Let's Design a Settlement for Mars!

tfrederick9 · Mar 21, 2005

"Good question, also how much do we rely on governmental comm/tracking infrastructure here on Earth? Are there currently any other options than NASA/DSN? " As far as I know NASA has the only DSN out there that functions. I'm not sure what the Russians used for thier Venus mission, et el. I would suggest that "we" build our own DSN site, as the last number I recall had DSN at several $1000s per minute of coverage. I would also suggest that provided comm and MPS are in orbit around Mars, that we sell the ability to use them to NASA, JAXA, ESA and whom ever else wants it. You could even do Thermite welding if it came to that, all you need it rust and aluminium.

dan_casale · Mar 21, 2005

Arobie: Sorry, I didn't mean to imply anything wrong with your post. I just wanted a more aggressive and detailed post. Thanks for the reasoning behind the two landers. I can't decide if it is better to land all the equipment as one big lander, individual landers or something in between. Having more landers means less payload capacity, but having more landers means less equipment to replace if a lander fails. We aren't getting ahead of ourselves, we are all working on different parts of the same plan. So what do you think we should outline next?

spacester · Mar 21, 2005

I'm sorry guys, I'm just too busy right now with that darn real life stuff. I'll be back later . . . maybe tonight . . . Martian bandwidth might be the first priority, I was waiting for someone to bring that up. I'll try to get this thread back on track ASAP . . . I know what to do but it's not quick . . . sorry . . . <div class="Discussion_UserSignature"> </div>

arobie · Mar 21, 2005

Dan_Casale, Oh, you didn't imply anything wrong with my post. I didn't even get that vibe. <img src="/images/icons/laugh.gif" /> I appreciated your comments, and agree with you for the most part of what you said we should send. There is alot of stuff, and alot of it we have not put thought to yet. With that breakdown post, I was just trying to put the big basic parts of Spacester's plan into ships. The list of ships needed probably will grow, although we don't want it to grow too much. We need to try to be conservative, but what we need to take...we will need to take. The reason I think we are getting ahead of ourselves is because while typing up and thinking up my breakdown, there were alot of uncertanties, mostly dealing with mass. We have not designed the interplanetary booster yet and as so have not given ourselves definitive mass ranges, nor do we know how big our equipment will have to be, nor do we know how big of a crew we have to support on transit time and in the beginning of the settlement. It is hard to get too detailed not knowing our mass constraints...not knowing just how much we can fit on top of our booster and just how much we have to send altogether. As a result, my breakdowns will most likely change as we find out that we cannot fit everything allocated or as we find that we can add more. It is too hard to get too detailed without knowing how much we can send at a time, but what you listed is important. I may not know if they could fit on the ships already listed or if we need another, but it's nice to already have listed what we will need to add when we conclusively breakdown our payloads into ships after we have worked through a few other things first. As to what I think we should outline next, I believe we need to work on our interplanatery booster. We should flesh that out. It will decide how much we can sent to Mars on one ship and will so decide how many ships we need to send. But I'm waiting for

JonClarke · Mar 21, 2005

There are lots of deep space tracking stations out there. NASA has three, ESA two, the Russians two (plus several mothballed ships that could be reactivated if need be), the Chinese four, plus several ships. I suspect that the Japanese and Indians would have at least one each as well. Jon <div class="Discussion_UserSignature"> Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars Arthur Clarke </div>

dan_casale · Mar 22, 2005

Arobie, I thought that ground had been covered, but I am happy to summarize/expand: Currently existing launch technology: Delta IV heavy - 10,843Kg to GTO - 5 meter faring - no info on length of payload. Atlas-V-551 - 8,200Kg to GTO - 5 meter faring - no info on length limitations. Shuttle - 28,800Kg to LEO - cargo bay 15x60 feet - Unknown amount (20,000?) to GTO. Ariane 5 - 8,000Kg to GTO - 5 meter faring (assumed) - no length info. No info on Russian launch systems. Near future: (This requires modifications to an existing launch system) STS - Shuttle-C - 79,256Kg to 400Km - 8.4 meter - No length info - 34,380Kg cargo container/w reuseable engine pod STS - ET - propellent only launch - approx 113,000Kg of propellents and equipment to maintain LH2. STS - Shuttle - passenger bus - Cargo bay is modified to carry Mars crew. STS - ET wet launch. ET is modified to hold equipment or prefab as cargo container. Opened in GTO and stuffed full of equipment for the trip to Mars. Future: Super heavy launch vehicle Crew transport vehicle Large ION engine powered by solar or Nuclear Crew information: If we calculate the consumables on a per person basis then we can make progress without knowing how large the final crew will be or how long the mission will be. For example: O2 requirements - 1323/Liters of gasous O2 per day. Water: 2 Liters/day drinking 2 liters/day food prep/rehydration 2 Liters/day Hygine 20 liters/week laundry 20 liters/week showers Food: This is a nice formula - Caloric requirements are determined by the National Research Council formula for basal energy expenditure (BEE). For women, BEE = 655 + (9.6 x W) + (1.7 x H) - (4.7 x A), and for men, BEE = 66 + (13.7 x W) + (5 x H) - (6.8 x A), where W = weight in kilograms, H = height in centimeters, and A = age in years.

spacester · Mar 23, 2005

To begin getting a handle on this vast undertaking, I organize my thoughts in terms of several different groups of three. There are three categories of expenses (capital expenditures): Transportation Hardware Operations Transportation is broken into these modes: Launch to LEO Interplanetary (orbital) Surface operations There are three classes of Hardware: Vehicles Habitats Factories Operations are very much undetermined. By way of beginning to lay a foundation for explaining my financing plan, to simplify discussion, I will keep everything in those groups of three. For Hardware, I’m hoping we can break them into sub-classes and develop an overall list. The transportation modes call for vehicles quite different from each other. There are three sources of financing: Not Telling Yet <img src="/images/icons/laugh.gif" /> The starting point for devising the finance strategy was to adopt the old saw: “How do you eat an elephant?” (Now I love pachyderms, don’t get me wrong. It’s just an old joke, OK?) Answer: one bite at a time! It’s just a metaphor. Now if a tribe comes across a freshly dead, healthy elephant, it represents an opportunity for feasting, But to get the job done in the time allotted, it’s wise to spread the meat out to fellow tribes. If there’re several elephants, maybe you can feed more than one clan. Financing this settlement plan is like dealing with a lot of dead elephants. The cost needs to be spread out over a wide support base. In fact, these elephants are so huge we might as well treat them as Oliphants (“Big as a house, grey as a mouse”). I want to talk about getting enough support to deal with three Middle-Earth sized hunks of elephant flesh. It will take three clans to deal with it. The three clans are going to finance the three capital expenditures: Transportation, Hardware and Operations. <div class="Discussion_UserSignature"> </div>

spacester · Mar 23, 2005

I want to talk about all the great points made since my last post, but that will have to wait. I feel a special need to respond to Dan’s excellent summary, that’s a big help. I need to be careful in saying I 100% agree with something, so I’m forced to quibble, and that’s all the following is, quibbling. (What a cool word.) The near future could very well include a HLV (defined as much bigger than the biggest current EELV) that is not a shuttle derivative. SpaceX, for one, could do it and I predict they will have a competitor within five years. The water and food numbers are great to have, I look forward to putting them to use. The nine life support systems are a great, an excellent, starting point. But I want to reorganize it a bit to fit our way of operating. I see five utilities (1, 2, 3, 8, 9), three operation activities (4, 5, 6) and Transportation. The utilities will be provided by hardware, and there we have it sorted into three expense categories. Categories, classes and modes. Categories of Expenses. Classes of Hardware. Modes of Transportation. So that’s some organizational structure to work with. <div class="Discussion_UserSignature"> </div>

spacester · Mar 23, 2005

But what should we talk about, you may be asking. Well, I’ve hinted at the financing plan. I’m going to introduce it slowly, but it’s time to actually begin the process of doing so. To this end, we need to flesh out the list of hardware, but we’ve seen that we’re not ready. So what’s missing? Two things, I think; a timeline of some sort that relates to the availability of financing. I don’t plan on coming up with the whole wad of cash up front.

The second thing is an agreement on mass, just as Arobie pointed out. The way out of this dilemma is to choose a crew size. So I’ll just make an executive decision and pick a number. 28. There will be four teams of seven, each team capable of performing any operational task in the settlement. Over time they will tend to specialize a bit, but the idea is to have a diverse array of talent attending to any given problem. The timeline problem is a natural outgrowth of the fact that our aim is to settle, and that means we need maximum flexibility so that we can react to our environment and get better at living there. More on that later, for now, we can lay out which items go on which cycle as a benchmark, but what we’re really laying out is the progression of technology and how they need to coordinate. What we really need to do is lay out best case worst case and most likely case. <div class="Discussion_UserSignature"> </div>

spacester · Mar 23, 2005

So there we have it. We will settle Mars in groups of 28. (At least, that’s the number to use pending arguments to the contrary) That’s a very big habitat. Can we launch our second stage habitat on Falcon V in five launches? One launch each for two large inflatable habitats, one launch each for two service modules and another for the hub and truss. That doesn’t count the launches to provision it, which would be shipped by the most economic method for that commodity. Do we need four habitats to house 28 people? It could be done, probably 10 launches at least. The key to an economic design will be to minimize manned orbital assembly operations; EVAs to hook stuff up will be too expensive to do often. I’ve got a design concept in mind to address that, but two habitats would be much better than four. The pair of inflatables would be at opposite ends of a long triangular cross-braced truss. Two trusses actually, with a hub in the middle. The hub is the thrust point for the Interplanetary Booster, which pushes the assembly to Mars via the hub. The truss is stabilized against bending by compressive struts attached to the aft end of the Booster. Also, on the other side of the hub would be a large canister serving as provisions storehouse, which would have tension struts to the truss for additional stiffness, needed mostly for deltaV events, but also making the structure very solid. So the configuration is a long truss with a hub in the middle and big habitats at each end, like a baton twirler’s baton. There would be two big cans attached to the hub (cargo and booster), and the whole thing would rotate around the centers of the big cans and the hub. The booster would inject to Mars transfer orbit from LEO with the assembly not spinning. Spin-up and spin-down energy is surprisingly small, I’ve done the math before. Shortly after departure, the ship is slowly spun up to the chosen rpms, and the assembly spins like a top all the way <div class="Discussion_UserSignature"> </div>

spacester · Mar 23, 2005

One last post before bed after re-reading the latest posts, just hitting the high points . . . Repair is very important. I'm hoping that the whole settlement philosophy will lead to higher reliability and easier maintainability through a design process that keeps those goals in mind at all times. I agree with tfrederick that we should set up our own communications infrastructure and sell the bandwidth to everyone else with activities at Mars. The DSN network almost certainly does not have excess capacity for the likes of us. Thanks for the clarification on hydrazine and especially for the processes needed to make it. So it looks like the propellant system of choice is CH4 / O2 Do we need to bother with the monopropellant? What about hydrazine-powered internal combustion engines for electricity generation? Iron and steel making is very attractive, but we can’t pretend that we’ll have the capability to make complex equipment (not that anyone suggested such). Maybe welded frames for the installation of high-tech equipment, habitat reinforcement, railroad iron, etc. I would say steel making is low priority for critical path development, but high priority in technologies to develop during the first cycles. I’ll get back to the first piece of equipment question later . . . Signing out . . . <div class="Discussion_UserSignature"> </div>

JonClarke · Mar 23, 2005

Elecrity generation CO-02 and XCH4-O2 can both run fuel cells. Or bruned in an APU. For cold gas micropropellant I suggest use either compressed gas, either nictrogen or CO2, for hot gas micropropellant, decomposition of hydrogen peroxide. Incidently argon is relatively common (2%) in the Martian atmosphere and is a reasonable propellant for ion drives. Because the masses needed are relatively small it could be extracted by simple fractional distillation from the atmosphere and lifted into orbit quite efficiently, if needed. Jon <div class="Discussion_UserSignature"> Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars Arthur Clarke </div>

jhoblik · Mar 23, 2005

We have to think about all equipment to support us during a mission as easy as could be. Easy means also easy to fix it. Looks like that Mars have accessible resources of ice. If this is a case, I suggest to build all our engine design around LH2 and LOX propellant architecture. Electrolysis is easy method, that even in classroom with limited tools could be demonstrated. In both environment on Mars and interplanetary space we face problem how to store LOX and LH2 in form of liquid. My suggestion is not to store fuel in that form, but in a form of ice. Mars ISRU unit will heat up ice and collect in easy storage in a form of ice. LOX and LOH will be generated just before departure from Mars and people will be able to fix any problem with fuel production. If we know that we have enough ice, collected before landing, we will have very low risk that we will be not able to produce LOX and LOH, because unit will be very easy to repair. For interplanetary mission we face also problem to store H2 and O in liquid form for a long time. If we save our fuel in a form of ice It will drastically reduce requirement for storage tank, it has to just prevent ice to sublimate to space. In this form could be store for years without special device. At the moment of departure from Earth/Mars, easy device like heater heat up ice and through electrolysis create liquid LH2 and LOX . Fuel could be use immediately to propel ship. Rocket engine will be smaller, trust will lower(depends on capacity electrolysis and liquidation unit), instead of trust for minutes, we will turn on engine for days. It will delay our travel between Earth and Mars by couple days, but related to the whole trip it will be insignificantly. Fuel for our interplanetary mission could be also deliver to rockets that will be launch to orbit. Almost every launch capacity of rocket launch exceeded weight of payload. We could ask to bring to space water in form of ice. On Earth orbit

arobie · Mar 23, 2005

Dan_Casale, Thank you and excellent post. I agree with Spacester in that I also think we will see a HLV in the near future. The commercialization of space is rolling along now and SpaceX has shown interest in and hinted at the development of a HLV after the Falcon I and Falcon V. The Big eff'in Rocket...or BFR if you prefer the acronym. Wouldn't the STS derivatives be hugely expensive? The crew information is excellent. After some research and thanks to an Online Conversion Program, I was able to play with the numbers and convert the data to mass measurments instead of just volume measurments. I also converted your gaseous oxygen into LOX. Before we get to the numbers, I showed my work so that if anyone would like to see what I did, they may. The important figures are in italics or under the bold sections. First the oxygen: 1323 gaseous liters per person per day According to this website: 1 liter LOX = 30.4 cubic feet gaseous oxygen = 860.83214 liters gaseous oxygen 1323 gaseous liters / 860.8 = 1.536 liters LOX 1.536 liters of LOX is required for one person for one day. And according to this website: 100 lb of LOX = 33,756 liters gaseous O2 100 lb = 45.359 kilograms 33756 liters gaseous O2 / 860.8 = 39.213 liters LOX 39.213 liters LOX = 45.359 kilograms LOX 45.359 kilograms LOX / 39.213 liters LOX = 1.156 kilograms of LOX for ever liter of LOX 1 liter LOX = 1.156 kilograms Dan_Casale's number for LOX kg/liter = 1.138 kg/liter 1.536 * 1.156 = 1.778 kilograms per person per day 1.778 kilograms of LOX is required for one person for one day So LOX for 28 people:

tfrederick9 · Mar 23, 2005

I think the hub that spacestar is using for the interplanetary transfer is something we might want to consider reusing. It would take a few mission, but after say 5 trips to Mars, you wouldn't have to launch anymore of them. Its a minor cost saving. Also, I think reaction wheels would do just fine to spin the hub up, they'd be there for ACS control anyway, we should use them.

scottb50 · Mar 23, 2005

I've been saying the same thing on this thread and on the original Mars mission thread. Except without the ice part, I think liquid water would be a lot simpler and useful. Hydrogen/Oxygen yields the highest ISP of any chemical fuel and as such would require the least overall volume of propellant. A considerable amount would have to be carried anyway. Consistant propullsion technology will simplify operation considerably and there are a number of cases where high pressure gas could be used, thrusters and other low power application. When needed LH and LOX can be provided without long term storage consideration, further simplifying operation. Until we actually find water on Mars or the Moon we could easily provide gasses or LH and LOX from orbit for surface use. Once found water separation equipment could be used on the surface and water sent into orbit to power return vehicles, greatly increasing the efficiency of supply missions. <div class="Discussion_UserSignature"> </div>

dan_casale · Mar 24, 2005

Arobie: Good research! Your LOX weight is a little bit higher than what I get from the shuttle ET page. http://spaceflight.nasa.gov/shuttle/reference/basics/et/index.html = 1.1384105727913491314600371901666 Kg/Liter So Lets use your figure, then if our mission ends up a little light we will be in great shape. />I agree with Spacester in that I also think we will see a HLV in the near future. < (A BFR is better than an Little FR.) While this may be true, we don't have any specs about its capabilities. With out specs, all our plans are just pie-in-the-sky guesses. I'm trying not to take that route. />Wouldn't the STS derivatives be hugely expensive?< I saw a figure once that the Shuttle-C deriviative was $1 billion. I would suspect that in reality it could be done for much less. An propellent only launch would require modifications to the ET to provide xyz-axis control. Additionally the LOX/LH2 Engine's need to be moved to the bottom of the tank. I'm going to also assume this will be about $1 billion to design. I would propose we replace the SSME's with less expensive expendable, multiple restart capabile (RL10?) engines. The Wet launch ET's will also be a custom project and therefor be expensive. I think we could use a figure that is twice the cost of a current ET. The shuttle as a passenger bus, converts the cargo bay to a passenger area by using an inflatable habitat with seats. The limit is cargo capacity of the shuttle at 28,000Kg (1000Kg/person). If I had to guess, I would say this could be done for about $500 million. One last thing. />82 liters or 81.999 kilograms of H2O per week.< *laughing* If I remember correctly, water is the basis of liters to Kg therefor 1 liter = 1 Kg, so your calculation is off by .1 grams. : /> Spacester: (No elephants or

arobie · Mar 24, 2005

Dan_Casale, I'de prefer we use the number calculated using Nasa data. It's bound to be much more accurate than my number. I was looking for something just like that, but didn't find anything that easy. The numbers I based my calcs off of were probably not the most accurate, and I had to convert them to other measurments a few time before I got what we needed. The Nasa numbers are cut and dry and definitely more accurate than mine. The space shuttle sounds expensive, but I agree that we want to base our settlement on reality instead of quesses. About the water and it's weight....LMAO! I didn't know that kilograms were based off of the weight of a liter of water, nor did I notice how close those numbers where. My real number for the weight of 82 liters of water was 81.99999999315676. I wasn't off by much. <img src="/images/icons/laugh.gif" /> Now my second number for water was way off. I don't know what I did to figure that weight so far off. I'm going to edit the above post to fix those numbers. I'm also going to add calculations for LOX weight using your number to the above post. Thank you for the comments and your own research. <img src="/images/icons/smile.gif" />

tfrederick9 · Mar 24, 2005

Dan_Castle, That was what I was thinking I just had a brain freeze and couldn't remember the name. In this case the cycler seems like the ideal long term transport system. The shielding on Mars I think should be kept as simple as possible. The idea of having LH2 so close to the hab bothers me, mainly because othe temps involved. I imagine the habs will need heating rather than cooling. I would say we just use the Mars regolith and just cover the habs with it. From what I can find on it, regolith isn't the best material from a shielding stand point. But from our stand point it may be the best because all we have to do is something half bury the habs and cover with regolith. Just an idea, the LH2 is better at shielding. I'm just trying to think of the easiest thing for the first people to arrive there to get up and running ASAP.

arobie · Mar 24, 2005

Hi Spacester, For Hardware, I’m hoping we can break them into sub-classes and develop an overall list. Well then, here's a proposal of just that for you. <img src="/images/icons/smile.gif" /> *One thing before you get there: Classes are broken down into orders and orders are broken down into into families. Classes - Orders - Families The Three classes of Hardware: ----A)Vehicles Class -----------1)Interplanetary Spaceship Order -------------------a)Manned Family -------------------b)Unmanned Family -----------2)Orbital Spacecraft Order -------------------a)Reprop Family -------------------b)Crew/Supplies Orbit to Surface Family -------------------c)Unmanned Supplies Orbit to Surface Family -----------3)Surface Craft Order -------------------a)Rovers Family -------------------b)Hoppers Family -------------------c)Surface Automobiles Family ----B)Habitats Class -----------1)Test Habitat Order -------------------a)Undecided Families -----------2)Space Habitat Order -------------------a)Transit habitat Family -------------------b)Orbital habitat Family -----------3)Surface Habitat Order -------------------a)Converted Propellant Tank Family -------------------b)Inflatable Family ----C)Factories Class -----------1)ISRU Order -------------------a)Propellant Production Family -------------------b)Iron Production Family -----------2)Food Production Order -------------------a)Hydroponics Family -----------3)Machine Shop Order -------------------a)Repairs Shop family So there's a hardware breakup into subclasses. It's open for discussion and modification. As I said, I broke the three classes of hardware up into orders and those orders into families. Now the families can be broken up into genera (plural for genus), which is a next step toward fleshing out a hardwa

spacester · Mar 24, 2005

My strategy is not the same thing as Dr. Aldrin’s (et al) cyclers. His cyclers do not get captured in planetary orbit, they do a swing-by maneuver. The problem I have with that is: you’re on your own as far as the dV to actually arrive at your destination. The big fancy cycler got me to Mars, but I have the entire burden of orbital insertion to deal with on the separated stage I’m taking to LMO. My plan has the propulsion stage do its job at both ends of the trajectory, and then cycle around for the next job. It gets you into a high orbit where you can take your time dropping the second stage down to low orbit. The booster stays as high in the gravity well as we can, considering other factors. It is true that we will be spending more dV that way, but only if you are looking at it from a specific energy standpoint. IOW, IMO when you do the actual mass budget for my plan vs. Cyclers, this strategy spends less total propellant. Cyclers are a technology for a more mature space faring society IMO, they are not the way to go about getting established. The problem with liquid Hydrogen is storage. Or lack thereof.

It simply leaks away, no matter what you try to do to stop it. Solving this problem is an unnecessary distraction, let somebody else do it and we’ll shift to LH2 when that tech is ready. Generating LH2 on the way to Mars is no way to run a spaceline. You’ve got to have assured dV capability to be able to do everything you need to do to get back, before you ever leave in the first place. I also question if LH2 can be generated at a fast enough rate with solar power to enable “gas and go” operations. Propellant: Kerosene/LOX if Earth derived, CH4/LOX if Martian derived. This is the baseline propulsion I’ll be working with until such time as I see some solid numbers refuting the above logic. It is noted that LH2 tanks will be very large, which is attractive from a habitat conversion standpoint, so if the storage proble <div class="Discussion_UserSignature"> </div>

tap_sa · Mar 25, 2005

" I didn't know that kilograms were based off of the weight of a liter of water" Because it's not. Well, it was before 1889 but then it was realized that the litre-of-water mass depends on density which depends on pressure which depends on mass, circular d'oh. The idea of 'electrolysis-rocket' is interesting. Hydrogen releases about 140MJ/kg of energy when burned, efficiency of ordinary electrolysis is about 70% so you need ~200MJ of energy to get that kilogram of hydrogen (and eight kilograms of oxygen) from nine kilograms of water. To get one kg of hydrogen per second 200MW of electricy is needed, either a small nuclear reactor or large solar panel. Both are difficult options but maybe we don't need the hydrogen that quick. 2MW, 10 grams of H2 and 80 grams of O2 per second, that should be doable even with solar cells. Assuming stoichiometric burn and 4400m/s exhaust speed (~450 second Isp) we get 396N thrust. Not much, but constant burn would consume 7.8 tons of propellant per day. Two week burn and whopping 109 tons are gone. Only moving part would be a little pump delivering 90cc of room temperature water to the electrolizer, at the pressure required for the rocket to work. Electrolizer would deliver high pressure gaseous H2 and O2 to the combustion chamber. It may be necessary to precool H2 using a heat exchanger aimed at cold outer space, so that it can used to cool the rocket engine. The big question is can such rocket engine be made that would withstand weeks of operation. I don't know but there are couple of points that at least make it easier. 1) It's only the injector/combustion chamber/nozzle that we are talking about, not the turbopump which almost certainly is the first thing to fail in normal rocket engine. 2) Because this engine would operate entirely in space, vacuum, t

tfrederick9 · Mar 25, 2005

Spacestar, not to get too hung up on the cyclers. However, I just want to make sure I understand what you are saying. You are proposing that the cycler drop you off in a high orbit while the cycler stays in orbit capture, and you get do you Mars entry on you own? I curious about instead of staying high in the gravity well, if you put the cycler in a high elipitical orbit and drop the Mars protion off for an aerobraking manouver. The cycler can then escape Mars orbit and contiune, or stay. I DO NOT know the DV numbers, and if this will gain you anything, I imagine the cyclers DV requirements would go up slightly and the insertion crafts numbers will go down. Its going to be very interesting to see the compromises we're going to see during this little endevour. The balance between reliablity, mass, cost, speed, fixablity, and complexity is going to be a difficult line to walk. I'm curious, should the systems be design with components that we know will fail and need replaced becuase of high wear, or take the approach and develop components that will survive the high wear, but have high cost and complexity.

spacester · Mar 25, 2005

"Hydrolizer Rocket" - an interesting curiousity, but not part of our Settlement plan. Very interesting though, great out of the box thinking. tfrederick, hmmm . . . I don't see the difference between your two descriptions . . . we seem to be describing the same thing. I'm not going to use the word cycler ever again

What I'm talking about is an Interplanetary Booster, a re-useable first stage of a true spaceship. Instead of a Boost from surface to space, it boosts you from Earth orbit to the rest of the solar system, then comes back for another mission. Our manned Mars Cruiser splits the dV mission into three stages. On getting to Mars, the craft targets the point where it falls into the gravity well to a specified minimmum altitude. You burn your engines as this happens, and the minimum altitude becomes the periapse of your HEMO. We burn just enough to achieve this orbit, that's as high in the gravity well as we can go without danger of not getting captured. This capture maneuver can be modified to include aerobraking if we so choose. Once capture is achieved, the second stage (for manned ships, the assembly of hab/truss/hub/truss/hab with canister) undocks and powers down to LMO. The hub would incorporate tanks and engines, I don't think I mentioned that before. The second stage has quite a bit of dV capability. The savings in my plan aren't from minimizing dV, but from splitting the dV up into managable chunks. Each stage has significant dV capability, but not so much that it's basically just a huge tank with other stuff attached. <div class="Discussion_UserSignature"> </div>

tfrederick9 · Mar 25, 2005

Spacestar, I had a feeling we where talking about the same thing. So we're banning "cycler" for good long while? <img src="/images/icons/wink.gif" /> Sounds good to me!

Let's Design a Settlement for Mars!

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