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Working Hand In Glove Many of those enthusiastic about the president's new space policy want to redo Apollo. I pointed this out when it was first announced, but I didn't really describe all the implications of it. There are many, but I want to focus here on those aspects of it that affect our choice in launch systems to achieve the president's goals, whether existing, or new. There is an assumption that we cannot move humans beyond earth orbit without a heavy-lift vehicle, like the Saturn that first took men to the moon three and a half decades ago (and the fact that this July 20th will be the thirty-fifth anniversary of the first lunar landing makes me feel quite ancient). This assumption is based on the fact that it's how we did it the first time, and some have too little imagination to conceive that it could be done in any other way. But that was then, and this is now. What are the differences between then and now, in terms of our ability to fling humans beyond earth's orbit, and on to other worlds? First, of course, we know much more now than we did then, if for no other reason than we've done it. But more importantly, technology has advanced over the past third of a century since we first went to the moon, in a time period in which technology has been generally advancing at a dizzying pace, with a seeming continuous acceleration. Computers are much smaller and faster, materials are stronger with the ability to take higher temperatures, our ability to design is much greater, and our ability to get designs from a computer screen to functional hardware is phenomenal, compared to our capabilities in the 1960s. Consider also that our goal then was not to open up space in any sustainable way, but to simply beat the Russians to the moon. Under those conditions, our choice to launch a lunar mission on a single large rocket probably made sense. It wasn't cheap, but it was low risk, since we knew how to build big rockets (we only had to scale up what we already had), and we didn't know how to assemble things in space. But there seems to be an assumption on the part of many that large launch systems are an intrinsic requirement of manned space travel. Accordingly, they've skipped past the part of the trade studies that would determine whether or not this assumption is valid, and gone straight to debating the best way to get heavy lift. Of course, there's another motivation on the part of many engaged in such debates--a large launch system means a large development contract that provides continued employment for many who may fear losing their jobs when the space shuttle is phased out. There is a huge constituency for the Shuttle program--in Florida where they are processed and launched, in Utah where the Solid Rocket Boosters are manufactured, in Louisiana where the external tanks are built, and other places. The president's announcement that we will no longer fly the shuttle after the end of this decade had to have cast a pall over many people in those places, because even if the new initiative blossoms, there's no guarantee that it will benefit the communities that are currently supported by shuttle-based jobs. So it's not surprising that some are talking about building a new heavy-lift launch system that uses shuttle components. If they can't keep the orbiters, there are certainly many parts of NASA and its contractors that will work very hard to maintain the rest of the (costly) shuttle infrastructure. Concepts for shuttle-based launchers have been around as long as the shuttle itself, and many will claim that this is the fastest and cheapest route to the capability that they insist we need. But do we? Most people are unaware that other options were considered for Apollo, including earth orbit assembly, but as I wrote above, this mode was ultimately rejected as being too risky in terms of the primary goal--beating the Russians to the moon. But as the president said last month, this isn't a race--it's a journey, and we need to come up with modes of operation that recognize that, and make the journey an economically sustainable one. A heavy-lift vehicle, even a shuttle-derived one, will cost a lot to develop, and unless it flies enough, it will be difficult to amortize those development costs. Smaller vehicles, flown more often, will be more likely to reduce launch costs in the near term. The objection, of course, is that orbital assembly carries its own risks. What few realize is that this is because NASA hasn't really devoted the effort necessary to reducing them (particularly in developing space suits that don't tire out the astronauts). The current soft suit resists motion because bending a joint changes the volume of the air inside it, providing a force that wants to restore it to its original position. Think of a rubber glove, limp until inflated, but difficult to bend the fingers once under pressure. In fact, the glove is the biggest problem in designing the high-pressure space suits necessary to avoid the bends (the same problem a diver has when she surfaces too quickly) when an astronaut goes out into the vacuum of space. Larger joints like shoulders and knees have special designs that are zero-volume change, but no one has yet miniaturized such a design to finger joints. Because this is a critical technology, and one that has great leverage in influencing launch system trades, I would propose the following: Build a vacuum glove box with a task box inside (perhaps an automobile engine that has to be dissassembled and reassembled). Put up a purse of a million dollars to the first person who can achieve the task working through gloves under a pressure differential of half an atmosphere, without a break. Unlike many space activities, it's a project that can be literally done in someone's garage, and it may spur a great amount of innovation for very low cost. Accordingly, it would make an excellent candidate for the Office of Exploration's new prize fund, and I hope they'll strongly consider it. At very low cost to the taxpayers, one or more successful concepts could lay to rest myths about the intrinsic difficulty of working in space, opening up the options for how we will get to the planets beyond redoing Apollo, perhaps saving billions in dollars, and constituting a major step toward becoming a truly spacefaring nation. Posted by Rand Simberg at February 18, 2004 07:31 AMTrackBack URL for this entry:
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Great idea! I'd go a bit farther, and make it two tiered (1/2 and 0 atm) and a second prize for both levels so as to encourage people to not give up on projects 90% complete when someone wins the initial prize. This is a good idea. But by selecting a pressure difference of 0.5 atmospheres you have excluded skinsuits. Prices should *never* make any assumptions about how the problem is to be solved. They should just state the problem and reward any practical solution. I think skinsuits with low pressure pure oxygen are much better than hard suits with high pressure. A hard suit with tens of very delicate mechanical joints is an expensive high tech device. A skinsuit for low pressure oxygen might be as cheap and simple as a normal diving suit. And a skinsuit is much more robust than a hard suit: a small hole in a skinsuit just produces a very nasty bruise, You could repair it like a bicycle tire. The fire risk of a low pressure pure oxygen atmosphere is highly overrated. And if you have simple and easy-to-use skinsuits there is a very simple way to stop a fire: just don your suit and purge the atmosphere. Posted by Rüdiger Klaehn at February 18, 2004 09:42 AMI'm not excluding skinsuits, Rüdiger, but a low-pressure suit won't eliminate bends, even with pure O2--you'll still have to pre-breathe for several hours prior to egress, which is one of the problems with current orbital assembly. We really need high-pressure suits, whether conventional soft or hard suits, or skin suits. Posted by Rand Simberg at February 18, 2004 09:52 AMAnother problem that has plagued current space gloves is the fact that a large number of coolant/heater lines have to run up and down each finger. These lines and there fastening points along the glove tangle, poke, pinch, and crimp against the astronauts fingers and have been described as painful by some. NASA's answer to the pressure problem has been to operate the suits at a lower pressure compared, to say the Russian suits. The suits that NASA uses operate at about the same PSI as a fully inflated football (american) and therefore the astronauts have to spend about an hour in the airlock prebreathing pure oxygen to avoid the bends. The lower pressure produces less resistance to joint movement. While the russians who have been more involved with space station construction/maintenance, know that you can never get anything done on a timely basis if your cosmonauts are sitting around pre-breathing pure oxygen everytime they need to go outside the station. Posted by hefty at February 18, 2004 09:57 AMWhat every happened to the accordian joints favored by Arthur C. Clarke (and shown in 2001). The amount of pressure in the joint would stay the same, just move around a bit. Posted by ruprecht at February 18, 2004 09:59 AMAnother question. I can see why NASA doesn't want to use pure oxygen at Sea Level (Apollo 1 and all) but why not shift the orbiter over during flight. Everyone can breath 1/3 pressure so those going outside aren't treated any differently. Posted by ruprecht at February 18, 2004 10:03 AMYour assumptions about prebreathing presuppose that the atmosphere of all space habitats must and forever shall be 14.7 psi. This is an assumption that needs to be questioned. One wants a tissue pressure ratio (partial pressure of nitrogen in the cabin/pressure of all gases in the suit) of 1.4 for honest instant-out capability. This is in fact lower than the current shuttle protocol, by the way. Prebreathing pure O2 is a way of taking advantage of the physiological fact that the half life of nitrogen in the blood is about two hours. Further, cabin air should not be more than 30% oxygen as a matter of fire safety. Fire risk depends on both the partial pressure of oxygen AND the concentration of oxygen, because of the cooling effect of the nitrogen in the cabin mixture. Consequently, a cabin atmosphere of 70%N2/30%O2 at 8 psi permits a skinsuit on 100% oxygen to operate at 4 psi. As long as there's a no-EVA the first day rule, I think this gas mixture should be preferred. I should mention that I wrote a thesis on this stuff back in 1984 and have built hybrid skinsuit/Apollo-era suit gloves, and tested them in a vacuum glove box. Posted by Mitchell Burnside Clapp at February 18, 2004 10:48 AMI'm perfectly happy to question the assumption, Mitch, but there are certainly a lot of advantages to a standard atmosphere (e.g., for science, it allows one to do controlled experiments on the ground, keeping equipment cool is much easier, etc.). If someone wins the prize, it makes it much more attractive to use a full atmosphere in orbital (and lunar) facilities. It would be nice to have the option, even if not all facilities are at 14.7. We have to do an overall systems trade, but it would be a nice technology to have in the mix, if it's doable. A prize would determine whether or not it is, with no cost to the taxpayer until success. Besides, it sounds as though if we set the bar as low as you propose, you've already won. That couldn't be what you had in mind, could it? ;-) Posted by Rand Simberg at February 18, 2004 10:58 AMI think you've managed to skip over some of the other issues involved in the selection of a launch vehicle for lunar missions. It is not simply the difficulty of construction in zero-g/zero-atmosphere, it is also the issue of interfaces. The Stafford Synthesis Group back in 1991 selected a heavy launch vehicle for both of these reasons. They thought that something equivalent to about 1.5 Saturn V's was needed. However, it is worth noting that NASA now has considerably more EVA experience than it did at that time. (Somebody should be able to look up the cumulative EVA totals for summer 1991 and today.) That might affect the discussion. The issue of interfaces remains, however. Stafford's group concluded that these added complexity and increased the possibility of failure. Generally, from what I've seen of past studies, it seems that in order to do meaningful work on the lunar surface you have to get at the very least about 100-120K pounds into LEO. The problem has been that if you split this into dual launches, you can barely fit it on shuttles and Titan IVs (the previous benchmark). Proposals to do this always pushed the limits. For instance, the shuttle would have to exceed its safe abort weight. And this only got you a piloted landing vehicle--if you wanted a habitat on the surface, you needed another dual launch. So that's four launches to do an extended stay lunar mission. However, if you had an ELV with at least 70K pound LEO capability, dual launches become more feasible ways to achieve these goals using the Earth Orbit Rendezvous approach. And bigger is even better. You still have to do multiple launches, however. It is worth noting that the Delta IV (and maybe the Atlas 5) have tried to minimize ground processing time. This has been one obstacle to dual launch lunar missions using Earth Orbit Rendezvous. So that is one thing that has improved since the early 1990s, when NASA last revisited this subject. In addition, Delta IV may be upgradable to 100K pounds to LEO or more. I'd have to check the numbers on that. Posted by Dwayne A. Day at February 18, 2004 12:21 PMI've no doubt skipped many issues (but I'll address them in future pieces). The dirty little secret is that this is this week's Fox News column, and I have a word limit, and no time to do a shorter version. But to me, it gets back to what being a spacefaring nation means, and if we're serious about becoming one. One of the features of one is that orbital operations, including assembly, mating (and getting the interface issues resolved) are routine. I'd rather develop that basic infrastructure and capability than rush back to the moon a la Apollo, because it will give us a much firmer base on which to operate sustainably. Posted by Rand Simberg at February 18, 2004 12:33 PMWell, if that is all that you're interested in, why not cancel everything and just sit on the ground until somebody comes up with the perfect glove? Then we can wait for the CATS windfall that we have been told is just around the corner for about a decade now. Yeah, yeah, rhetorical cheap shot. However, I think that in your column you committed one of the same sins that you accuse NASA of doing, which is handwaiving. You claim that they assume a Saturn V is needed because A) that's the way we did it with Apollo, and B) they are wedded to big infrastructure projects. Both of those may be true, but then you skip over the technical issues yourself--the big issue that there is apparently a practical limit to how small we can make the components of a lunar return mission. That practical limit appears to be around 50-60K pounds. But it is also true from looking at past proposals that bigger is still better, for indeterminate values of "big." I agree that a super heavy booster may not be needed (but man, it would be cool, wouldn't it?), and I also agree with a previous claim that you or somebody else made that once NASA starts shutting down shuttle infrastructure, Shuttle-C may not be a sustainable option, especially if the agency is going to use the money to fund CEV. But that doesn't mean that some kind of booster upgrade will not be needed. Fortunately, there appear to be some useful options. Posted by Dwayne A. Day at February 18, 2004 01:38 PM[Rhetorical cheap shot appropriately ignored] ...there is apparently a practical limit to how small we can make the components of a lunar return mission. That practical limit appears to be around 50-60K pounds. That is more apparent to some than others. It's not at all so to me. There is a practical limit, but I think that it's closer to ten thousand than sixty thousand pounds. As I said, it all depends on your assumption set. I hope that we can take a clean-sheet approach to these trade analyses, because I do believe that while it wasn't quite as fundamental as September 11, January 14, 2004 should mark a watershed in our thinking about space. The fact that we aren't in a rush to get to the moon should cause us to rethink a lot of past assumptions and paradigms. Of course, I was challenging those even on January 13th (and in 1989)... Posted by Rand Simberg at February 18, 2004 01:52 PMDwayne, Both of those may be true, but then you skip over the technical issues yourself--the big issue that there is apparently a practical limit to how small we can make the components of a lunar return mission. That practical limit appears to be around 50-60K pounds. But it is also true from looking at past proposals that bigger is still better, for indeterminate values of "big." I have to disagree with you on this and agree more with Rand. I think one of the key questions that hasn't really been looked into well is "how small of a chunk can you break things up into and still get something useful at the other end"? For instance, how many people do you really need to send on a single earth-to-luna flight? Does it really have to be three, or can it be two, or can it be one? What is the smallest size you can break the cargo up into--ie do you have something that has to be shipped in one piece that is bigger than 1000lbs? 2000lbs? Can you preland enough cargo ahead of the manned vehicle to allow you to do real things without needing a big launch vehicle? I'll let you answer those on your own, but from past work that George Herbert has done, and work that I have done, I think the answer is a whole lot smaller than most people think. Rand thinks 10,000lbs is about the lower limit, but I'll be heretical enough to say the bottom limit appears to be about 3000-3400lbs on the lunar surface. That's enough for a rover or a SpaceHab module, or a crew return vehicle that can send one person all the way back to earth. It is enough to fit a small nuclear reactor (like the russian TOPAZ), or radiators, or solar cells, or a small ISRU test facility. Anyhow, if you limit yourself to chunks in that ballpark range, you can launch them on a single Atlas V 401, on a Delta IV (maybe not even a Delta-IVH), an Ariane V, a Proton, a Zenit, or on 4 Falcon V launches........ Anyhow, I have to agree very strongly with Rand. From all the analyses I've seen and done, you don't need a heavy lift vehicle, and in fact may not even need a huge amount of on-orbit assembly to return to the moon. I have some more thoughts, but that's all for now. ~Jon PS I liked the glove box prize idea. It might be doable independently of NASA, even if they don't want to tackle the problem. Posted by at February 18, 2004 02:37 PMBy ?skinsuit? I assume you mean a suit that is porous, but provides tension to prevent bloating and other nastyness. That?s a pretty common concept in science fiction (although there is another type of ?skinsuit? in SF that is nanotech based) but how much real research has been done on it? I haven't seen many references. I did find an internet reference on skinsuit gloves, specifically talking about a hybrid system (see www.ssoar.org/outreach/undergraduate/ projects/project3/gloves.PPT). Also, current suit schemes are largely passive (skin or otherwise). Active and semi-active systems should be researched - sensors and arrays of pneumatic bladders could dynamically correct small gaps in a skinsuit. Active assists for the joints, at least for the hand, could help with bending issues. There?s a lot of possible tricks to keep the bulk and mass down. On big launchers ? IF you are talking about a NEW REUSABLE design, there is one major advantage to a big lifter: You can get a useful payload for a SSTO even if fuel and structure account for a very high percentage of the launch weight. If it is a reliable fail-safe design, that could be far cheaper to run, even if it isn?t technically very efficient. Posted by VR at February 18, 2004 03:28 PMThe reference that VR posted above does a reasonable job of recapping my research and results at a top level. I'm embarassed to realize that it was 20 years ago this month that I was typing most of that stuff up. I wouldn't do a hybrid suit precisely the same way nowadays, but I think the fundamental approach is sound. Posted by Mitchell Burnside Clapp at February 18, 2004 03:57 PMThe Artemis Projects' reference mission had some interesting ideas (open cockpit lander, etc) and was speced out to be done with existing launch system (no heavy lift).http://www.asi.org/adb/04/02/spacecraft-info.html Posted by Michael Mealling at February 18, 2004 04:09 PMMichael, I think it may be possible to split the Artemis Reference Mission up over more smaller launches. While there are some drawbacks to this approach, I think there are some benefits too. I'm trying to put together a tentative presentation for the Space Access '04 conference about some ideas for a fully commercial lunar project with "islands of profitability" between here and there......come to think of it, would you like to collaborate with me on that? ~Jon HLLV versus lots and lots of little boosters would seem to be a "bean counter" question. What is the cheapest pound to LEO option? Why can't shuttle C development be funded with the STS money already earmarked to finish ISS? One shuttle C launch plus one nearly simultaneous orbiter launch can lift 4 ISS component payloads. 6 orbiter mission with 6 simultaneous shuttle C equals 24 orbiter missions. If we cannot get that to cost less than the STS budget between now and 2010, America ain't going to settle space any time soon. Call it a test of Sean O'Keefe's management skills. Design and deploy shuttle C within the current STS budget already earmarked to finish ISS. Posted by Bill White at February 18, 2004 05:24 PMWould we even consider small LV's if we had Saturn V's or Shuttle C's available to us today? I'm sure the Russians would be happy to sell us capability in that range long before we ever need it. Put out a request for bid for a dozen big dumb boosters on a ten year contract and get on with the rest of the planning. Why is nitrogen the filler gas of choice? Do we need space suits at all for EVA? Why not a one man pod with robotic arms? A shirt sleeve, recumbent working environment would allow for a long working day. Put a heat shield and parachute on the deluxe model and you've got a life boat. Further thoughts about HLLV via space radiation dangers. This link is being broadcast by NASA to its e-mail subscribers: http://science.nasa.gov/headlines/y2004/17feb_radiation.htm There is a very good chance that plastic spacecraft will become necessary because of the danger of daughter radiation arising from cosmic rays striking metal nucleii in the spacecraft hull. It also may prove true that thick layers of boron doped polyethylene may be necessary to shield astronauts or else we made need to use vast quantities of water in deep space or on the moon. Liquid hydrogen has its advantages except that its cryogenic. Plain old water has advantages for ease of handling and its ability to act as a heat sink for heating and cooling the habitat. ISS is cold because of its aluminium construction. Anyway, this stuff is heavy. Adding a couple of feet of water balloon between the crew and outer space will need plenty of heavy lift capability. It would be a shame to chainsaw the shuttle infrastructure, let Pad 39 rust like that Apollo pad, tear down the VAB, and cut up the crawler for scrap only to discover in 2018 that we really need a new HLLV. Especially since I believe shuttle C deployment can be funded within the current STS budget for ISS completion. In addition, one shuttle C launch could be sold to Space Adventures for a mini-Mir space hotel. One idea - - they buy Russia's spare Zarya module (they made 2 for ISS) and they buy a TransHab module from SpaceHab and they design and buy a docking port allowing access for multiple Soyuz / Progress. Lift to space on shuttle C and have room for 4 or 6 space tourists all at one time. Can you visualize the ultimate chic honeymoon for the rich and famous? Delta IV & Atlas V just can't do that. Adding a couple of feet of water balloon between the crew and outer space will need plenty of heavy lift capability. No, it requires cheap lift capability, not heavy lift capability. ...one shuttle C launch could be sold to Space Adventures for a mini-Mir space hotel. Not at any price that they'll be either willing, or able to afford. Instead of drooling over expensive heavy-lift vehicles, people need to get a little more imaginative. Posted by Rand Simberg at February 18, 2004 06:44 PMSpace hotels are a tangent. The key question is whether the launch services needed for ISS completion can be provided with less expense via shuttle C plus orbiter or via orbiter alone. This is a "bean counting" question and the taxpayers deserve an answer, IMHO. It appears ISS components can fit inside a Delta IV dual manifest payload fairing (slightly modified) yet it is unclear whether Delta IV has the oomph needed to get ISS components all the way to 51 degrees inclination along with a payload delivery module. Probably not, but that is worth looking into as well. What costs less? That is the key question and I submit we just do not know yet whether EELV or HLLV will prove cheaper in the long run. Therefore, to chainsaw a potential shuttle derived capability before that question is answered just seems foolish. Next, one way to lower costs is to increase demand. A genuine space hotel will stimulate great demand for carrying tourists, food, water and clean sheets. If NASA lifted a small hotel (Zarya + TransHab + docking module) in the immediate future Soyuz/Progress would be the only option for travel and re-supply. However the ESA and Japanese transfer vessels are nearly on-line and Elon Musk would have a potential paying customer both for re-supply and tourists if he goes forward with a larger man-rated Falcon. Burt Rutan and Kistler could also compete for Earth to space hotel contracts. NASA puts the thing up and then leaves ALL support missions to the private sector. Finally, paying for a space hotel. A US administration sympathetic to commercial space would be a great start. What about name rights? http://www.bizstrat.com/fa0503.html http://www.bizjournals.com/philadelphia/stories/2003/09/15/focus3.html?t=printable How much might Hilton, Marriott, Hyatt for example pay for the name and logo of the first commercial space hotel? The docking module name rights could be sold as a stand alone deal to a major airline and these airlines could "business partner" with the various launch services. FedEx sponsors Elon Musk, JAL sponsors the Japanese cargo transfer craft, etc. . . Raise $50 or $100 million for a multi-year deal to film McDonalds ads in the hotel. Guests must eat (or pretend to eat) microwave heated fast food for the cameras. Maybe it would work and maybe not, but without HLLV operational today it won't happen for another 20 years. Rand, I thought this was the kind of stuff you favored? I am enthusiastic about the President's new space policy, but I definitely do not want to redo Apollo. "Spirit" and "Opportunity" are (okay, at least were when people were still paying attention) household names, but I wonder how many taxpaying Americans can name the launch vehicles used in those missions? Is access to space via an airplane ferry (think SpaceShipOne via White Knight) a viable option, perhaps as a way to increase safety for launching the crew vehicle? Or is this design inherently limited to suborbital missions? Isn't the math a little off in this link from Bill White... Can People go to Mars? They add 20% to 19% and call it 39%... Should it not be 20% + (19% of 80%) or about 36%. Otherwise you would have a situation where you get 100% chance of getting cancer from a radiation dosage that's more likely to just kill you (giving zero percent chance of dying of cancer, right?) Not to mention that these numbers appear ridiculously high. Posted by ken anthony at February 18, 2004 10:36 PMHow do you control an EVA Pods hands... Perhaps one day? Posted by ken anthony at February 18, 2004 10:51 PMI tend to agree with Dwayne here, I'm not convinced that some of these assembly and mating operations will ever be easy or routine in the environment. At least without developing some isoteric technology to deal with the practicalities of the environment. Jon is right about what you can do with a single Proton-class launch - I think it would be enough to land an inflatable habitat, or supply a manned outpost, but I don't think it allows you to do much more, even with multiple launches. Plus we're hardly talking then about real space development. We could have a reasonable cost moonbase using EOR assembly of a couple of TLI stages, a return module and lander - or put the lander in Lunar Orbit with a similar system. And prior to that land a habitat, rover and supplies. I can't see the cost on that even with today's launch vehicles being huge - I suspect you could subcontract it as a project to the Russians for a pretty reasonable sum. Regarding the whole Many vs. Few Pieces debate, there was a pair of articles in the (IIRC)Nov/Dec issue of JBIS that attempted to examine exactly this issue. A 'many pieces' view *that bootstraps from Space Station* must account for not only the parasitic weight of the interfaces between modules, but also all the other costs associated with ensuring that the interfaces work properly. I seem to recall that the thrust of the articles was that, in the realm of shuttle vs. shuttle C for space station, it would've been better to spend the extra $$ to implement shuttle C. For lunar missions, we're ~20 years farther down the road, so the trade may very well be different. The key point is that this is a system trade that needs to be made, the sooner the better, and it should be influenced by the desire to establish a more lasting paradigm. For instance, I don't think anyone has done a cost trade to compare implementation costs of an HLLV vs. spending that on a nice simple 'universal' module interfacing scheme. IMHO, it would be well worth a billion or two if we could couple s/c modules like we currently couple railroad cars. (Then we can simply buy launches on whoever has the current best deal at the desired payload...) - Eric. Posted by Eric at February 19, 2004 06:39 AMFrom what I understand Solid Rockets give more bang for the buck but they are dangerous because you can't turn the rocket off once it starts (unless you use some new hybrid). Knowing that, why can't we strap a few solid rocket boosters (and enough of a liquid system to get the thing into a stable orbit) and fire a bulk payload of H2O into orbit? I imagine a lot of equations change if you could refuel in orbit. Where am I going wrong? Posted by ruprecht at February 19, 2004 06:52 AMI like Eric's rail car analogy. So why can't we build really big ships with modular shuttle C payloads? And what is the parasitic weight of using the orbiter to deliver inert metal trusses or modular nodes one by one to ISS rather than in bundles of three via shuttle C? For cargo, large packaging would seem cheaper (per pound)than small packaging but until Project Constellation produces a proposed EELV system we simply cannot do the cost trade analysis Eric proposes. Also, as ruprecht said, if water becomes the radiation shield of choice, the ability to lift a 75,000 kg water tank to LEO in a single throw will surely be cheaper than using dozens of Delta IV flights. Since we cannot do Eric's cost trade analysis until Project Constellation chooses a system I suggest that to chainsaw shuttle derived capability now just seems foolish. Remember, Shuttle C need not ever become man-rated. That decision can be postponed. Yet Shuttle C plus Project Constellation allows cargo to travel on solid rockets and crew to travel on Delta IV or Atlas V or whatever. What should be done NOW is a cost trade analysis on using a blend of orbiter and Shuttle C to complete ISS. The orbiter won't fly until 2005 anyway and since every one Shuttle C flight eliminates the need for three orbiter flights there is a very real chance that shuttle C deployment can be funded entirely from the money already earmarked by President Bush for STS operations. IIRC Shuttle C was cancelled in 1992 because it would have undermined the orbiter program and the orbiter was needed to do other things (like Hubble). Since we now know the orbiter will do nothing except finish ISS perhaps we should re-visit that 1992 decision. Bill, The parasitic weight on Space Station are called Nodes 1, 2, and 3 (plus the docking adapter hardware on all the modules that attach to the nodes). As for the cost trade, there should be no need to wait, since Constellation (allegedly) isn't going to be producing a new booster. And besides, you don't necessarily need a new booster to send up the moon ship in pieces. Those attempting such a trade would just include Atlas V, Delta IV, Ariane 5 and Proton as alternatives. I think that, as neat as Aldrin's Shuttle-derived launcher is (and I'd *LOVE* to be at a launch of one), unless there's truly going to be a volume of large launches (i.e., SBL gets approved someday or something), you'll be better off improving the economics of the existing boosters. Also, something in the 50Klb payload range just might be in striking range of some of the alt.space boosters in the next ten years. And I have the feeling that when that happens, you'll have your 250Klb booster if you want it, and at much lower cost. - Eric. Posted by Eric at February 19, 2004 05:29 PMThe beauty of the invisible hand (if you'll pardon the pun) of free markets is that all things are tried. In fact, this is the argument which most moves me against the majority of government programs: there can be only one way. If space were a market-driven activity, all kinds of combinations of hard, soft and hybrid suits would be tried, including the Alvin-alikes (pods with manipulators). Some designs would work, and would be improved upon. Others would fail and be discarded. As long as it's the government or nothing, there's only one way, and it's completely irrelevant what it is, because you and I will never get the chance to do it ourselves. VR Posted: "Skinsuit" won't get you many results, but "Mechanical Counter-Pressure Space Suit" will :o) That's the 'technical' name, and not only was some good work done on the basic concept during the 50s-60s, but there is still work going on. Some of the links I've found: The 'orginal' work was done under the title: It has some good links to the original documents. As for Glove work: Randy Posted by Randy Campbell at February 27, 2004 10:16 AMI think maybe they could come up with a robotic type hands/left and right with arms that the spaceman could use while wearing his suite or in a machine that has that single person would run all done by press button or by thoughts of the on running the machine.It could pocket the items it is picking up sorting them out so items would not get mixed up.It could have a small digger on it like a tractor only in a small toy type version for taking soil samples.A robbot suite fit for most people.this way it can bend and move pick up float to places without going up into the atmosphere.It can send pictures back to the others on the mision have a light source and it would carry plenty of oxegen for the user of the mission.In most cases it is better with to if something would happen or he/she would need help.Acually one in the regular suite the other in the specialized suite.the hands would be just like real hands...so a new glove would not have worked up.Something like they use for people who where hurt in accidents ect.... prosthesis/hospital proffessionals could develop something special and low cost but specifically of saftey minded for the astronauts and that would resist space atmophere. Posted by Diane Luchterhand at May 10, 2004 09:33 AMI back going to the moon and going to mars also.The moon is a great place to start and learn about the possibilities of going to mars.They are different but have their own challenges.Here they can get a great start and get good knowledge before taking on the bigger challenge of going to mars and they would be closer to earth where they could have help if needed.That still is a while away...Live and prosper! Quote: {We will explore the heavens and be welcomed among the stars and the planets.} Posted by Diane Luchterhand at May 10, 2004 09:55 AMIs this glove contest for real? I mean if it's so, I made a design that could work even at a 1 bar or higher difference of pressure. Is there an official site for this contest? Posted by Crisan Cristian at September 7, 2004 04:26 PMFor a small lunar base, one would need a habitat, life support and power. For a base to grow, one would also need atleast limited manufacturing capabilities and preferably a greenhouse. If I'm not completely off target, a small but sustainable base should be possible with only 4 Ariane 5 launches. A basic habitat/life-support/command module, The empty stage would acompany the pieces down to the surface to become another part of the base. But basicly, A crew of 3 chould start construction with only 4-5 launches. and we allready have the technology for this. Someone only need to take the initiative.
Note however that this sollution does not include a laboratory or scientific equipment. And there is a simple reason. First build the base, then use it. Posted by Thaniel at October 10, 2004 07:06 PMI am not a scientist or anything like that. It seems to me there are two ways to get to sapce, the brute force way and the slow and steady way. Shuttle, boosters... have huge WOW factor. but they are the brute force way. We are expending thousand of KG of fule to lift Fule and the ship into space. Two things come to mind as slow and easy, 1 a space teather that alows you to inch your way up to space, carbon nanotubes seem like the material for it, but as i under stand it pure carbon "rusts" in space from free ratical Oxegyon. the other is things like the solar powered plane, if this could be expanded to allow you to carry a craft to the edge of space on solar power, then who cares if it takes 3 weeks to get there and then light the booster for the last push. a 1000 kg of water doesn't mind waiting 3 weeks get to space. and save the brute force for lifting the human crew that do mind waiting. my 2 cp. Maybe i am iss understanding the problem with the gloves, but a couple of ideas come to mind, a cylinder inside the suit that has a vacume in one side, and a servo plunger on the other. as the compute detects the gloves flexing it componsates by moving the plunger to keep the airpressure constant while the volume of the suit changes. and why not a hybrid approch. a skinn tight glove that provides 0.5 of the space suits pressure evenly across the hands, and a gasget at the wrist, then lower the pressure in the gloves by 0.5 of the suit pressure. the hands would still have the same pressure on them but there is a much lower presure in the gloves to work against? thanks for reading my ramblings.
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