New Mars Forums

As we rapidly approach the MarsDrive plan, it also occurs to me that even better than doing suborbital flights might be to simply put your hab on wheels and drive it around.  If your driving speed is 15 km/hr you can travel 1000 km in a few days and then park for an arbitrarily long period of time.  Even if you desire to circumnavigate the Martian globe, it would take less than 100 days (Circumnavigating Mars is 60 days of continuous driving at 15 kph, so I'm allowing for slow stretches and detours) out of your 550 day surface stay to do so.

Now that's mobility.  And Zubrin's hab masses about ten tonnes, comparable to a medium-sized truck.  What I'm trying to say is that if you can build yourself a reliable enough propulsion system, a hab-on-wheels design really isn't that bad of an idea.  100 days of continuous driving at 15 kph is 36,000 kilometers (22,000 miles).  There are cars on the road doing just fine with ten times as many miles on them, and this kind of one-speed, slow driving isn't particularly bad for an engine.

I don't foresee deployment of PV panels as a problem. Another point - if you have pre-landings the fuel production could be run over several years, reducing the power requirement, I would have thought i.e. if you thought the fuel production would take a year, were we to run that over 8 years, we might need only 12-15 Kws equivalent of PV panel.

I doubt it.   The Mars mission plans NASA has aren't too be taken seriously anyway, so I don't see why they Would address the issue.

I don't think you would need to bury the bags, since there's not much in the way of surface disturbance on Mars like there is on Earth.

Something else I've thought of would be the inclusion of gold microparticles in everything, including food.  They're biologically inert and geologically rare, so their presence would be a sign of human contamination which would allow for some estimate of whether or not organic compounds found on site are indigenous or simply result from the human presence.

Interesting location, and beautiful picture. I pointed this out to a friend, who printed a high-resolution colour image and framed it. It's on his wall. But it's too far north. For warmth, and to avoid winter all together, I would like to restrict the landing location to between the northern and southern tropic.

One issue is that subsurface water is plentiful close to the poles, rare close to the equator. But you want to be close to the equator. So how do you find both? Elysium Planetia is the bottom of the dried up ocean basin. Most of that basin is in the northern hemisphere, but Elysium Planetia is where it extends south and actually crosses the equator. The pack ice is just 5° north.
http://www.space.com/812-ice-packs-meth … -life.html

The ice exists in a block that resemble polar ice on Earth, according to the research team. It measures about 497 by 559 miles (800 by 900 kilometers) and averages up to 150 feet (45 meters) deep.

I should point out, I complained there was no location that met all of my criteria. Then members of NewMars reminded me of the pack ice. Ok. That's now my favourite location.

JoshNH4H wrote:

I'm quite surprised that the mini-magnetospheric plasma propulsion idea hasn't gotten a lot more press/funding in general.  It seems to me that it has the ability to have a higher thrust per unit power than any other form of electric propulsion.

And that's the problem. The only researchers to get funding have attempted to produce a magnetic sail. Instead of radiation shielding, they're trying to produce propulsion. But any sort of "sail" will always be very low acceleration, very slow. And when you talk to congress, as soon as you say the word "sail" they'll think of wooden sailing ships. But space is supposed to be high-tech, not old and slow low-tech. That is what they think. I haven't met any US congressmen in person, but I've gotten to know a lot of Canadian politicians. If you pitch this as a Star Trek force field that can protect against radiation, then you will get funding.

force field = funding
propulsion = dead

Mars Direct, devised by Dr. Robert Zubrin and Dr. Baker, used a 180 day transit, 425 day surface stay, and 180 days back. Also bring empty sand bags and a shovel. Astronauts would fill them with Mars dirt and pile them on the roof. It would only be one layer deep, not 2 metres, but still provide some radiation shielding.

My criteria for location: low altitude (more radiation shielding), near equator (warmer, no winter), flat and smooth (safe to land), and identified subsurface water ice. Definately below the datum, the lower the better. Some valleys have water, but landing in a canyon is very dangerous. The only location that meets all this criteria is Elysium Planetia. Hellas Basin is deeper, but not within the tropics.

I have posted before about the mini-magnetosphere. Also posted a link to the University of Washington. But you're a medical doctor, so more qualified than me.

We normally talk about 180 day transits, rather than 120.  The reasoning for this is that 120 day transits have excessively high delta-V requirements which makes them more-or-less unfeasible.

Having said that, are these claims of radiation effect alleviation stemming from legitimate medical research, or are they proffered by the same people who are pushing "Homeopathic 'Medicine'", "Herbal Supplements", "'Alternative' 'Medicine'", or any of that nonsense?

From what I read,  the galactic cosmic radiation (GCR) varies with sunspot cycle,  every 11 years.  Minimum GCR at solar max is 24 rem/year,  and maximum GCR at solar min is 60 rem/year.  NASA astronauts currently have a limit of 50 rem/yr. 

We don't violate that limit by very much at all,  worst case,  and stay well under it most of the cycle.  Close to max exposure,  one starts bumping into career limits with younger astronauts if the mission runs over 2.5 years.  And that doesn't take into account the half-sky shielding effect of the planet for the approximately 1-year stay at Mars,  nor the slight shielding effects of spacecraft structures (admittedly very slight).  Nor does it consider atmospheric shielding at Mars,  which is more effective than any of us had hoped.  But,  the crew that makes this trip doesn't need to fly one like it again. 

Radiation that kills is more likely a big solar flare event.  The worst of these only needs about 20 cm of water for an effective shield.  Any craft on a 2.5 year voyage will have water and wastewater tanks.  You just wrap them around your designated shelter zone.  The smart designer would make that the flight control station. 

Radiation as a reason not to go to Mars is an canard and an excuse.  We've known what has to be done for a few decades now.  And we have known how to do it for those same decades now.

GW

Ice worms were first discovered in 1887 on Muir Glacier in southeast Alaska by George Frederick Wright, a glacial geologist (who doubled as a theologian) in 1887. However, the discovery was more or less ignored for most of the 20th century. Only very recently has any real effort been made to subject them to thoroughgoing scientific enquiry.
The coastal glaciers that serve as ice worm habitat extend from Mount Rainier in Washington State to Alaska.
Ice worms, which are a relative of the common earthworm, have no eyes, so they don't see images, but they respond to light and dark. At a little less than an inch long (one to two centimeters), they are often described as looking like pieces of dark thread in the ice.
They have big mouths, said Shain, and their primary food source is the red algae that grows on glaciers. Their ideal temperature is zero degrees Celsius (32 degrees Fahrenheit); at 5 degrees Fahrenheit they start to disintegrate.
They spend their days burrowing up and down through the ice. Biologist Dan Shain  remarks that "They definitely operate on some kind of Circadian rhythm, moving up when it's dark and down when it's light."
Ice worms propel themselves using setae, extremely small bristles that protrude from the sides of their bodies. Wriggling through fractured ice and snow crystals, they burrow as deep as three to six feet (one to two meters) beneath the surface of the ice.  They have mysterious head pores which might be producing some sort of lubricant to help them move through the ice.
They can live in colonies of a few hundred thousand to 20 million, covering an area as large as 30 acres. No one knows how long they live. Beyond the occasional bird or two, the only threat to their existence may be global warming.
Although temperatures on Mars are probably too cold for our cosseted Earth-bound  ice worms, one can imagine that something like an ice worm might be able to live out life in the huge Martian glaciers. If so, then once again it is unlikely that our presence will threaten them. It is probably a case of ourselves having to exercise a degree of caution in choosing our water sources and in filtering and sterilising the water.

You shape your vehicle of docked modules as a baton that spins end-over-end,  with the habitat at one end.  This is an inherently stable configuration,  as anyone who has ever seen the baton twirlers at a football game can testify.  It integrates well with staged-off empty tanks:  your baton just gets slimmer.  There's no need for a truss,  just connect the tanks axially and laterally. 

GW