Living Energetically on Mars

JCO · 2015-01-27 19:43:24

There is a post in the transportation topics about riding bikes on Mars. For pure transportation purposes a human powered vehicle will likely be able to move at an equal speed and with the same safety as any other power source. It also provides another benefit that could be very valuable to explorers and colonist on Mars, exercise. The prolonged exertion of human powered vehicle could be very effective at combating muscle and bone loss.

That brings me to the point of this post. I think the key to humans health on missions will be identifying tasks where human effort will be as effective or more effective than a machine. The challenge would be to identify ways to efficiently make use of human effort. At the moment I can think of one other task that may fit into this category, digging. Humans may actually prove to be more efficient at digging in the regolith then a machine that could conveniently transported to Mars. Because of the difference in gravity digging on Mars may feel more like shoveling snow and any rocks smaller than a person would be fairly easy to move.

What do other think would be tasks that would make good use of human power?

SpaceNut · 2015-01-27 19:58:45

These tasks would be difficult in a space suit but would prove good, inside as you say for the crew but in a domed environment but of course we are talking about a time way off into the future.

JCO · 2015-01-27 21:30:48

If mechanical counterpressure suits are used it would likely allow the wearer to be quite active. Your comment does suggest that most of the activities I am suggesting would need to be outside as there is limited space inside the habitat for activity.

I mentioned in the transportation thread that because of the martian gravity a vehicle with a pressurized cabin would likely not be too heavy to be human powered.

Impaler · 2015-01-27 23:22:51

Small electric dirt-bikes make a lot of sense on Mars, they would have a considerable range, would be light enough that it a person could lift them making it impossible to become stuck as well as strap onto the side of other vehicles like ATV's to act as self-rescue vehicles or for taking brief forays into especially rough terrain.

But pedal power just doesn't sound viable too me, people just cant produce the force necessary to take a wheeled vehicle up significant inclines especially over rough ground. Virtually all pedaling done on Earth in a bicycle is on a compacted road or trail, even mountain biking is done on mountain bike trails and is generally more downhill then up. And it's done by people at peak physical fitness with unlimited oxygen supplies. Human metabolism can use up Oxygen a LOT faster then normal when under high exertion, your likely looking at using up EVA oxygen supplies in 1/4 the normal time frame if people are exerting like that.

And MCP suit is utterly impractical for a dozen separate reasons, fortunately we have next generation suits in development that would be up adequate for Mars surface, I repeat ADEQUATE for walking, riding vehicles, exploring and working, not fantasy suits that let you forget you are in a lethal environment.

Last edited by Impaler (2015-01-27 23:32:00)

GW Johnson · 2015-01-28 13:19:25

I think there's role for both motorcycles and bicycles on Mars, maybe tricycles or quadricycles instead. The human-powered stuff will require graded roads. I rather doubt that'll work well in the rough, off-road. Not wearing spacesuits.

Paul Webb's "elastic space suit" of 1968-vintage didn't look all that impractical to me, especially in the film clip of the test subject pedaling a bicycle ergonometer inside a vacuum tank at the air pressure equivalent to 87,000 feet. It was just a bitch to don the thing. He had all kinds of mobility not seen since the full p-suits of Mercury, which would not have been adequate for an EVA because of no cooling for the wearer. The suits grew in bulk and restriction when they were made adequate for EVA, starting in Gemini, and culminating in the Apollo moon suit. It's only gotten worse since then.

To go outside in space with Webb's elastic thing, all you needed to add was an ordinary white insulated coverall (or insulated pants with a separate coat), a helmet visor, insulated booties, and insulated gloves. To go EVA on the moon (what Webb was working toward), swap out insulated hiking boots for the booties. If it would work on the moon, it would work on Mars. Too bad nobody ever tested further to find out.

All immature technologies need some development to make them "practical". MCP is getting a pittance at MIT for Dava Newman's work, but could be matured quickly if multiple avenues were funded significantly.

That being said, the same immaturity vs maturity is true of nuclear rocketry. That's a different ball game cost-wise, but the same sentiment applies. There was some effort funded by one of the intelligence agencies in the 1990's to resurrect a variation on the old NERVA work, I think in response to some 1980's work by the Russians in the same area. I don't think either the US or Russian efforts ever led anywhere significant. But ours did confirm decent life, decent Isp, and better thrust/weight than the old NERVA rig. NERVA was close to flight test (but not spacegoing application) in 1973 when the effort died. It was about a year from its first flight test, as a replacement 3rd stage for the Saturn-5.

Now gas core was (and still is) quite exploratory, and that situation is still unchanged, because no one has worked on it. All that ever got done was academic-scale funding of two bench-top tests. One was a plasma flow experiment to test the fluid dynamic scheme necessary for essentially perfect containment of a U-233 (? not sure, might have been HEU) core in an open-cycle design. The other was a successful demonstration of a controllable HEU reaction in the gas phase. Both were successful feasibility demos, not mature technology demos.

At the time, the best estimates of contractors like Pratt was that regenerative cooling would be adequate in gas core up to about Isp 2000-2500 sec (with engine T/W around 30:1). Above that power level, some sort of active radiator cooling was needed. They thought Isp up to 6000+ sec might be possible, but that the radiator system cut T/W well under 0.1, maybe under 0.01. No test data ever backed these assessments up though. Gas core was a neglected and underfunded second stringer to the main event, which was NERVA. We know just enough to know it would probably work at one level or another, if we were to actually develop the thing.

The other widely-ignored nuclear option is nuclear explosion propulsion. This was General Atomics in San Diego, starting about 1954. It culminated in USAF-funded work from 1959-1965, when USAF had to turn all its space stuff over to NASA except for MOL and the spy satellite programs. NASA saw it as a competitor to NERVA, instead of the complement that it really was, and so NASA killed it by defunding it.

Enough experimental work was done to verify the principle: (1) they flew a 1-meter model with pulses of high explosives, and (2) there was data from the atomic bomb tests to well-support the survival of the pusher plate.

Enough design analysis was done to find out the explosion propulsion principle works far better in larger sizes (10,000 tons and up). It wasn't any better than NERVA in the small sizes NASA was considering for its then-planned Mars trip in 1983. That was used to help justify killing it.

Enough design analysis work was also done to figure out that the total fallout from surface-launching one of these 10,000 ton ships to LEO was equivalent to only one 9 megaton warhead atmospheric test today. No one would have been hurt by our building a fleet of a half dozen of these things over a decade. We're talking about a giant spaceship built of steel the same as a naval warship.

It wasn't until the Starfish Prime test over Johnston Island that anybody understood what the real side effect to be feared actually was: EMP effects. This can be managed, but the flight path restrictions, and the restrictions on construction shipyard locations, are very severe. And that applies to departure from orbit, too. I wouldn't recommend this technology for exploration missions, but for major colonization efforts maybe a century hence. And bear in mind that we can build better explosion devices than that 1950-vintage fission stuff.

One last comment about nuke explosion drive. The efficient form of the devices is a strongly-shaped charge. Those are lousy as blast weapons, and omni-directional blast weapons make lousy explosion drive devices. I know both are "nukes", and the psychology is against doing this, but the devices aren't really suitable as weapons.

Of all the technologies being discussed here, the MCP suit and the explosion drive could likely be brought to maturity quickest, probably as quickly as a ready-to-apply SEP drive. I think we should be doing all of them. They all have niches to fill.

GW

JCO · 2015-01-28 15:17:43

Anyone who thinks that a electric vehicle would be better on rough terrain than a bike has not spent much time on a bike. As a kid would ride my one speed over all kinds of terrain and could carry it over any obstacle I could not ride across. When I road across the country between me, my gear and my bike I was over 250 lbs. The equivalent on Mars would be a vehicle with the mass of 1500 lbs. The Smart Car has only a slightly greater curb weight. Though I was active I was far from 'peak' physical condition when I began a trip of 4,000 miles. The people we send to Mars will likely be in much better shape than I was. A large portion of the world use human powered vehicles for transporting people and goods. People regularly ride over more difficult terrain then any motor vehicle can navigate.

I think a recumbent trike design would be prefered. The suits used on Mars will be much better than current designs but will likely still be be as restrictive as a wet suit. A trike would be much easier and comfortable to operate. A trike could be designed to carry substantial cargo and even passengers. A human powered vehicle does not require much more effort than walking. The driver of the trike could likely travel 50 miles in a day without a great deal of effort.

kbd512 · 2015-01-28 15:38:49

Exerting yourself in a spacesuit is not a particularly good idea and our space program and the Russian space program has confirmed that.

Riding a bicycle on Earth with no oxygen availability constraints is hard enough. It's also easy enough to fall off and be injured, which is probably not something you want to do on Mars.

The electric vehicles that NASA designs are not race cars, they typically move at a sedate jogging pace or fast walk at maximum speed.

Yes, a large number of people who don't have cars ride bicycles.

A trike on Earth, who is most likely not wearing a space suit, could cover 50 miles a day.

louis · 2015-01-28 17:50:50

JCO wrote:

There is a post in the transportation topics about riding bikes on Mars. For pure transportation purposes a human powered vehicle will likely be able to move at an equal speed and with the same safety as any other power source. It also provides another benefit that could be very valuable to explorers and colonist on Mars, exercise. The prolonged exertion of human powered vehicle could be very effective at combating muscle and bone loss.
That brings me to the point of this post. I think the key to humans health on missions will be identifying tasks where human effort will be as effective or more effective than a machine. The challenge would be to identify ways to efficiently make use of human effort. At the moment I can think of one other task that may fit into this category, digging. Humans may actually prove to be more efficient at digging in the regolith then a machine that could conveniently transported to Mars. Because of the difference in gravity digging on Mars may feel more like shoveling snow and any rocks smaller than a person would be fairly easy to move.
What do other think would be tasks that would make good use of human power?

You mean digging outside? I think you'll need help from a microwave blade - otherwise you would be trying to dig in frozen regolith. Maybe sand I suppose could be moved even in frozen conditions.

JCO · 2015-01-29 00:41:59

kbd512 wrote:

Exerting yourself in a spacesuit is not a particularly good idea and our space program and the Russian space program has confirmed that.
Riding a bicycle on Earth with no oxygen availability constraints is hard enough. It's also easy enough to fall off and be injured, which is probably not something you want to do on Mars.
A trike on Earth, who is most likely not wearing a space suit, could cover 50 miles a day.

Exerting yourself in a BALLOON suit is a bad idea but if we do not come up with something much better there will be no point in going to Mars. If exploring Mars will entail people bobbing around like the Stay Puft Marshmallow Man for 6 months we may as well stay home.

I take it you have not been on a bike recently. Either that or you are incredibly out of shape. Scuba diving can be very strenuous though diver are able to easily carry over an hours worth of air. With the low gravity a much larger life support carried on the vehicle would not be a great encumbrance. As for falling off, that is one of the reasons I suggested the recumbent trike; it is very hard to fall off of.

The ones who question how effectiveness of are recumbent trike know nothing about the current state of the human powered vehicles in the CONSUMER market. http://www.terratrike.com/ This design could be easily modified for rougher terrain and in 1/6th gravity and almost no air resistance 50 or more miles a day is quite reasonable.

JCO · 2015-01-29 00:50:01

louis wrote:

You mean digging outside? I think you'll need help from a microwave blade - otherwise you would be trying to dig in frozen regolith. Maybe sand I suppose could be moved even in frozen conditions.

The ground will be frozen only if there is water in it. As the weather on much of Mars does reach above the melting point of water from time to time the top several meters of regolith will be free of permafrost. Below that level all you will need is a parabolic mirror to heat up the regolith. It will not be a fast process but from experience here on Earth machines do not do any better digging through permafrost. Once the water content of the regolith reaches a certain point it will be harder than concrete.

kbd512 · 2015-01-29 10:12:03

JCO wrote:

Exerting yourself in a BALLOON suit is a bad idea but if we do not come up with something much better there will be no point in going to Mars. If exploring Mars will entail people bobbing around like the Stay Puft Marshmallow Man for 6 months we may as well stay home.

Agreed. We're still working on that. I'm not sure we're putting enough money into it, either.

JCO wrote:

I take it you have not been on a bike recently. Either that or you are incredibly out of shape. Scuba diving can be very strenuous though diver are able to easily carry over an hours worth of air. With the low gravity a much larger life support carried on the vehicle would not be a great encumbrance. As for falling off, that is one of the reasons I suggested the recumbent trike; it is very hard to fall off of.

I walk or drive or fly wherever I'm going these days. I spent most of my childhood riding around on a bike. At 17, I joined the Navy and spent the next six years walking most places and carrying what little I owned. The Navy was anti-carrying-technology, apart from seabags, buses, and aircraft. Everything that could conceivably be hand carried was. I never owned a motor vehicle or a bike until after I left. I'm not saying you can't walk or bike everywhere, but it requires a bit of exertion and our explorers, unfortunately, don't have unlimited oxygen or food supplies.

There's no traffic on Mars, yet, so you don't have to concern yourself by getting flattened by some clown talking on the cell phone in a SUV while you're riding your bike. That's a plus.

JCO wrote:

The ones who question how effectiveness of are recumbent trike know nothing about the current state of the human powered vehicles in the CONSUMER market. http://www.terratrike.com/ This design could be easily modified for rougher terrain and in 1/6th gravity and almost no air resistance 50 or more miles a day is quite reasonable.

I'm not opposed to the idea of human powered travel, even on another planet, but how do we test all of this? Has anyone used one of these advanced consumer recumbent trikes when it's -100 outside? Whether the vehicle weighs 38% of what it does on Earth or not is of little consequence if you load it down with enough supplies. Have you figured out how are our explorers going to eat, take a dump, or replenish the oxygen for their suits (shouldn't be too hard)? How much would a pressurized HPV weigh? Could you use the HPV as shielding against SPE's?

JCO · 2015-01-29 14:09:36

kbd512 wrote:

JCO wrote:
Exerting yourself in a BALLOON suit is a bad idea but if we do not come up with something much better there will be no point in going to Mars. If exploring Mars will entail people bobbing around like the Stay Puft Marshmallow Man for 6 months we may as well stay home.
Agreed. We're still working on that. I'm not sure we're putting enough money into it, either.

I think it is a safe bet that it is way underfunded at the moment. Even so there are 2 programs developing MCP suits. The budge to bring the technology to maturity will be miniscule compare to what it will take to design a habitat that will keep a crew alive for up to 2 years. Once funds for the big thing are available there will be more than enough money for the smaller projects.

kbd512 wrote:

JCO wrote:
I take it you have not been on a bike recently. Either that or you are incredibly out of shape. Scuba diving can be very strenuous though diver are able to easily carry over an hours worth of air. With the low gravity a much larger life support carried on the vehicle would not be a great encumbrance. As for falling off, that is one of the reasons I suggested the recumbent trike; it is very hard to fall off of.
I walk or drive or fly wherever I'm going these days. I spent most of my childhood riding around on a bike. At 17, I joined the Navy and spent the next six years walking most places and carrying what little I owned. The Navy was anti-carrying-technology, apart from seabags, buses, and aircraft. Everything that could conceivably be hand carried was. I never owned a motor vehicle or a bike until after I left. I'm not saying you can't walk or bike everywhere, but it requires a bit of exertion and our explorers, unfortunately, don't have unlimited oxygen or food supplies.

This is a much bigger discussion that I cannot claim any real expertise in. What I believe is that we will need to grow food on any mission to Mars. If that is the case recent studies have suggested that there will be a surplus of oxygen produced. I think for the power level of most transportation on Mars humans will be more efficient than any motorized solution. One of the big factors in this is the energy density of humans. Think of the size of battery you would need to carry your Navy gear all day and compare it to the size of the 3 squares you got.

kbd512 wrote:

There's no traffic on Mars, yet, so you don't have to concern yourself by getting flattened by some clown talking on the cell phone in a SUV while you're riding your bike. That's a plus.
JCO wrote:
The ones who question how effectiveness of are recumbent trike know nothing about the current state of the human powered vehicles in the CONSUMER market. http://www.terratrike.com/ This design could be easily modified for rougher terrain and in 1/6th gravity and almost no air resistance 50 or more miles a day is quite reasonable.
I'm not opposed to the idea of human powered travel, even on another planet, but how do we test all of this? Has anyone used one of these advanced consumer recumbent trikes when it's -100 outside? Whether the vehicle weighs 38% of what it does on Earth or not is of little consequence if you load it down with enough supplies. Have you figured out how are our explorers going to eat, take a dump, or replenish the oxygen for their suits (shouldn't be too hard)? How much would a pressurized HPV weigh? Could you use the HPV as shielding against SPE's?

The best way to test it is build it first for the Moon. If we can make one that works on the Moon we will be able to make one for Mars. My example was not a suggestion for the exact design of a vehicle for Mars but an example of the maturity of HPV technology. It will not be rocket science to adapt known technology for the martian environment. The ideal that the HPV may be too light to work efficiently on Mars is an interesting on. A good size CO2 scrubber and O2 tanks might be useful in providing enough mass for the HPV to be easily controllable. It would be very possible to build the suits to accommodate biological needs for an entire day but I do not think it very practical. This would suggest that any outside activity would be limited to about 4 hour periods. This would be the same no matter what mode of transport was used.

Reconsidering a pressurized cabin for a HPV I think it is possible but the airlock for it would likely make it impractical. You may be able to make one using the airlock suits being developed but that would be a more advanced design then you wanted to send with the first explorer.

I do not know a great deal about radiation shielding but I know shells for HPV are not uncommon. I see no reason that one could not be built that would provide some additional shielding. This will likely be important for any transport on Mars. Because of the longer excursions outside the open dune buggy design of the lunar rovers will be much less practical.

BTW: Factual error on my part. For some reason I was recalling martian gravity as 1/6th Earth not 1/3rd. So I was pushing the martian equivalent of only 1/2 a smart car on my trip.

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#1 2015-01-27 19:43:24

Living Energetically on Mars

#2 2015-01-27 19:58:45

Re: Living Energetically on Mars

#3 2015-01-27 21:30:48

Re: Living Energetically on Mars

#4 2015-01-27 23:22:51

Re: Living Energetically on Mars

#5 2015-01-28 13:19:25

Re: Living Energetically on Mars

#6 2015-01-28 15:17:43

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#7 2015-01-28 15:38:49

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#8 2015-01-28 17:50:50

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#9 2015-01-29 00:41:59

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#10 2015-01-29 00:50:01

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#11 2015-01-29 10:12:03

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#12 2015-01-29 14:09:36

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