (I would think) more concerned about oxygen holding out than the risk of arcing in a well designed generator.

In your scenario, for the arcing to be a problem, there would have to be something combustible for the arc to ignite.  What would that be?

Finally, rough terrain would be a challenge, no doubt, but why is it necessary to assume roads would not be bulldozed (or otherwise prepared) as a first order of business for a settlement?

I am assuming pedal power as a backup for electric motors, or air pistons, or whatever other traditional motive system is provided.

Beyond the emergency backup capability, it seems to me that an enclosed cabin vehicle for movement between airlocks on the surface might be pedal powered as a primary mode of operation, with electric power a welcome substitute when available.

Thanks again for that Quad link!

Here is a link to an image of a small helicopter with a plastic bubble cockpit.  The pedal vehicle I am visualizing would (or could) look like this:

https://res.cloudinary.com/redballoon/c … kpiqbrorhg

Using guide from SpaceNut: Success: Left bracket img Right bracket URL of Image not in quotes Left bracket slash img Right bracket

jfj3dantphkpiqbrorhg

(th)

Last edited by tahanson43206 (2019-03-05 19:50:09)

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#40 2019-03-05 20:38:05

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 15,054

Re: Quadracycles

For those hung up on fire this is what the ISS has...

Overview of ISS US Fire Detection and Suppression System
https://ntrs.nasa.gov/archive/nasa/casi … 053429.pdf

Development of the International Space Station Fine Water Mist Portable Fire Extinguisher
https://ntrs.nasa.gov/archive/nasa/casi … 011664.pdf

Fire Prevention in Space
https://www.nasa.gov/missions/shuttle/f … ntion.html

Nice image of a dome window to drive from tahanson43206

Thanks for the Fat tire vehicle and as kbd512 starts to bring up for arcing which can occur with a brushed style contact and lubrications but we can make brushless designs for motors and generators with bearing that are self lubricating. Guarding from dust entry is the issue for lubricants.

Since man is not wearing a full space suit all the time we need good detection and safe haven pods with spare gear to allow for quick exit from a section that will be closed off for fire fighting that will come on automatically with alarms to tell you where it might be.

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#41 2019-03-06 05:42:11

elderflower
Member
Registered: 2016-06-19
Posts: 1,087

Re: Quadracycles

conventional lubricants (based on liquids or semisolids) will turn themselves into abrasive pastes with the addition of a little dust, but dry lubricants will work and are used on earth for equipment that will be exposed to possible dust pickup. Typically Fluorinated hydrocarbons, Molybdenum disulphide and graphite can be used.
Dry gas lubricated bearings are available but they require great attention to excluding contaminants due to their very small clearances.
Also Magnetic bearings can be used, but they will pick up any iron containing dust and retain it so they may be worse on Mars (which is covered in rust) than the other two technologies.
Recirculating liquid bearings can be used, with means to remove solid contaminants (centrifuges and very fine filters for example). Sealing these is a problem as the slightest weep will build up an abrasive paste. There are ways of doing this involving buffer gas, but the gas is lost continuously. They do have the advantage that the recirculating fluids can be used for heating or cooling as well as lubrication. There are other complications: these systems use a fair bit of power for their pumps, centrifuges, filter cleaning etc and involve quite a lot of other equipment items (pumps, heat exchangers, Breathers, reservoirs as well), and there are many potential failure points.
On the whole I would prefer the first option for use on Mars unless cooling is required and cannot be carried out with conduction and/or radiation.

Last edited by elderflower (2019-03-06 05:45:10)

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#42 2019-03-06 08:29:32

tahanson43206
Member
Registered: 2018-04-27
Posts: 575

Re: Quadracycles

For elderflower ...

Thank you for the thoughtful analysis quoted below.

To make it easier (for me at least) to find in future, I've added a lookup capability:

SearchTerm:Lubricants

NewMars forum may attract knowledgeable contributors over time, to complement the disciplines already in evidence here.

(th)

elderflower wrote:

conventional lubricants (based on liquids or semisolids) will turn themselves into abrasive pastes with the addition of a little dust, but dry lubricants will work and are used on earth for equipment that will be exposed to possible dust pickup. Typically Fluorinated hydrocarbons, Molybdenum disulphide and graphite can be used.
Dry gas lubricated bearings are available but they require great attention to excluding contaminants due to their very small clearances.
Also Magnetic bearings can be used, but they will pick up any iron containing dust and retain it so they may be worse on Mars (which is covered in rust) than the other two technologies.
Recirculating liquid bearings can be used, with means to remove solid contaminants (centrifuges and very fine filters for example). Sealing these is a problem as the slightest weep will build up an abrasive paste. There are ways of doing this involving buffer gas, but the gas is lost continuously. They do have the advantage that the recirculating fluids can be used for heating or cooling as well as lubrication. There are other complications: these systems use a fair bit of power for their pumps, centrifuges, filter cleaning etc and involve quite a lot of other equipment items (pumps, heat exchangers, Breathers, reservoirs as well), and there are many potential failure points.
On the whole I would prefer the first option for use on Mars unless cooling is required and cannot be carried out with conduction and/or radiation.

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#43 2019-03-06 08:39:53

kbd512
Moderator
Registered: 2015-01-02
Posts: 2,717

Re: Quadracycles

tahanson43206,

Let's just say that from past experiences, I'm a little paranoid about fire.  I take it you've never been trapped with a fire.  That's a good thing.  Being trapped inside a small compartment with a spark machine, combustible lubricants, and no ability to escape doesn't give me a warm fuzzy.  It's always the seemingly inconsequential things that turn out to be major problems.  You never think about them until they don't work.

As long as whomever designs this thing understands that virtually nothing used on Earth is suitable for Mars, there won't be any problems.  No petroleum products in the lubricants.  No flammable insulation on the wiring.  No composite parts that outgas and lose strength.  The rubber must be of a variety that doesn't fall below its glass transition temperature (yes there are actually rubber compounds developed by NASA that can handle moderately cryogenic temperatures).  Limited use of metals that create secondary particle showers from GCR.  Any electronics are rad hard.  If the tires are of the inflatable variety, then they need to be inflated with N2.  If it's not apparent yet, this off-road quad will be a completely custom one-off development effort despite the fact that the basic design.  The Fat Cat is easily a $10,000 machine with functionality and usability upgrades.  The design that ultimately goes to Mars will easily cost more than a good electric car.

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#44 2019-03-06 09:08:09

tahanson43206
Member
Registered: 2018-04-27
Posts: 575

Re: Quadracycles

For kbd512 re #43 ... thanks for expanding on the (helpful/useful) theme of risks to be addressed in design of a Personal Mobility Vehicle for Mars.

To try to add to the value of this thread for others (like me) who might find some of the design concerns to be daunting, I checked in with Wikipedia to try to gain a better understanding of the atmosphere on Mars, and learned (among other things) about the "Armstrong Limit". 

https://en.wikipedia.org/wiki/Atmosphere_of_Mars

The atmosphere of the planet Mars is composed mostly of carbon dioxide. The atmospheric pressure on the Martian surface averages 600 pascals (0.087 psi; 6.0 mbar), about 0.6% of Earth's mean sea level pressure of 101.3 kilopascals (14.69 psi; 1.013 bar). It ranges from a low of 30 pascals (0.0044 psi; 0.30 mbar) on Olympus Mons's peak to over 1,155 pascals (0.1675 psi; 11.55 mbar) in the depths of Hellas Planitia. This pressure is well below the Armstrong limit for the unprotected human body. Mars's atmospheric mass of 25 teratonnes compares to Earth's 5148 teratonnes; Mars has a scale height of 11.1 kilometres (6.9 mi)[2] versus Earth's 8.5 kilometres (5.3 mi).[3]

In a reasonable market place, there should (and most likely will) be vendors offering a variety of options for customers for personal mobility.

Suits of all kinds are likely to be on offer.  Some will certainly address the concern expressed by Louis recently, about it taking three hours to don a pressure suit. I think that time comes from experience on the ISS, where the suit must deal with pure vacuum.  The suits designed for Mars seem likely (to me at least) to resemble flight suits for high altitude pilots, with the addition of Scuba-like oxygen tanks.

In the field of Personal Mobility Vehicles, there will (most likely) be a wide range of offerings, from a pedal powered vehicle for a person in a suit, through the most sophisticated multi-passenger transporter.  In that spectrum I expect there will be small, lightweight vehicles which provide "normal" atmosphere for the operator thanks to a lightweight enclosure. 

Each purchaser (or renter) of one of these offerings will (no doubt) make risk vs reward assessments, based upon statistics compiled over time for each product.

My guess is that while the concerns expressed by kbd512 are serious and must be addressed, experience on Earth seems to suggest (to me at least) that over the past 100 years or so humans have come up against various challenges along these lines, and found ways to mitigate them.

In other words, if I were comparing the challenge of an emergency evacuation from an underground habitat using a suit, or a Personal Mobility Vehicle, I would be weighing many factors including fire risk, plus my strength and agility.  Another factor that will surely come into play is the presence of dependents who cannot be fitted with a suit for whatever reason.  In such situations, the availability of a cabin enclosed vehicle might prove attractive.

Something to add to the mix is the voltage of electrical systems.  Humans have a lot of experience with low voltage systems.

This isn't to say that low voltage systems are not dangerous.  It is simply to say that humans have a lot of experience with them.

(th)

Last edited by tahanson43206 (2019-03-06 10:42:56)

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#45 2019-03-06 10:40:18

kbd512
Moderator
Registered: 2015-01-02
Posts: 2,717

Re: Quadracycles

tahanson43206,

This could certainly be done.  I like the idea of a purely mechanical backup system to all the fancy electronics, which are absolutely fantastic until they stop working.  However, for an actual human-powered vehicle to provide a shirtsleeve environment for a single occupant, the mass of the vehicle and everything carried aboard would have to be rigorously controlled.  This would be a full-on interdisciplinary aerospace engineering project.

At the present time, I think available resources are better utilized to ensure the reliability of everything else required to go to/from Mars and live there.  After we get to Mars, design better spacesuits that are optimized for the Martian environment, establish a permanent base in a suitable location, and adequately characterize the local terrain, then a human-powered vehicle suitable for that location becomes a worthwhile technology pursuit and addition to a cargo manifest that includes competing items with higher priority (consumables, spare parts, etc).

I'm sure that something like this could be tested on the moon first, but there may be environmental peculiarities that don't apply on Mars and the gravity is less on the moon so vehicles that might be usable in the even lower gravity field of the moon may not work as well on Mars.  I like the idea and I think it's interesting from a mass / power reduction perspective for transportation, but it's not a priority.  Given sufficiently advanced space suit technology, a pedal-powered bike or quad would become far more practical.

We're just starting to develop mass manufacturing methods for the lightweight materials that could make a Mars-rated Fat Cat feasible.  I think things like buckypaper (optionally electrically conductive or insulating high strength fabric for seat covers), aerographene or aerographite (seat cushion material / helmets / pads), 3D Graphene / CNT "rebar" (CNT-reinforced Graphene) for bolts and screws and helmets (yes, there's actually a G/CNT "rebar" helmet that's been fabricated for testing, eventually intended for commercial sale if testing goes well), BNNT paper (GCR and SPE protection over vital areas such as the head / chest / groin), and CNT threats / yarns / fabrics (for composites) will greatly aid in the design of this and other lightweight vehicles.  However, fabrication must be fully industrialized and tested in practical applications first.

The military is extremely interested in this sort of technology.  Our special forces make extensive use of powered bikes and quads in Afghanistan to ambush the Taliban to beat them at their own game.  Most of the casualties come from ambush attacks on roads.  If you can stay off the roads and still be faster than someone on foot, far fewer people die.

Zero Motorcycles - Military

DARPA is actively working on development of silent electric bikes and quads for use overseas.  This is the sort of project for them to undertake since it benefits our military.

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#46 2019-03-06 12:42:37

tahanson43206
Member
Registered: 2018-04-27
Posts: 575

Re: Quadracycles

For kbd512 .... Awesome!

https://www.zeromotorcycles.com/fleet/military/

I wonder what "aggressive" foot pegs are! The ones shown as standard look pretty minimal to me.  The Romans (and many others) added blades to the wheels of chariots, in what advertising at the time might have called "aggressive".

You said a couple of things I'd like to highlight:

kbd512 wrote:

This would be a full-on interdisciplinary aerospace engineering project.

At the present time, I think available resources are better utilized to ensure the reliability of everything else required to go to/from Mars and live there.

The NewMars forum does not currently appear to be set up to do a project, let alone one as strenuous as needed for a Mars rated Fat Wheel Quad.

That's not what NewMars forum was set up to do, as I understand the history.

However, that limitation does not necessarily always need to stay in effect.

Your reference to "available resources" could be expanded a bit, if there is interest.

In the mean time, I'd like to offer a perspective ...

Present initiatives to reach out into near space remind me of expeditions of centuries past, which (often) represented the peak capability of the respective cultures.  Columbus, Magellan and the Chinese sea expeditions are just the tip of that particular iceberg of collective achievement.

But all those were dwarfed by the Invasion of Normandy, championed by Churchill and Roosevelt, and led by Eisenhower.

I am preferring to think of a Normandy scale settlement of Mars, much as I admire the achievements which are soon to come, at the Apollo scale.

My belief is that EVERY person who will become a business owner and service provider in a community on Mars is alive today.

A statistic was published recently, reporting that the planet Earth now has well over 2,000 billionaires.   The point I am trying to make is that the planet is wealthy enough to undertake a large scale development off planet, and there are signs (as I interpret the news) that more people than Musk and Bezos are thinking seriously of making even greater fortunes off planet.

It is my expectation that, like suppliers of goods during the California Gold Rush, suppliers of Mars certified Personal Mobility Vehicles will be in the forefront of entrepreneurs looking to establish and build businesses on Mars.

Surprise (to me) ... Wikipedia clarified that Levi Strauss did NOT sell jeans to miners, as I had thought.

Levi Strauss

Apparently that myth was started by an advertising campaign.

(th)

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#47 2019-03-06 13:20:49

kbd512
Moderator
Registered: 2015-01-02
Posts: 2,717

Re: Quadracycles

tahanson43206,

Space exploration is largely a special interest group within government and industry.  If it's useful for political purposes, then there are some who will be interested to use space to gain favor with their political base.  If not, those in power are typically disinterested in it because it does nothing to enhance their political standing.  The level of associated effort with our manned space program is about as much as the landings at Inchon during the Korean War.  All said and done, the number of people actually working on space exploration technologies may approach the total number of belligerents at Inchon, which was estimated to be about just below 50,000.  It wouldn't surprise me if the total global effort devoted to manned space exploration programs isn't much higher than that.  It's interesting from a scientific perspective and useful in terms of the spin-off technologies developed, but that's about as far as it goes.  We still haven't actually learned how to live and work in space for long periods of time.  Once we do that, then you'll see more interest.

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#48 2019-03-06 17:57:10

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 15,054

Re: Quadracycles

I believe that some of the analog sites are using ATV's for getting around on the exploration exercises; on going at the various sites.
This could be a nice blend of contest and use for any new crews to try as well.

1 limits of duration being used.
2 distance to traverse

of course other condition would need to be listed for the creation to test the practicle limits for men on mars

edit just another vehicle reference

https://www.motor1.com/news/75902/this- … dal-power/

Raht Racer charges a 9.2kWh lithium-ion battery which in turn drives a 19 horsepower electric hub motor in the rear wheel. able to achieve top speeds between 90 and 100 miles per hour, and can travel approximately 50 miles on a single charge

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#49 2019-03-07 21:42:53

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 15,054

Re: Quadracycles

Table: wheel size for speed to revolution
Rad ft     Cir ft    R/Mi    5mph    rpm    10mph    rpm    15mph      rpm
1.0         6.3    840    4,200/60=70    8,400/60=140    12,600/60=210   
1.5         9.4    560    2,800/60=46.7    5,600/60=93.3     8,400/60=140
2.0      12.6    420    2,100/60=35    4,200/60=70     6,300/60=105
2.5      15.7    336    1,680/60=28    3,360/60=56     5,040/60=84

Drive wheel motion which changes with the pedaling gear ratio. What is being done is a conversion of rpm and torque to give speed.

https://www.bicycling.com/bikes-gear/a2 … ike-motor/

https://support.electricscooterparts.co … 1000072733

https://sheldonbrown.com/twist.html

https://www.physicsforums.com/threads/c … le.677026/

http://courses.washington.edu/engr100/S … Torque.doc

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#50 2019-03-07 22:04:20

kbd512
Moderator
Registered: 2015-01-02
Posts: 2,717

Re: Quadracycles

SpaceNut,

Maybe we can find an astronaut who's built like "Ahhnuld" who can pedal his Fat Cat up a decent hill.  Let's partner him up with a 95 pound woman.  Can she pedal her Fat Cat up that same hill, even though it's 3 times heavier than she is with the life support equipment?  That's why we need electric motors.  Maybe we could make the manual backup thing work with super capacitors, but no mechanical linkage.  You just sit there and crank the generator over for a minute or two and then you have enough juice to climb over rough terrain.  In normal ops, you have the circuit closed and the juice goes directly from the generator to the super caps to the hub motors on the wheels and you move about that way at low to moderate speed in permissive terrain.  That does away with mechanical linkages / chains / gear teeth that might snag the suit or get obstructed / bent / shredded by abrasive dust and sharp rocks.  Run the wiring through the frame so there's no exposed wiring.

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