Using the ISS/Shuttle to go to both the Moon/Mars

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marcel_leonard

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I’ve been giving this quite a bit of thought and I’m of the opinion that we can go both to the Moon/Mars by using the combined resources of both the space shuttle, and the International Space Station. Instead of building a brand new vehicle to travel from the earth to the moon as was done on the late 1960s and early 1970s we could use the already existing shuttle to bus us to the ISS we could then build a lunar module at the space station designed to launch from the ISS platform and land successfully on the moons surface. As for a long term lunar base I propose we initially use the concept of a lunar mobile home. A self propelled vehicle that can double as a lunar rover and housing facility and laboratory.<br /><br />This will allow us the feasibility of a construction site trailer to later on design/build a more permanent underground lunar base. We can use this same approach to venture eventually to Mars were we could use this exact same off-world experience to build a long term Martian base of operation. It wouldn’t be a bad idea to resurrect the X-33/Venture Star program since the Aero-spike engines showed quite a bit of promise when they we at 75% design/build completion at their final testing at Huntsville AL. In an ideal world we would have already develop a low cost reusable launch vehicle (RLV) with the world community to make space delivery systems more cost effective not only of space exploration, but also for affordability of SatCom system design life cycles (SDLC). <br /> <div class="Discussion_UserSignature"> "A mind is a terrible thing to waste..." </div>
 
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john_powell

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I think this is a terrible idea. It would just slow things down and make it less safe. Consider that you would have to:<br /><br />1. Build the lunar lander on the ground. <br />2. Test it. <br />3. Disassemble it (carefully!) <br />4. Get it peicemeal to orbit.<br />5. Re-assemble it in zero-g (we're talking man-years of astronaut training here)<br />6. Fuel it in orbit (technological first?).<br />7. Test it again.<br />8. Launch to Moon.<br /><br />As opposed to:<br /><br />1. Build it.<br />2. Test it.<br />3. Launch to the moon.
 
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marcel_leonard

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Obviously you don't realize that in today's technology all spacecrafts are designed/built on the ground even the space station's is nothing more than modules built on the earth and joined in outer space in that case why should a lunar module be any different? <div class="Discussion_UserSignature"> "A mind is a terrible thing to waste..." </div>
 
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nibb31

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Obviously you don't realize a couple of things either:<br />1) The ISS is far from ready to become a space construction facilty. Reconversion would require a major redesign, the construction of new tools, new modules, and a way to get that stuff up.<br /><br />2) The shuttle is being retired and there is no means of transporting large elements such as construction material and large quantities of fuel to the ISS. So it's either many many launches or develop a heavy lift automated cargo vehicle. Both solutions would be costly.<br /><br />3) Above all, the ISS is in the wrong orbit to be of any use for serving as a base for deep space missions. Getting out of the ISS orbit and into lunar orbit would require as much propellant as getting there in the first place, negating the point of LEO assembly.<br /><br />Don't worry, you're not the first to come up with an idea that looks obvious but isn't at all practical. As often in space, it seems easy until you start doing the calculations.
 
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willpittenger

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If we reuse landers, we may have to refuel them. Might as well solve the problem. However, the other objects in this thread are good ones. <div class="Discussion_UserSignature"> <hr style="margin-top:0.5em;margin-bottom:0.5em" />Will Pittenger<hr style="margin-top:0.5em;margin-bottom:0.5em" />Add this user box to your Wikipedia User Page to show your support for the SDC forums: <div style="margin-left:1em">{{User:Will Pittenger/User Boxes/Space.com Account}}</div> </div>
 
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j05h

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>If we reuse landers, we may have to refuel them. Might as well solve the problem. However, the other objects in this thread are good ones.<br /><br />Yes, reusable landers are a great idea. No, docking them at ISS is not a good idea. Why double your fuel use like that? Why fly to and from one of the least efficient LEO inclinations? You would be better off building a polar-orbit station, at least you could get to the lunars poles easier. The Russians only use 51degrees because they are forced to between Baikonur and Plesetsk. ISS is in the wrong orbit for interplanetary servicing, you would know that if you spent any time on this site, or any other space forum: this subject comes up every 3 weeks, just like ISS-as-lunar-base or Shuttle-to-Moon. ISS as assembly base is a leftover from when the station was going to be dead-east of Cape Canaveral and KSC, pre-1993. <br /><br />I propose that this is all nonsense. Designate the 0-5degree inclinations as an industrial zone is a good idea. That is where lunar and martian missions should be assembled - on the equator serviced by SpaceX, SeaLaunch, Ariane, and Soyuz2 in the near future.<br /><br />Josh <br /> <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>
 
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scottb50

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If we re-use landers, we may have to refuel them. Might as well solve the problem. However, the other objects in this thread are good ones....<br /><br />I would hope you would re-use landers. The same lander could be used on the moon, Mars, a Comet or an asteroid, multiple times if needed. I see nowhere else we could go until we stop playing political games here on Earth. <br /><br /> <div class="Discussion_UserSignature"> </div>
 
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willpittenger

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I was thinking mainly of reusing landers on the same object. Reuse lunar landers on the Moon. Reuse Martian landers on Mars.<br /><br />I say that as the two will probably have different design requirements. If nothing else, the Martian version will need to hold more cargo and crew. (There might be separate crew and cargo landers. The crew version might allow some some cargo, but I suspect most of that would be spacesuits and similar equipment.) We will make fewer trips and can not readily ship fuel. While we can make fuel, it will almost certainly take time -- limiting the launch rate. With the Moon, we might still make fuel locally (which I like a lot), but it would not be as important (which I also like a lot).<br /><br />BTW: The ability to transfer fuel is VERY important if you make it on site.<br /><br />BTW 2: Some how the Russian Progress vehicles can transfer fuel NOW. I saw the details somewhere. Perhaps we should copy that and send them some royalty. <div class="Discussion_UserSignature"> <hr style="margin-top:0.5em;margin-bottom:0.5em" />Will Pittenger<hr style="margin-top:0.5em;margin-bottom:0.5em" />Add this user box to your Wikipedia User Page to show your support for the SDC forums: <div style="margin-left:1em">{{User:Will Pittenger/User Boxes/Space.com Account}}</div> </div>
 
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j05h

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Reusing landers and making in-situ propellant is absolutely critical to future exploration and development. That still doesn't change the fact that ISS is in completely the wrong orbit for servicing interplanetary craft. I'm trying to think of an example... umm, you don't try to cross the Pacific Ocean by starting in the Azore islands. Or, you don't try exploring a new river by first building a skyscraper. Anyway, in-situ resources and customized, reusable landers, are essential. <br /><br />Transferring fuel is an essential capability. I'm a big fan of the 'tank swap' instead of pumping fuel between tanks. Whatever works, though.<br /><br />Progress uses a funny technology called "pipes" and "valves" to transfer fuel and water. Also, Progress uses hypergolic fuel, so the actual hardware is going to be different than cryogenic or water transfer.<br /><br />Again, though, for all the ISS fans - why would you insist on doubling (at least) the fuel use and logistics of interplanetary missions? The station is not designed for servicing these missions, it is a research station not a maintenance depot.<br /><br />We need fuel/maintenance depots in intelligent inclinations, like equatorial LEO, not compromised orbits.<br /><br />Josh<br /> <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>
 
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marcel_leonard

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When I originally mentioned that I’ve given this subject some serious thought; I was doing more then just speculating on using the ISS as a mid-station to Mars/Moon missions, but actually doing some graduate level research for a paper that I am preparing on the future of SatCom space deliveries. There are three basic orbits that we currently use LEO, MEO, and of course GEO. With the right amount of propulsion which all satellites have in the event they should wish to alter their orbits in order to extend their SDLC (which for the average satellite is about 15 years plus, or minus). In all actually the ISS can be moved to a GEO polar orbit which would be more condusive to Lunar or Martian deliveries.<br /><br />The point being that you can't get around spending money if your are proponent of building a brand new Saturn-like heavy lift boosters to deliver some modern version of an Apollo mission capsule and lunar module. The “Nay-Sayers" always use the basic argument of the cost ineffectiveness of using our existing resources; case/point the shuttle and the space station:<br /><br /><i>“Obviously you don't realize a couple of things either: <br />1) The ISS is far from ready to become a space construction facilty. Reconversion would require a major redesign, the construction of new tools, new modules, and a way to get that stuff up. <br /><br />2) The shuttle is being retired and there is no means of transporting large elements such as construction material and large quantities of fuel to the ISS. So it's either many many launches or develop a heavy lift automated cargo vehicle. Both solutions would be costly. <br /><br />3) Above all, the ISS is in the wrong orbit to be of any use for serving as a base for deep space missions. Getting out of the ISS orbit and into lunar orbit would require as much propellant as getting there in the first place, negating the point of LEO assembly. <br /><br />Don't worry, you're not the first to come up with an idea that looks obvious but isn't</i> <div class="Discussion_UserSignature"> "A mind is a terrible thing to waste..." </div>
 
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tomnackid

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You realize of course that the energy required to get to the moon is the same wether you do it in two steps or one! If you dock with the space station before going to the moon you have to still bring all of the propellant you need with you--actually more since now you have docking and orbital maneuvering to account for. Plus more time on orbit means more consumables to bring along, more time for something to go wrong. And there is the whole less than desirable orbital inclanation issue. All in all using a space station as a "staging area" ends up making a mission cost a LOT more. The ONLY reason to do it is if you are limited to small launch vehicles as Von Braun assumed back in the 50s when he was designing his moon program. He was assuming low ISP engines powered by nitric acid and hydrozine. Back then he never could have imagined that he would get to play with anything like the massive rp1/lox F1 or the "holy grail" of rocketry--a lox/LH2 engine.<br /><br />If the space station were already full of fuel and supplies that DIDN'T have to be brought up from earth in the first place then the situation would be different. You can't cross a chasm by taking two small jumps!
 
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CalliArcale

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It's actually not a bad idea. The ISS is not ideal for this; a different orbit would be preferrable. However, it is better than nothing, and it's just about the only way we'd be able to reuse lunar landers.<br /><br />Well, there is one alternative. Place the lunar landers into an unoccupied parking orbit between missions. There isn't neccesarily any need to park them at the ISS, and the parking orbit could be more useful than the ISS's orbit. I don't forsee much major construction of these things in orbit, at least not in the near future; at most, I can see them being docked to some kind of booster rocket to propel them to the Moon. The value added from the ISS would be the ability to take a leisurely approach in getting them ready for the next mission (and perhaps even cleaning the things out before the new crew arrives to take it to the Moon again). I'm not sure that's worth the cost of having to stick these things into the ISS's orbit.<br /><br />If you simply leave the landers in a parking orbit between missions, the next mission would probably have to carry up additional fuel and such, as well as supplies for reprovisioning the craft. There would also have to be some procedure for removing and discarding trash so that it doesn't end up progressively more cluttered with each mission until the thing becomes unusable due to mess. <img src="/images/icons/wink.gif" /> But I suspect this would be more efficient than relying on the ISS crew to perform the processing functions.<br /><br />My big worry with this is whether the landers can be built sufficiently durable to be reused with only minimal servicing between missions. Their engines will have to be fired many times in a situation where the consequence of failure is the death of the entire crew. It might even be decided to go with solids, which could be more easily swapped in space, thereby avoiding the durability problem but introducing some entirely different problems. <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em>  -- The Tenth Doctor, "Blink"</font></p> </div>
 
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john_powell

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I don't think we should re-use landers as landers, I think we should re-use them as base materials.<br /><br />Something not brought up yet: <br /><br />I think we should only send <b>one-way</b> trips to the Moon and Mars. Pick folks whole want to make a career studying the place, and/or setting up colonies and raising families. I think we all agree the ultimate goal is colonization, so why not just start? It's certainly easier and more efficient to send folks one-way. I think Geoffery Landis did a back-of-the-envelope calculation and for the same mass budget a Mars mission could return astronauts to the Earth, OR send them with 40 years worth of food, air and water (with recycling of the air and water of course). Hmmm... 40 years of feet-on-the-ground-science per astronaut per launch or 6 months? For the Lunar mission, until colonies are self-sufficient, we can do one-way robotic and crewed re-supplies.<br /><br />I bet I know which option the Chinese are planning... And I'd hitch a ride with them if it were the only ticket available.
 
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marcel_leonard

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<i>"If the space station were already full of fuel and supplies that DIDN'T have to be brought up from earth in the first place then the situation would be different. You can't cross a chasm by taking two small jumps! "</i><br /><br />Who said the lunar module would have to be restocked by the space station? The lunar moduale could actually be delivered into lunar orbit automatically while the actual crew enjoys a visit aboard the ISS while they prepare their ISS to Moon transport for the mission. On return home their transport would dock again w/ the ISS in order to catch a ride home on the adjcently docked shuttle.<br /><br />The idea being we combine our existing budgets for the Shuttle, ISS, and Moon to reduce cost over runs created by NASA having three seperate operating cost... <div class="Discussion_UserSignature"> "A mind is a terrible thing to waste..." </div>
 
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nibb31

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Your proposal would be nice if propellant was free.<br /><br />Braking into LEO on the trip back to the moon requires as much propellant as it required to leave LEO in the 1st place. There's no free lunch. What goes up must go down and all that. <br /><br />The amount of energy required to slow down is the same amount as it was to accelerate. That doubles the mass of propellant required. With the difference that you actually need more propellant to accelerate because you have to the extra weight of the braking propellant, so your moon stack ends up weighing nearly 3 times what it did for a direct return with aerobraking as in Apollo or ESAS.<br /><br />So instead of having a CEV+SM+Lander+EDS leaving LEO, you have a Lander+EBS (Earth Braking Stage)+LDS (Lunar Departure Stage)+EDS, where your EBS is as big as the original EDS (or a Saturn IVB), the LDS is twice as big, and the EDS is twice as big as the EBS+LDS.<br /><br />We are talking something bigger than a Saturn V here, and assembled in zero G at the ISS. It would probably take years to assemble something that big. And of course, all of that mass will be disposable, just so that the Lander can be reused.<br /><br />And of course, there is the extra propellant that you would need for the inclination changes for getting in and out of the ISS orbit.<br /><br />Although you could reuse the lander in theory, it would be be much more wasteful.<br />
 
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krrr

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<font color="yellow">3) Above all, the ISS is in the wrong orbit to be of any use for serving as a base for deep space missions. Getting out of the ISS orbit and into lunar orbit would require as much propellant as getting there in the first place, negating the point of LEO assembly.</font><br /><br />The notion that the "ISS is in the wrong orbit" doesn't become truer by being repeated all the time. There's basically no penalty for going to the Moon from a high inclination earth orbit compared to a low inclination one. Similar for planetary trajectories.<br /><br />Of course, there's a penalty for payload from Earth surface to highly inclined LEOs. But that's just a few percent. <br />
 
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CalliArcale

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<blockquote><font class="small">In reply to:</font><hr /><p>I don't think we should re-use landers as landers, I think we should re-use them as base materials. <p><hr /></p></p></blockquote><br /><br />That's certainly more practical in the immediate future. In fact, NASA is planning with that in mind; they're designing the landers so that the abandoned descent stages can be of some use later on.<br /><br />One-way trips to the Moon or Mars may be a good idea someday, but technologically we just aren't ready for it. We would need some means of sustaining a crew for decades in a position where resupply just isn't practical. I don't think we've made enough advances to even reliably estimate how long it'll take to get the technology ready to support what amounts to a colony mission. <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em>  -- The Tenth Doctor, "Blink"</font></p> </div>
 
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specfiction

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Just to nail down a couple of things. Does anyone have a reference to a non-handwaving paper that lays out energy budget to the moon as a function of various Earth orbits, and those compared to Earth-to-orbit energy?<br /><br />Let's look at some actual numbers and/or calculations for standard masses of vehicles for some of these senarios.
 
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josh_simonson

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If one is going to re-use the lander, why bring it back to LEO? The optimal re-use system would send a normal sized EDS, CEV/SM, lander fuel and maybe some general purpose cargo pods to attach to the lander. Once mated with the lander in LLO or LL1/2 the fuel is transfered, equipment pods attached and crew transfered - then they descend. <br /><br />Rather than refurbish the landers at some LEO station, the landers should be refurbished at the moonbase while they're on the ground. That way the astronauts that work on the lander have other useful things they can work on in between landers. <br /><br /><br />Looking at the ESAS report, the fuel fraction needed to land is ~61% and the fuel fraction to ascend is ~45%. For a simple manned lander with no cargo and no lunar refueling this means the full lander will need a fuel fraction of 80%, or another 18.4T of fuel over the two stage lander with disposable descent stage (same problem with bloat SSTOs have). <br /><br />Now to send that 18.4T of fuel to the moon will require another 18 or so tons of EDS fuel, so your total mass to orbit goes UP by 36T for the re-useable system. The two stages of the lander cost a combined $640M, but making it re-useable requires 36 additional tons of fuel to LEO. If that fuel were launched on atlas IV, it would cost about $500M at today's prices, and the cost of improving the CaLV to 160T to maintain the 1.5 launch architecture is anyone's guess, and so is the additional cost of a fully re-useable lander. This shows that re-using the lander with fuel from earth is a dodgy proposition at best. Things look much better if the lander is re-fueled on the surface of the moon, but it will be some time before that is possible, and until then disposable landers will be the gameplan. <br /><br />Note that ESAS uses hydrogen for descent and methane for ascent, so my mass fractions are off by a bit compared to a combined descent ascent stage.<br /><br />Now if we only re-used the lunar ascent stage
 
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specfiction

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Okay, thanks for that reference. Assume what they say is true then we have that the delta-V ratio between LEO and LEO->L(ow)L(unar)O(rbit) is about 60%. <br /><br />Now the Energy required as function of delta-V is proportional to (delta-V)**2. So the ratio of energy reqired for LLO from LEO, assuming that the mass (of the craft) in LEO is 20% that on Earth (which is conservative) Then:<br /><br />Delta-KE(LEO-LLO) ~ 7.2%<br />---------------------------<br />Delta-KE(LEO)<br /><br />So aside from the boloney, about 8% of energy required to achieve LEO off surface of Earth is required to acheive Low Lunar Orbit from LEO. This is very doable in a variety of ways, many of which I consider much more attractive than the current NASA proposal, which I believe will fail because it's a(n) (expensive) dead end and produces no innovation.
 
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nibb31

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The mass of the craft does not change on the moon. Its weight does. The ISS is in microgravity, but its mass is still 200 tons. That mass comes into play when you want to move it.
 
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specfiction

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You misunderstand. I don't mean to imply mass changing in space or confusing mass with weight( = mg, where g is measured wherever you are in relation to massive bodies). <br /><br />I'm saying that between the surface of the Earth and LEO, a craft usually "sheds" 80=90% of its mass in fuel and stages--period. The Earth is a very deep Potential Energy well. At GSO, the gavitational potential energy is less than 20% what it is on the surface, at the moon it's < 2%. And furthermore, I'm not suggesting we take the ISS, there are many fun senarios that are much more interesting (in practical business-plan terms) to what NASA is proposing, which I believe is D(ead)O(n)A(rrival).
 
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specfiction

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You guys are rekindling my interest in all this. I'd given up on manned space as a lost cause a long time ago. My head hurt every time I heard Golden (who I liked very much, but who seemed like a man trying to swim with his hands tied) speak.<br /><br />If you don't mind my changing the subject a little, does anyone know exactly why the X-33 was cancelled?
 
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