PB666

What you showed [VIdeo of Cylindrical Habitat] is physically not possible based on current materials science. A cyclinder even 1/10th that diameter (e.g. babylon 5-ish) is still difficult, I would argue. A larger cylinder is a larger target and asteroids traveling around at 20-70 km/second, the shielding on such an object would have to be massive. The third problem is that your source of energy would be entirely artificial since, 1. The ends hold up the floor and glass is not structural, but sheathing. 2. The length of the structure either has the light always coming in at an oblique angle or a reflector (not shown). The optimal structure is a much thinner disk where the light come in the center as is reflected to the sides by a mirror. This is much thinner and allows more colonies and less risk of a catastrophic failuer for each colony. The Mass required to build just one of these and provide ambient non-inertial reference frame comparable to earth's surface is well beyond any serious proposal. You must find a source of mass in space first and a means of converting mass into the basic elements required to build such structures. We can think of it like this, The earth, the place you stand, coalesced over 5 billion years, the heat it gained during coalescence has been evolving also for 5 billion years, energy that has been lost to the earth. To create earth like environment in space you have to impart all the ambient (non-radioactive, no solar hv) heat that the Earth has lost during the 5 billion years. Also, your gravity, is not what you think, If you drop a ball its on a sub-orbital trajectory. If the earth is not there (but somehow the energy is) it go into a orbit about that point a barycenter between the earth and the moon. If we take the briefest moment of motion you are in orbit, at the end of that moment the Earth steps in to force you back to where you were. It is the stacks of matter that are pushing you up. While it does not appear to be the case its a dynamic equilibrium that occurs between all objects on the surface in motion, the appearance of immobility is due to the way relative motion appears. An example of this dynamic are objects floating on the tides as the tides role around the Earth. If you read the articles on the Cartesian coordinate system they point out the Z coordinates for all objects relative to the earths true center are always changing at least twice a day sometimes 4 times a day the motion changes. While the structural aspects of the Earth are able to resist most change, they cannot resist all changes. Because the motion is very slow its all but unnoticeable. This change is very minor with small spherical and compact objects in space that try to maintain a non-inertial g-force on the surface, but as objects get more massive these shifts in force become more apparent. If you have an extremely massive structure and you spin it to simulate earths surface gravity the sun (or other local bodies) will cause that structure to begin pulsing. IN order to prevent damage that structure would need to be heavily braced from its center. Lets imagine a cylinder 10 km across. To achieve 9.8 meters per second you need a velocity of W2R. 0.98/1000 = w2 . omega = 1/31.6 radians per second (About 2 degrees). The entire structure making a revolution in about 3 minutes. If you were inside the structure you literally would hear it creeking and cracking, houses would be in a constant settling. Nails would not be used because they would eventually be pulled apart.

Martian Atomospher : Carbon dioxide (C)(O), Molecular Nitrogen (N), Argon (Ar), Carbon Monoxide (C)(O), Perchlorates(Cl)(O), Martian Soil: https://en.wikipedia.org/wiki/Martian_soil#/media/File:PIA16572-MarsCuriosityRover-RoverSoils-20121203.jpg Note the presence of Na20 and CaO. In the presence of water at any appreciable levels and carbon dioxide Na20 form Na2CO3 and CaO will form CaCO3. The lack of detection of either of these is a general indication of dehydrated soils and the lack of moisture. This is another incredible risk for Mars, the soil is incredibly alkaline. So at least at the mid latitudes water is going to be extremely difficult to come by. Let me rephrase this lest I be confused. With Fusion power you can survive anywhere on Mars, and water is available at teh Poles, although there may be soil stability problems. Without fusion power you are dependent on solar power at midlatitudes, which means Martain water is likely deep within Martian crust.

3D printers are good for making models and plastic cooling fans. Wont help you much with an integrated circuit board or a 12 feed power supply. You really have no idea what breaks on these pieces of equipment. Let me give you some 30 years experience managing a lab. Power supplies (blown capaciters and short circuited transformers), integrated circuit boards, on several occasions photomultiplier tubes, belts frequently break, but there is also the seizing up of bearings (which sometimes need to be lubricated), clogged hepa filters (some of which cost 1000s of USD). None of this cheap ______ electronics is suitable for a journey to mars, switches and electronic power transformers (the current favorite of the small machine industry) are not suitably reliable for such a journey. Long term refrigeration, I seen 2 -80 freezers blow before their 5th birthday, you are not going to repair that type of equipment in flight (older models or much more reliable but the CFCs are now banned by international agreement). Overheating of equipment that was built in too small form factor. Glass or plexiglass can spontaneously shatter under stress, teflon parts (such as on those dreamt about human centrifuges) can wear down. Of course you can have complete short to ground in the motors of major equipment (creating 1000s of dollars worth of instant space junk). Water leaks did 10,000s of damage to some electronics, brown-out destroyed one entire system. Fancy equipment needs alot of robust infrastructure to give longevity. Lets talk about the other problem those perchlorates on Mars, how are you going to remove them from the EVA suits before the folks get back into the station. Perchlorates plus humidity = short circuited electronics.

"Pay attention to dust production and accumulation.Dust contamination is a common issue in ISS"

http://www.iausofa.org/2017_0420_F/FundArgs.html The subfiles give listings in Fortran77 of the Mean anomoly from J01 2000 12:00 PM (which turns out to vary depending on what time model you use).

The ISS could be larger, particularly now that its been moved to a higher orbit. This is the major difference between the ISS and what you place on Mars. If you are aerobraking down to the planet (Thrusting down can cost as much at 4500 dV), the size of something is very important. Friction is a function of surface area, but force is a function of mass, mass that exist in 3-dimensonal space. As you increase the size of a sphere with constant density the equilibrium velocity at any given air density is going to increase. So for instance if you double the volume the equilibrium velocity increases by 20 to 40% and so on. The issue of size with the ISS, if we recall the complaints that have been repeated here ad-nausea in the past, was that the designated habitat launch vehicle was the STS. The STS has a limit on size given its cargo bay. It is not necessary a limitation on weight, but exterior volume only. Overtime the space shuttle was equipped to launch even more mass and could have launched habitats even double the weight (41% larger diameter) BUT could never launch structures of larger diameter. As a consequence the Shuttle is what determined the form-factor of the space station. Today there are many options, including ION driven systems to help station the ISS. With more efficient launch vehicles there is no problem getting humans or supplies to much higher orbits than previously desired. We also forget that the STS is not the biggest or most payload worthy rocket that has been produced. THe primary problem with Payload Diameters is the aerodynamics below 30,000 meters. Part of this can be circumvented by launching and Alpine altitudes (also increase ISP) that establishes a Max Q at a higher altitude. Does anyone want to see my space factory? The design was supposed to have a sealable bay door but I could not work out a way to install it and animate it. I would have to alter the way docking ports work in the game. This particular station runs on a 50MW capable fusion reactor (50T) (Top left, left of bell structure). This particular (core is white part) design is not a single piece its made of 36 side/bottom pieces. The side pieces (constructed of 3 pieces, two of which are pressurized and have enterior structure capable of part manufactoring or assembly. The three veiwing decks in the Top right are added to the interior. These act as a final assembly area for larger parts and have a large door capable of individuals parts up to a meter in diameter. There are 3 docking ports close by as well as a downward facing 2+ meter docking port. This particular was designed to be assembled in space starting with the central 12 sided central access facility with 12 closable doors a viewing area centered by a docking port (2+ meter diameter). The sides of each peice have a rubber gasket and act as a second line of defense against leaks. They are strung together loosely in space and then in a predesignated compartment the bindings are contracted drawing the vessels together once drawn each peice is bolted to the next from inside the pressure vessel using pressure tight mechanism. The End pieces are bolted from the outside together since they lack a pressure compartment. Because of the size of the vehicle and its shape if can be spun to provide a non-inertial environment for crew. When the End plate door is shut the viewing deck is virtually free of cosmic radiation due to the number and thickness of 3 walls. The point I am making is that the ISS was not designed to be a space factory but an STS resourced science station. As such its function dictated its design. As space factory that has a much larger interior volume requirement would demand a much different assembly tactic. Note: While I have not yet lifted the whole launch from RSS, I have orbited the entire factory from the surface of Kerbin (you have to zero gravity on the launch pad until you get lift off other wise . . . ). THere is a smaller version of this that can be launched from Earth and could be used to assemble the parts for this factory.

I am enjoying the RSS mod/addon to the game. The problem has been coordinating launches, particularly since the reference plane is not the solar system plane. I can get around this but the problem I am having is that MeanAnomolyAtEpochD variable lacks any definition that I can find. This problem is compounded by the fact that in the System viewer it is very difficult to isolate and visualize inclination nodes without have equi-orbital objects already in space. There is the J2000 and J1950 and J2011 definitions but there is no EpochD. It sure would be nice to have some kind of formula for each celestial that would give its position at various times. I have already checked the files for Mercury, Venus and Earth. Wouldn't it be great if the Mean and true anomoly were reported as a stat . . .and the periapsis and apoapsis of celestials would appear when you click on them.

There is one thing here I should mention. As long as we are talking about spare parts you don't have exactly the same problem as you do landing and taking off living people on Mars. Landing small objects on Mars is alot easier than landing large objects. You could have a companion ship escort your travelers and parts shipments sent to the surface when need from LMO. Im not trying to minimize the problem but we really have to differentiate two problems. Given an launch window, getting the physical human being to Mars is not a problem that much more complex than putting physical human beings in orbit about the moon. The work required to keep them alive is magnitude harder, but ISS is but a prototype survival unit, improvement have been made. Even so getting even one section of the ISS to the Mars surface is a monumental task. Getting it back in orbit is nearly impossible without better and more efficient engines. So by definition we are going to initially be putting something small and manageable on Mars. This translates to extremely utilitarian structures. The next issue is how to do it. From a basic physics stand point if you want to put people on Mars and retrieve them, each person should go down as a single ship (one that can return to Orbit) but the ship itself would not be a habitat. So the habitat is something that could be assembled on dusty old mars (6000kg Per F9 launch with an ION Driven carrier but size would dictate a decent amount of fuel spent to land). If we are assuming the landed station is built at a time before humanization, then its not a problem to stock pile parts . . . . . . A sealed dumpster on the outside of the habitat could hold parts. Again, since parts are not living and not food . . .you can send them up to Earth L2 have a circulator pick them up and wander to Mars L2 then detach the ship for Mars reentry and landing. I have worked on some of the types of equipment that you might find on ISS. I have repaired a great many pieces of equipment. The largest piece I can recall was a power supply with about 12 different power feeds. It weighed about 15 lbs. Properly wrapped you could probably drop on Mars at 50 m/s and it would survive. These things are small you could drop them an inflatable heat shield over the target site and an airbag on landing, have one of those humans retrieve them. Most everything else are integrated circuit boards (which on many modern pieces means replace equipment). If you are shipping fat to Mars you can simply embed a single wrapped circuit board in the oil and cool it to 4'C, its now protected. lol. Ship it in the food supply. If you are shipping whole grains just put them in the bags of grain. As per the dust issue. . . .I agree . . . . I keep making the argument that the settlements on Mars should be built into the Martian landscape, not on top of them. Its just another in a long list of reasons not to be on the surface. But unless we create much more autonomous mechanobots that are capable of mining Mars and also repairing themselves , the first habitats on Mars are likely to be surface habitats.

That's what I was thinking, and wait until you get into ISRU, drilling holes, repairing EVA suits, Repairing robots, cleaning solar panels. Basically anyone who stays are Mars for a year will be performing diaper duty of robotized equipment they need for life support. The thing about light weight equipment, its often not the most durable version of whatever device it is. The Apollo lander was called a rattletrap during its testing flights.

If money = power then its money. But given the fact that only truely viable deep space power source is one that has yet to have proven itself on Earth (fusion energy). While solar materials are getting more weight efficient and conversion efficient the problem is that these are not stationed arrays, they are flipping out in space. The Russians tried using fission reactors in space, that proved to unweildy because of the plumbing issues involved. Think of the problems that could be solved with power. . .+ radial transfers and - radial stop vectors. (So called 39 days) also limits the travel of Mars past earth making travel back easier. The 39 days (VASIMR) was an ION drive based system, the only problem was they 200 kw required to operate it does not exist. I think the biggest stumbling block at present is the return trip (A Mars launch/orbit) is expensive, even to carry one individual and transfer to another ship (factoring cost from earth) and the additional time required to transit back to Earth. The way Mars looks compared to the lunar mission. 1. More dV for intercelestial transfer. 2. More dV to insert into orbit 3. More mass required to land 4. A whole mission just to supply the return vehicle greater than a single Apollo mission with lower capacity 5. A return mission with a capsul much heavier and elaborate than the command module/capsule. At each point along the way the mars mission is more risky, expensive . However the last two are the most problematic.

That depends. Manned landing mission is not going to be like Apollo, the return window requires a wait, which means colonization aspect means the first men landing on Mars may have to colonize unless a better source of Power in flight can be obtained. My argument is this, we cannot even think about a manned landing mission without proper preparation of the infrastructure on Mars. Footprints and flags only mission is essentially a suicide mission. 0.38 g maybe survivable even long-term, it is more survivable than micro-gravity. We tend to think as colonization as being permanent, but the first colonies in the new world were frequently abandoned or moved. Some were abandoned only to be later reoccupied. It may be the case that that first colonies on Mars are only occupied for a few months at a time until the safe infrastructure for permanent settlement is in place. The question that I posed in the previous long post is that 'can a Mars colony be made feasible enough such that only trivial resupply missions suffice'. I devised a strategy for transporting materials brought by common commercial rocket to LEO. Circulator to LMO, and landing ~6T on mars. The true question here is how much can we expect inhabitants to supply of their food calories and raw materials. If the answer is less than 30% then there is no long term feasibility of a Mars colony. If, OTOH, they can supply 70 or 80% of both, then a single resupply ship can service dozens of colonies within a certain proximity. On the issue of Power these are my thoughts. If you have a High ISP ION drive (5000+ sec), then on circulation back to earth you can afford to be wasteful and chase Earth versus Hohmann intercept. The problem is Power. -Solar panel absortion to power efficiency is creeping slowly from 30, I have seen efficiencies as high as 45, but a circulator will require a very durable solar panel. And still we are talking huge amounts of power. Once the Earth has passed Mars no transfer orbit can catch it until Earth is once can following Mars. As a consequence an Earth intercept transfer has to burn so hard that its periapsis falls below the orbit of Venus and then rises to intercept Earth with positive radial velocity. This will require several thousand more DV than a direct transfer orbit. - If you have a 10,000 ISP engine granting all the extra dV you have to either increase the size of solar panels or the efficiency <------. Because adding solar panels makes the absolute thrust issues more problematic, efficiency. There is a marginal utility of gain when adding ISP (payloads must shrink). So a normal mars return is within the bounds of what ION drives can current do, but beyond the bounds of what current solar panels can do (both efficiency and size). If you replace 30,000 kg of solar panel with a 1 megawatt fusion reactor all your problems except cooling immediately go away. First ION drives are low weight and you can add many. The cost of fuel shrinks. You now have both thrust (interplanetary worthy no launch to orbit worthy) and you can plow to a mercurial orbit and back to earth and stop at a reasonable altitude, transfer the pilot to a return station and go back to Mars again. The problem is not so much a strategy for getting to Mars, getting Elon to Mars is doable, even landing him there alive in a coffin is doable (he would survive, pretty sure) keeping him alive for more than a few months or longer with resupply is not much of a problem either (still not a colony though) . We simply lack the power to get him back in a timely manner. Assuming a transfer ship and a coffin (1000 kg) plus a passenger and his EVA suit. A lander that used 500dV to land and 4200 dV to orbit . . . . . 4700dV with the most efficient engines Metholox engine 375 sec means that you need to get a return rocket of 7 tons on Mars just to hook up to a ID Mars return vehicle . . . . . IOW Musk walks into the coffin at time X, pushes a button, it travels up to orbit and parks next to the return vehicle. He gets out, space walks to the return ship, boards it. The reason why this makes sense more than any of the other concepts is the smaller the return craft, the easier it is to design a return vehicle. A single person lander only needs a few hundred dV which means aero braking is relatively easy (provided they have a place to stay). This return vehicle is at the very limit that a F9 rocket, with the help of a LEO to LMO circulator can provide. That one launch and orbit leg requires one F9 AND is not a ride any of us want to take. The problem is that the dreamy-eyed mars folks are not thinking about just how hard life will be once you leave Earths SOI in the direction of Mars. They keep thinking about USS Enterprise that can warp from point A to B using space ships with nicely decorated personal cabins. Thats why I said a month ago, I though about it for a millisecond and the answer is no-go. Nasa will no-go, I think in the end Space-X will no-go.

Then you haven't been here very long. This design is only useful for a landing site that has already been closely surveyed. The landing struts are too close together relative to the height. Any landing site on Mars can be off by hundreds of meters from that actual landing site. With a grade of 10% or higher this thing is on its side. As for the probes good idea, I made 1/2 scale satellites that can land on a site and gather information (of course they use the faux-pas KSP Ion engines so . . . . ). I can take these small satellites with me. My Currrent mission to Mercury has a combination Satellite based surface scanner and Relay station. Not sure yet whether I have enough dV to make it.

Potatos? Ketchup? seriously people . . . .Can you grow an avocado, mango, grapes (make wine), barley (beer), hops (beer). Some of the paleoanthro folks believe that Ireland and N.England would have been sparcely inhabited if it had not been for the ability to grow barley and ferment barley. Beer and barely malt was survival once upon a time, as you needed something to tide those long winters. Here is how to ask the question. Are you going to bring food animals or not. Answer is true. Model Chicken (they can fly away on Mars) for eggs . . . .cheapest source of animal protein (2-3 eggs per day). Plant crops that are rich in omega-3 fatty acids such as flax-seeds. Diet should be rich in whole grains, supplemented with green leafy vegetables. Answer is False Avacodos and other plant crops rich a diverse array of fats, Crops such as quinua, lentils and legumes as a source of protein. Wheat protein can be extracted to create a protein product, but needs to be modified to reduce its toxicity (gluten has a number of proteins that should not be eaten at high levels when extracted). Coconut is a rich source of C-10- C14 saturated fats that increase body weight and sense of well being. Also peanuts are a good source of protein and fat. In both cases. Lack of fish in the diet could overcome by have an cold climate greenhouse that overexpresses certain omega-3 found in fish. Fermentable crops are those crops that are rich in starch and generally low in protein. Barley, certain wheats, potatos (sho-chu), sweat potato, yucca root (tapioca), . . . . . . The difference between the ISS and Mars is not so much the soil or gravity issue . . . On the ISS they grow food to supplement what is brought frozen or dehydrated on supply ships every few months. On Mars you have to grow just about everything . . . . .See other post . . . . .If we are going by $100,000,000 ( the stated PL for this value is not given, but assume its 18000) for 25,000 kg in LEO then on mars. Then such a craft can deliver 6260 kg to the Martain surface. However of that 6260 you have an engine (277kg) and containment structure (2500kg) which and I propose at least 33% of the weight as some type of aerobraking (2086 kg). This leaves a consumable payload of 1397 kg. Lets add another 30,000,000 for the structure cost to get to mars, target the colony and land. Final cost today for a repeat mission to resupply Mars would be 140,000,000$ for 1400 kg or $100000 per kg sterilized C14 oil (refrigeration not need), 15 dollars cost of coconut oil included. This is the highest energy density food that is safe long term to eat, completely digestable, and most efficiently burned (glucose has nasty biproducts that have to be dealt with such glycosylated proteins as it is an aldehyde . . . . .cause of diabetes). To figure the daily cost we need to know calories in a kg of coconut oil. THere are 7850 [kilo]calories in a liter of coconut oil. The oil has a density of 0.925 translating to 8500 [kilo]calories of oil per kg. Lets say that given the gravity on Mars (and work need to main posture while sitting or standing) and given 1:1 male to female ratio an average human should consume about 2000 calories on Mars. Presupposing that of this 2000 calories 1333 will be derived from coconut oil, how frequently would a colony of 4 people need to be resupplied and at what cost. 8500/(4 x 1333) = number of days colony can survive on kg of coconut oil = 1.594days. $30k/day (cost per human per day . .$7000). How many years can the colony survive on the shipment . . . . .6.0 years. Economically this in not too good on Earth, but in space this is a reasonable cost. Disclaimer here, if the environment is very cold, humans can burn 2 to 3 times of calories per day particularly the oils. So if they are working out of doors in the Martian night, the cost of oil calories goes from 1333 to 3333 [kilo]calories per day. Another argument for using more robots on Mars. Cost reduction strategies. First - for a colony of four, with resupply every 4 years the highest bang for the dollar is going to be in mission conservation. That is to say use proven strategies with guaranteed success. (Noting the failure of many resupply missions to ISS). Colony collapse due to malnutrition brings in magnitude higher human resupply cost. efficient storage. I should make a note about C14 oil which goes along the same logic as metal fuels for Ion drives. C14 oils have all but no vapor pressure at STP and freeze just below room temperature. Thus if the C14 is the sole item ship we can reduce the structural cost of the payload to 0.025 from 0.1 for the food part of the payload (keeping in mind that the ISP is for cryofuels but the cost of storing cryofuels is not included in the weight, I am making the assumption that n the near future this rather simple problem will be overcome). Technically speaking coconut oil can be used as rocket fuel in a duel cycle engine, so cryogenic fuels are only needed in LEO to LMO insertion and aerobraking could be used to get ship to Mars plus 500m above landing elevation. Given this we could probably double the payload to 2600 kg. Given a maximum resupply interval of 4 years only 66% of the payload can be devoted to resupply of other items (such as essential vitamins). Thus as long as you can keep the fat cool (colder than 4'C) you basically can have blocks of fat attached to the hull of the transfer ship mounted on large aluminum screws about a central pole. Any thin solar reflector will suffice to keep the fat frozen in space (sure hope Mars reentry strategy works). This is workable for a Mars resupply mission for most items except foods that need to be eaten fresh, however with -80'C cryogenic storage, no foods technically need to be eaten fresh, not even after 4 years. One storage unit however weighs about 800 pounds and the newest models need servicing every 5 years (however if you allow the use of older CFC's the duty cycle is about 3 times longer). efficient transfer. This is a much more insidious problem. Given that our oil is indefinitely stable (pureC14 will not go rancid like olive oil). We now have the luxury of time and with time our propulsion system variations broaden greatly. Given our transfer cost of to Mars is 3884 of which only 600 is needed to get to Mars from the most eccentric elliptical orbit of Earth. Since ION drives can be used to kick our space craft into such an orbit we can now focus on space craft with efficient engines (but huge solar panels). The basic strategy here is to start at LEO say 150,000 meters. The 3rd stage of the F9 payload is ION drive space craft (lets use magnesium as the fuel since it has low storage cost). About 1/4 of the space craft weight will be solar panels. 1/10th of the weight will be Lithium-ion batteries. The ISP is 5,100 (Exhaust velocity is 5000). One of the advantages of using metals is that there is no need to contain them, magnesium isnt the only metal that can be used and better ISPs might be obtained with graphite or Lithium-Boro-hydride or other solids that do not need pressurized containment. This is important because the aerodynamic shielding required to protect such items is a launch to LEO mass only, and the containment that is used need _only_ be physical and need not be pressurized or potentially structural. An example would be a Carbon coated magnesium nose cone (instead of a carbon-fiber) that is then consumed for ION drive fuel. There are then the dynamic concerns of ION drives. Efficient use of fuel requires the pulsing of engines at pE that then drives the extra-systemic elliptical into an intersect orbit. The problem here is that ION drives cannot produce the output required to pulse once leaving LEO on intercepting transfer orbit and pulse a second time to place the ship in orbit. So we have to examine the benefit of ION drives. 1. Enough dV so that we never have to relaunch - have a repair bot in LOW earth orbit replace the grid and replace fuel, you can also have repair bot in LMO that likewise replaces grids. 2. Engines are very light weight, but they produce little thrust, they typically can operate a few years before maintenance is required. Lets say for a 26000 kg space craft you need dV of lets say 7000 over a year (I will get into this later). Only 15% of the ships transfer and insertion to circularization weight needs to be fuel. So the assumption here is you have ISS2 which is more like a train station than a science station. A transfer ship waits in the station, this ships includes a Mars-brake and land ship and an ID-circulator that travels back and forth between the station and LMO carrying the Brake and land which carries the PL. Lets say the ION drives are active for 1/4th of the trip and inactive over the rest. The F9 rocket transfers 26,000 payload to the transfer ship (replacing drive grids and adding fuel). This means that gross mass is higher how much higher we have to calculate. The minimum amount of thrust is approximately 25N. Seems like a little but its actually alot The drawbacks of ION drive circulators. 1. From the above we need at least 25N of thrust to get us from LEO and a psuedo transfer orbit that adjusts prior to mars SOI intersection to lower insertion and circularization dV (because of low-light and thrust issues). The amount of thrust an ION drive can generate is 2 * efficiency * wattage / Ve = 70.58824 KW. This can be achieved with 2 ION drives weight 50 kg each. So we now have 100kg of ION drive. We also need structure to carry 26000 lbs of fuel and payload, at least 15 percent (lets say another 5 percent to return home). 0.025 x .20 * 26000 = 130 kg of circulating fuel containment structure. Another 20kg for fuel transfer mechanisms. Then we have the srtuctural frame for the landing ship, lets say 0.05 of weight of landing ship. 26000kg - (ID fuel) = 20800 =. 20800 x 0.05 = 1040 kg. Next we add solar panels. This is where we get hit hard. 70 KW at 30% efficiency and considering that such a ship spends its orbit halfway between Earth and Mars (Average(149 Gm, 228 GM) = 188.5 GM. Now we are going to go near future and argue that have to consider that 40Eff solar panel can output 1.26E25 / Osun2 where O is the orbits semimajor axis in nearly solar orbits. Next argument is weight in our near future technology the extra-cylindrical mass per unit area is 0.5kg/m3 for Solar panel surface area. mass = 70/2 * output/m2 The mass of the solar panels is then 12,351 kgs (this is 2 panels 62 meters in radius) . We now have to add vessel structural mass of 0.05% to accommodate the new stresses for a total of 12948, this drops our thrust/kg and increases our power requirement. We also need to add a third engine. The third engine which all-things-being-held-equal approximates the derivative of thrust requirement brings the panel requirement to 18500 kg. This brings total Circulator dry mass to 150 kg of engine mass, 2000kg of structural mass not including structure devoted to Panels, 18500 kg of panel mass ~21000 kg of circulator dry mass (one F9 luanch) noting that the grid weight per 3 35kw drives is trivial (You could actually have a low mass maintenance bot that replaces these in route and improve average efficiency, paying for itself). So now we know what we need on this 50000 Ve (5100 ISP) ION/Solar panel driven circulator (sparing the math). 21000 kg Circulator, 13200 kg of Circulator Fuel, 12800 kg of gross lander mass. The gross lander mass is composed of 1000kg (100 kN) 375 ISP Metholox engine (the circulator stores and conserves liquid oxygen and liquid methane during the trip and loads tanks prior to orbital entry the circulator also provides low pressure ammonium based cooling for any perishable foods on the ship via a solid copper semi hexagon seat that the lander ship sets into via passive heat transfer, temperature is maintained at -55'C). 4268kg of detachable mars aerobrake, 500dV of fuel requires 1193kg of Fuel and tanks, lets say another 91% of the remaining mass is devoted to food. This leave 5700 kg of food from one F9 supply mission to a transfer station in LEO about earth. The variable cost is $15604 per kilogram of food. Utilizing Advanced Transportation as a source of food and soil micro-nutrients Having previously established the daily cost in calories for a 4 year period 66% can come from Oils (C10 to C14). The remainder of calories (666 per day x 4 individuals x 365.25 days/year x 4 years approximates 4 million [kilo]calories) would come largely from proteins of a perishable nature, the reason I say this is that slow carbohydrates are the easiest to grow, nature is very good a producing these (and humans are very good at refining these to fast carbs). Protein is expensive, but it has a dual function since the nitrogenous waste (urine) of a low sodium diet that is filtered produces a R/O decant that when added to compost rapidly becomes usable nitrogen. The compost can come from a combination of inedible plant waste and human feces. Proper containment of the gases (CO2 makes up the overwhelming end produce, but other nitrogenous gases are produced and includes hazardous microbial spores). Protein contains about 8500 usable [kilo]calories per kilogram (Eggs are 100% usable, Collagen is poorly digested). This means we need 470 kg for four years of dehydrated protein. Adding back the 1000 kg amount of Oil needed by 4 individuals for 4 years this brings the total cost of food in grams to 1500 kgrams for a 4 year cycle per 4 individuals. Given we have a payload of 5700 to play with we could add another 11 people. However I would suspect that the additional 4200 kg of PL would be utilized for bringing personal items (clothes, toothbrushes, ipads, feminine products, makeup, first-aid kits and with kids . . . . . . . ). Colonist could for-go luxury items for building materials for expaning there colonies. This might include husbandy kits (for laying hens) and might also include cryogenically preserved eggs for brood stock. Greenhouse expansion kits. Drilling equipment for excavating martian tunnels for the purpose of permanent enclosures. In Situ Manufactoring (includes iron alloy structural framing and aluminum alloy enclosure pressure walls, LED and wire manufactoring) Cotton could be grown for textile production. . . . . . . . . Thus you need at least one, probably two skilled laborers. If the colonies are relatively closely spaced their could be a devision of specialized labor. Reducing the dependency of Earth. This then opens up a third efficiency facilitation: To make that ship capable of hauling 6000 kg and use it to resupply calories to 4 colonies. This really reduces the cost of transportation. Fixed Cost of a Circulator System. The cycle time of a circulator with maintenance lets say is 25 years. (1/4th of the panels) at the current cost the most efficient panels are guessing about 1000$ to $5000 per meter. So lets argue that the circulator has a 5 year cycle time. That roughly comes out to 1/5th of its total life cost per cycle. 21000 Mass to LEO is 64,000,000 million dollars. Then we have to consider the cost of the space station, arguing its completely robotcized but with periodic human repair missions. The transfer windows to Mars can be rather wide for ION drives since they do not burn completely to their target but adjust their orbit to match that of the target as they approach its SOI. So we could have vehicles leaving all the time some going in the direction of Venus then burning up to mars, some taking a more direct orbit. In a duty cycle the station could service 10 colonies on Mars or 10% of the yearly cost of the station being born by a single colony. Assuming a modest size station that last 50 years this breaks down into a few 100,000,000$ per year with 20,000,000 going to the cost of each colony. The transfer ship needs then 100,000,000/25 years or 4,000,000 years of capitalization (assuming no depreciation) with depreciation. The Lander and Payload run 10,000,000 per year. This translates to a total of 34,000,0000 per colony or 8,500,000 per person per year. If the cargo only supplies the caloric needs of the colony and can resupply 4 colonies each 4 year visit then the cost goes down to 2,300,000 per individual per year. The optimal macro colony size is therefore 12 to 15 individuals being resupplies every 4 years from the calories brought on one F9 launch either expendible (15 individuals) or non-expendible (12 individuals). Summary The basic answer to the trivial responses regarding pleasure foods. You grow in your greenhouse that which most greatly reduces your resupply cost. The green leafies are the most expensive because they are mostly water and provide little caloric nutrition and they are simply the easiest to grow and you get the most benefit from eating these fresh. Next you want to grow whole grain crops and complex/carb protein crops. Carbohydrates are 5 times more expensive (As high as 50000$ per individual per day) to ship from Earth relative to purified C14 oil as a major source of calories. But the other part of this is that whole grains are the primary source of dietary omega-6 fatty acids, which have a safe shelf life of only 1 year and go rancid. Therefore the whole grains for two reasons should be grown in-situ. A third reason is that the chaff from grain crops are soil-building compostable materials. Remember those perchlorates in martian soil . . . . .mix that into composting human feces and urine in a chaff waste compost heap (cooking at around 50'C) AND forget about it, in three weeks it will not be of any concern. Need a source of heat in the winter, turn on the compost heap. When mixed with the desalinated components of urine put compost into overdrive, rapidly break down and increase the heat (&CO2) production of the heap. This is not perchlorate bioremediation, such as treating soil with microbes, the bioremedial rate of soil is two orders of magnitude slower than a compost heap, as long as the compost is well mixed and the proper seed of microorganisms are provided the cellulases in the compost drive heat formation and provide an abundance of sugar for microbial growth. So there is no benefit to supplying sugar from Earth if a greenhouse is available on Mars, there are only detriments. That ketchup, take those tomato and onion seed with you and make quick friends with the botonist in the colony. Vinegar in ketchup is slightly higher cost than oil (you will receive glacial acetic acid which you will have to hydrate). Grow tomatoes, remove skins (of course grind, cook and eat), remove seeds, grind cook and eat. The pulp of the tomato is cooked until color changes, added onions, salt (from your urine, btw), and acetic acid, the sugar will be squeezed from cane and dehydrated on an electric stove, the molassis (also edible) removed and sugar crystalized ground and dried. The sugarcane pulp will be growned using a metate to produce a fiber that will be treated with cellulases and fermented with yeast used to make ethanol. The Ethanol will be saved to make return home fuel. The yeast extract will be used to make food thickeners. The oxygen produced by the greenhouse will be saved on site to make pressurized oxygen which is cryogenically concentrated to make return home fuel. Theoretically the landers could be reloaded with fuel, sent back to the ID-circulators and sent back to earth (absent the martian air brakes) but the cost utility of this is not good. Although Potatoes are good there are many other greens in which the whole crop is edible. Change your cravings to things that are coconut flavored . . . . . . Just because I know how to do Martian-life stuff is not a suitable reason for me to want to go there. The first Moron to step into his roboticized martian colony has a world of misery and hard work in front of him. Yes - I have an LED lit greenhouse, make my own compost, know a little about the chemistry of the heap, know how to make soil from sand, . . . . . . .there is a reason why men of old laid down the plow and took to the sword, as to the fact they make fun of farmers trying to squeeze out an existence off the land. The primary reason is for each pound of grain you have to grow 10 pounds of plant, 15 dried pounds considering the roots system. When you consider that the average human needs 2000 [kilo]calories per day. And if we break that down into 1800 calories per dried kg of grain translating into 1.1 kg/day, this means that the average human needs to generating about 50 lbs on living biomass per day just to sustain himself. The botonist in a colony of 4 individuals 200 lbs of day of living biomass. After you're done harvesting your crop you need to compost about 20-30 lbs of that green per day. Doesn't seem like much until you realize that the Heap needs to be turned every few days (grab that shovel) and it would take 4 or so weeks to get into its rest state. So that at times youre daily chore is moving around a ton (on mars 600 lbs) of compost on a routine basis. After that you want to mix the compost into the maintenance substrate which is 4 times the weight of the compost. That rocket ship your fueling, you get about 1 part ethanol for every 20 parts of cane chaff you grind to a pulp. You are going to be grinding for years to get enough pulp to make the alcohol to return back to Earth. But not only this, you will put on that EnvSuit and go out and chisel rocks or fix drill bot that are hammer a tunnel into martian sandstone so that you can build housing and greenhouses that are safe from Martian faux-pas (such as cosmic radiation) and that is going to be the substate that you take back home and grind into soil. You are not ready for living on Mars. When you can farm and prepare all what you eat with your own hands, then. . . . . . .

I say its completely lifeless spare the odd bacteria living in a gravitationally heated underground crevace 10 to 20 miles underground.

^^^^ and many forms of them, some are detected in the fossil record. The problem with paleontology is that it geologic events tends to preserve massive and bony things, things that burrow deep in the mud, and of course shell builders. Imagine if you are big soft-fleshy thing in the ediacaran and something with teeth evolves. Now imagine the big soft fleshy things grow in a scalar manner from tiny soft-fleshy things to big ones. The first thing that comes along with the tiniest teeth can wipe them all out. When that guy evolves, he will not even show up to a scientist living in the ediacaran, let alone paleontologist. With predator prey ratios of today it would take an awful lot of fossils to find the one smoking gun. In the case where a tiny egg-biter is basically eating all the progeny before they mature such a predator would be invisible in the fossil record. The prime example of replacement is Lystrosaurids represent 95% of fossils from the southern hemisphere after the Permain-Triassic extinction event, within 15 million years they are all gone. No extinction event required. The critical event in life on earth is not neobiogenesis, this is probably common in the Universe and may have happened on earth on multiple occasions. The formation of cyanobacteria and diversification of Archea, particular the development of commensal organisms that live inside a single lipid bilayer paves the way for compartmentalization of functions. Cyanobacterium do this to the extreme, they compartmentalize nitrogen fixation (which is extremely toxic process to most life forms) into a compartment that can basically be jettisoned when adequate nitrogen is available. Think of where life on earth would be without that one advantage. https://en.wikipedia.org/wiki/Diazotroph So Ediacarans may get wiped, lystrosaurids may get wiped, but cyanobacterium and Archea barely notice.

Agreeing with much of what you say. During tantrums the spectra does shift somewhat, and it has been theorized that these tantrums can cause close orbiting planets to be degassed. The problem with excessive unprotected UV and X-radiation is in the lighter elements (Hydrogen, helium) Xrays in particular are known to exert nuclear force (it is the xradiation in an H-bomb that compresses the nucleus of the bomb allowing detonation with a much lower critical mass) of fissile material. It is believed that the exposure of Venus to higher levels of solar radiation depleted the atmosphere of hydrogen, water, some carbon and oxygen until it was stabilized by sulfate. The absorption spectrum for hydrogen has strong and weak bands. UV hitting a strong band can kick off an electron cause the proton to repel other protons. If you kick the electron off a sulfate molecule or hit it with an X-ray its not going to react nearly as strongly (in terms of acceleration) as a hydrogen or helium might. The thing that we have to remember that in the early days of a potentially habitable planet the hydrogen is in many forms, hydrogen, methane, ammonia, etc. In a two step process the hydrogen can be kicked from the molecule and then kicked from the atmosphere of the planet by ionization and then interaction with magnetic storms or being pummeled by xrays. This is a problem for stars closer to proxima centuari than venus is to the sun. For most small stars the habitable zone is just such close to its star and thus the habitable zone of most M class stars would be in the zone were flares could strip the atmosphere of its lightest gases.

Given 1 human. Required space 2 meters by 1 meter by 1/2 meter. Biological weight about .08 tons (naked) Oxygen intake per year 0.785 tons Oil equivilent in weight Steric Acid (the most common fat and most compact energy source in human body) 0.285 tons Minimum capsule size for storing oxygen and food and one human. 2 tons. (this includes physical housing, airlocks, waste water recycling/AC/heating solar panels) <---- very conservative probably 10 times higher. Minimum coffin that can keep human alive for one year 3.5 tons in weight including weight of human. Shipping one coffinized human to mars from LEO and back into LMO before docking with return vessel. 91 tons In LEO (using 5760 dV to transfer and circularize at mars, 5250dV to land on mars and return to orbit) using Metholox (ISP = 375 although the long term storage method for oxygen is not included in weight). Sending another vessel to dock with first vessel in orbit and return human to earth, 50 tons. Getting 150 tons to orbit ~ 7.5 Falcon 9 launches one BFR (vapor rocketry). The lunar module weighed 16.2 tons and housed 2 individuals for a few days. 8487 of that was devoted to fuel. Thus 8 tons was divided between 2 humans or 4 tons each. This was for a stay of maximum of a week and was not designed to break against a martian atmosphere. So a more reliable estimate of the amount of mass required for structure and other components is 10 tons which means to get a human to mars and return him back to earth would require 1kT/human of payload in LEO. You fulfill Elon's dream of dying on Mars for about 0.5kT since you only need to feed him for 8 months. A Nasa Style mission to Mars (3 individuals including one that stays in orbit) Probably 2.5kT in low earth orbit. The non-expendible is $62,000,000/15.1t in LEO translates to 4.1 million dollars per ton at present cost. The cost of sending 1 man to mars and getting him off 4.1 billion dollars, slightly less per person to send 3 to Mars, 2 down and 1 in orbit. around 10 billion dollars. This does not include the research and development costs or the cost to fabricate the parts required to get their. My guess is such an venture would run 0.2 trillion dollars or so. The cost of sending a 1000 people to Mars (assuming the pooped filled ships are not dumped in the pacific), probably 3 trillion dollars at nominal cost basis. Note a previous post that if you create a highly eccentric orbit around earth the transfer cost to mars is 2460 m/s, but requires a refueler that essentially uses the energy require to reach GTO and transfers fuel before alternings its course to crash back into earth. If you launch an essentially empty ship into Orbit, you can refuel in LEO, then create an eccentric orbit, refuel again and transfer occupant before burning to Mars. In this scenario you decouple a fuel tank (or in Apollo style, a pilot and back home fuel) in Mars orbit then you land collect sample, connect with fuel ship where pilot joins landing crew, decouples and burns back to Earth, 9 months later they arrive at home. In this fashion you can break the launches up into at least 4. The Lander assembly, the orbit assembly, LEO fuel to eccentric orbit, eccentric orbit fuel to Mars and return. For such a 3 man mission you would have on average launch 625t of LEO payload. The BFR is 150t at LEO, which means that alot more work needs to be done. Again, this assumes that you cut the Mars landing dV cost from 4000-5000 to 500 or so by some 'handwaving' means. Without a defined means of cutting the landing dV the assume weight of fuel for mass of payload is 9.17 to 1 and thus a lunar module size lander would need 100t of fuel (substantially larger engines and fuel tank carrying capacity). As long as Space X is talking about rockets in the 150t range . . . . . . . .we are dreaming about Mars. When they start testing structures and engines with Payloads in the 1kT magnitude, I'll start taking those Mars-land-die dreams seriously. As for Me, I got 1.063 kT into LEO today (launch Mass 25kT). But im going to send Kelon Kusk to Mercury, because we know there is icey-water there! But then Kelon is a Kebal and he can live indefinitely in a 0.7t landing craft. They don't need food or water, they don't poop or pee so . . . . . . . Looking at my counts it took RS-68A 22 + 28 + 48 engines, an additional liquid fueled two engine boosters (24)

The ice on mars is largely frozen carbon dioxide. The water on mars is 100% brine that crystalizes in extreme cold and flows under sunlight or geothermal heating. A comparable water source would be a salt flat on the edge of the dead sea.

That is a useless, there is not a chance that it would work. If the breaking forces are as great as they say they could never turn a wing sideways. Second wings that create lift also create drag. So on launch want your engines to provide lift, not the wings, they provide more weight to carry up. As the speed increases and they begin to create dynamic force the only force you want comes from the aft section of the wing, but either the wing is creating drag on the fore or or lift (pushing the craft over). Basic physics. The more SpaceX throws out baseless concept material the more I distrust their opines about reaching Mars. Please stop distributing misinformation. Plenty is relative. The Pacific Ocean has plenty of salted-up freshwater.

If you are using space to bring in an army, seriously don't wast the time on arming men, remote warfare is the future of warfare. We have soldiers in Iraq and Syria to run computers and feed info to the locals, but the eyes in the sky is where the business is being done. If you take a look at these, civilians evacuate . . . . . . .any number of modern wave-form weapons and automated robots can be used to basically 'bomb' the holdouts.

Lots of trees have died to make paper plans for space ships that never went anywhere. If someone is telling me they are devoting much of their dev staff to work on the plans, I would say what they are showing me at present is only a concept, one in which they do no know will work or not. You couldn't get me stuck on a ship like that for 5 to 7 months. Ahh and I have been practicing my Mars Aerobraking stuff. I have tried several methods. Again I am using the super efficient RL-10B engines, the problem is to get back in orbit you need 4300 dV of fuel, and that is not easy to land, you'de need like 5500 to land and 4300 to return. Since wings get trashed before landing that bit of weight can be ingored except as a transfer cost. I have managed to get landings down to 400 dV, using RCS thrusters during decent to control position and augment lift. But again RL10b-2 is fantasy engine. How do you get the hydrogen to Mars, and of course the return launch window is a long way from the landing timeframes which means efficient cryogenic storage is expensive. This may be why Musk is focused on Methane. But he still has to liquify it and keep it and oxygen liquified. The other problem with RL10b uses an ablative nozzle that has a finite duty cycle, this speaks major problems since for any mars landing and return mission you need a very efficient engine, low TWR and has an infinite duty cycle. You gotto have alot (alot more than they show) of wing to get adequate lift to stay aloft long enough to slow down. The vehicle I had the best results with look like a cross between the red-baron tri-wing and the Wright flyer. It took me down to 500 m/s in which I drop the wings and landed just like on the Mun. Coming out of Mars those wings do not offer any advantage. I managed to put 500T at a = 1900 km LEO with the 68As (a bucket load of them, I'm working to get a single palyoad of 1 KT - I figure that is what it would take to make a manned - not kerbaled, but human size crew compartment landing on Mercury). Its not hard but you need a scale of rocket a magnitude larger and more powerful than the current falcon or falcon-heavy. This discussion about putting a 150T load in LEO for the current cost of an F9 . . . . nope. If I were space X I would be dreaming about putting a factory in MEO first, a place where you can finish off a Martian landing vessel. The mass of the aerobrakes great (increaesed total mass by 40%) but they are way to bulky to accelerate through earths atmosphere to 7850 m/s.

With regard to F9 and F9 heavy, no. But with regard to ITS, it is a bit snake-oily. They had an imagine of it passing by Saturn . . . .seriously . . . . . 3 year journey to Saturn for a flyby.

Firefox will not load, says threat to computer embedded in the web site (maybe sniffer application). They can give NASA a public funding arm (like PBS) in which people contribute to the future space projects they want.

The major reason for ISS is to study the effects of space on humans. As Einstien pointed out, at the microscopic scale you can not distinquish gravitation from centripedal acceleration. A body in orbit (inertial reference frame) may be seen to be defining gravitation, but from relativistic approach is a body whose direction of motion is following an isoquant in space-time (just as if it was traveling along a strait line in deep space). Centripedal acceleration or a person standing on the earth both represent deviations from the isoquant and thus create observed accelerations. In the case of relativistic gravity, it is the earth pushing up on your feet, that would otherwise be on a eccentric (nearly 1 orbital path) or in the case of a centrifuge the outside metal of the centrifuge which is pushing up on your feet wanting to travel along a strait path. Theoretically centrifugation and gravitation produce the same on the microscopic scale. What is the point of studying what you can study on Earth. Which is, by he way, the twins study did. One twin stayed on earth and the other spent almost a year in space. The only real reason for have a human centrifuge on the ISS is to test the mechanics and engineering for the device. Even if you were going to test humans in it you would have to have one twin stay in the device and one stay out of the device.

Oh, boy . . . . . what a stretch. The leaf of a plant 1 mm thick and 1 mm from the ground can capture hv emitted from the sun, most is turned to reflected light and heat, a very tiny portion is used to reduced a nucleotide which is then used to make a simple sugar which is then elongated to form glucose. This is what drives the ordering of life, alot of disordering of hv and a little ordering of chemistry. From the point of view of the light (which is ageless) disordering light a millimeter away from the next reflector or 13.8 billion light years away does not alter the entropy argument, disordering the light in other forms of energy which degrade into heat is energetically favorable. And if you think about pure hv is converted into the bond formation energies of a seeming randomly assortment of biological compounds. If you were going to do the energy math: hv (200 to 800 nm) ---------> reflected green light + far infrared hv + H20(l)-> H20(g) + Air(T -> T+) + C-H bond energy + bond energies in CO2, H20 and SO42- to C-C bond energy +C=C bond energy + C-N bond energy + C=N bond energy + C-S bond energy + P-O-P + bond energy + C-O bond energy . . . . . . . . . At the lowest levels of examination life seems to favor entropy.