From: Terry Kok To: Dean Calahan, FoB Subject: digest 9 Date: Wednesday, May 10, 2000 4:14 PM

[ to Mars Society Arctic Base TF & discussion ] [ from Kmicheels@aol.com ]

In a message dated 4/6/00 8:09:25 PM EST, curtis@baloney.com writes:

<< this sort of thing was talked about at a couple of Case for Mars` for vehicles getting to and back from Mars as a shield against cosmic rays and solar flares mainly to get away from having to build a small shielded (read "mass penalty") safe haven for the crew during radiation "events" etc>>

The problem with the 1m water shield is that a mass of 40+ MT would be required to shield a habitat from all GCR, if the hab was a typ. 6 crew / 300m^3 vehicle (Cohen, 1996 / 1997). Current thinking is to allow for an "acceptable" level of GCR to enter the hab, mitigating it to some degree with water or other high hydrogen bearing material (polyethylene) to a thickness of 4gms/cm^2. Even so, an area of the hab must have a shielding level of at least 30gm/cm^2 for protection against SPE (solar flares). This equates to roughly 30cm of water. Transhab uses 10cm around the crew quarters, since it obtains some protection from Earth's atmosphere. Consequently, a Mars transit vehicle must have at least 4gm/cm^2 in the outside walls to attenuate galactic cosmic radiation, and a safe haven for protection against solar proton events. kam

[ to Mars Society Arctic Base TF & discussion ] [ from Curtis Snow ]

At 15:50 -0400 2000.04.07, Kmicheels@aol.com wrote:

>The problem with the 1m water shield is that a mass of 40+ MT would be >required to shield a habitat from all GCR, if the hab was a typ. 6 crew /300m^3 vehicle (Cohen, 1996 / 1997). Current thinking is... we have to carry lots of water to Mars the first few trips no matter the crew level so we might as well make the best use of it we reasonably can

>...Consequently, a Mars >transit vehicle must have at least 4gm/cm^2 in the outside walls to attenuate galactic cosmic radiation, and a safe haven for protection against solar proton events.

since the logic is to accept a given level of GCR across the voyage time profile with Mars surface operations probably being the least protective against dosage, I `d say any article that goes on the voyage should be looked at in the shielding considerations so as to leverage our mass...this includes solid (crew) waste storage shielding considerations also impact the timing of any missions since, as I recall, the GCR flux is more an issue during solar minimums more data should be available after the current maximum as to the variations

Mars Society Civilization & Culture Group email: civ-culture@chapters.marssociety.org www: http://home.marssociety.org/civ-culture/ Date: Fri, 7 Apr 2000 16:21:51 EDT From: Tanstaaflz@aol.com Subject: Re: [Civ-Culture] (FAF/GRN) Introduced animal species In a message dated 04/07/2000 01:29:11 PM, ender@axs.com.au writes: << What do people think about the idea of taking earth-born animals to Mars? >> I participate on the Arctic-Mars list where a task force has been set up to design a working biological life support system that can eventually be integrated into the arctic simulation outpost. This is one of the topics we have been talking about. The first animals to go will be the pollinators and they will probably be worked in as our agricultural areas become too extensive to continue hand or feather pollination. On Earth, pollinators include the various species of bees (and there are stingless Australian species), wasps, ants, beetles, butterflies and some vertibrates like bats and humingbirds and some other birds, maybe even squirrels. We'll have to start with simpler less complex ecosystems which call for pollinators that are less demanding of colateral habitat. Many experimental back to nature self-sufficiency solar input gardening experiments on Earth have found that talapia, a pretty good tasting fish I hear, work very well and thrive in water that is in the process of being recycled. So they become part of the life support system as well as a welcome source of protein. So we probably won't be bringing in animals just because we want them (I would find it very hard to live without pet dogs) but because at this or that stage of our growing mini-biosphere we need them as integral parts of the ecosystem we depend on for food and fresh air and fibers and other uses. We are all, the world over, aware of the mistakes made in Australia. So as we added new animal species, we'd have to be pretest them for compatibility with the ecosystem we've already got going. If we wreck our enclosed mini-ecosystems on Mars, we'll literally be out in the cold with just a spacesuit and nowhere to go. Long term, who knows. Just for the fun of it, imagine a resurrected (Jurasic Park style) pterodactyl flying over Mars canyons. Look great, wouldn't it? All we can do is look at the beginnings. Peter

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In a message dated 04/07/2000 05:11:22 PM, dean@baloney.com writes: << initial response about radiation from the sulfur lamp >> I believe that Fusion Lighting Corp. expects to be able to replace the magnetrons with solid state devices in a couple of years. At least it says so on their web site FAQ page Does that alter things? Peter

[ from "Dean Calahan, FoB" ] [ see end of message to unsubscribe ] Here's the initial response about radiation from the sulfur lamp. Now here's a question: How much less than the normal range for a microwave oven, is good enough? Are there any other specific questions I should ask this guy? Steve Braham, you're the Craternet guy, what is your take on this? ----- Original Message ----- From: Steve Factor To: Dean Calahan, FoB Sent: Friday, April 07, 2000 3:52 PM Subject: Re: What frequency(ies) of microwave radiation is used in the sulfurlamp > The FCC requires shielding to prevent interferance. Leakage from the lamp is well below the normal range for a micorwave oven. > "Dean Calahan, FoB" wrote: > I'm thinking that your lamp would be useful in remote operations, at the end of a long logistical chain. However, at the end of that chain, there would be a local wireless network set up. I would hope the noise from the microwaves wouldn't interfere with that.

[ from Kmicheels@aol.com ]

In a message dated 4/7/00 3:56:21 PM EST, curtis@baloney.com writes: we have to carry lots of water to Mars the first few trips no matter the crew level so we might as well make the best use of it we reasonably can. In our transit hab we will carry enough water for drinking and food rehydration, for the trip out and an emrgency free return (say 1.5 yrs). So...that is 3270 (6 crew) person-days x 2.84kg (from NASA std 3000)/person-day=9286.8kg. This same water will be cycled through redundant vapor compression ditillation (VCD) units (or sim. tech.) thus allowing abundant water for bathing, washing, drinking, etc. If the VCDs break down, there is sufficient water to drink for the duration of the trip to Mars, or home. This amount of water + waste is enough to provide a 30gm/cm^2 shield around crew living quarters as an SPE shelter. It is not enough to shield the entire spacecraft. Other materials will be used in the envelope of the hab to mitigate GCR. Additional water may be produced on the surface via ISRU, and need not be carried in the hab.

<< since the logic is to accept a given level of GCR across the voyage time profile with Mars surface operations probably being the least protective against dosage, I `d say any article that goes on the voyage should be looked at in the shielding considerations so as to leverage our mass...this includes solid (crew) waste storage>>

Of course. Waste, stores, equipment may all be configured to enhance shielding.

<>

Thats correct.

<>

Without a doubt, as it seems a very active period.

kam

From: "Andrew M. Salamon" | Block address Subject: [mars life support] Literature review

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Addresses

This is all old stuff, but it's what I had on hand. The last two are the only articles I actually have, and the very last one has another dozen or so references that I'll try to post at some point. Is stuff this old of any use?

Talbot, J.M.: Life Support in Space Operations. Air Univ. Rev., vol. 16, 1965, pp. 42-52.

Miller, R.L.; And Ward, C.H.: Algal Bioregenerative Systems from Atmosphere in Space Cabins and Closed Environments. Meredith Publishing Co., 1966, pp. 186-222.

Ward, C.H.; Wilks, S.S.; and Craft, H.L.: Use of Algae and Other plants in the development of life support systems. Am. Biol. Teach., vol 5, no. 7, 1963, pp. 512-521.

Hannan, P.J.; Shuler, R.L.; and patovillet, C.: A study of the feasibility of oxygen production by algae for nuclear submarines. U.S. Navy Res. Lab. Rept. 5954. 1963.

Bongers, L.: Sustaining Life in Space - A new approach. Aerospace Med., vol35. 1964. pp. 139-144.

Foster, J.: Research on techniques and procedures for the cultivation of hydrogen-fixing bacteria. Prog. Rept. NASA contract NASr-100(03). No. 136-02-903, 1965.

DeCicco, B.T.: Genetic Studies of Hydroen Bacteria and their applications to biological life-support systems. Prog. Rept., NASA Grant NGR-09-005-022, 1965.

Bongers, L.; and Kok, B.: Life-support systems for space missions. Developments in Industrial Microbiol. vol. 5, 1964. pp. 183-195.

Del Duca, M.G.; Huebscher, R.G. and Robertson, A.E.: Regenerative Environmental control systems for manned Earth-Lunar spacecraft. IAS National Meeting, Man's Progress in the Conquest of Space, 1962.

Olcott, T.M.; Conner, W.J.; and W.M. Helvey: Manned Test of a Regenerative Life Support System. Aerospace Medicine. 40(2), 1969. pp. 153-160.

Chamerland, D.; Knott, W.M.; Sager, J.C.; and Wheeler, R.: Controlled Ecological Life-Support System: Use of Plants for Human Life-Support in Space. J. Florida M.A., vol. 79, No. 8,1992. pp. 537-544.

Andrew salamon@home.com http://memebers.home.net/salamon

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