ISS Debate

spacester · Oct 30, 2005

Hey orrery21, do you want to have a debate on the merits of ISS? You see, I know you've been around here a long time, and I've never thought of you as a troll. And I still don't. It's just that if some of us are going to try to do something about the trolls around here, your unpopular opinions might get you swept up in the dragnet. That would be an injustice IMO. I think you are capable of showing how a poster can have strong unpopular opinions and still not be a troll. I wouldn't normally think of challenging someone to a debate, and if I did, I would do a lot of research first. But I'm making an exception here - I don't actually know a lot about ISS. So it may be that the "pro-ISS" position will be better represented by others here and maybe I'll fade out. At any rate, are you game? We can show folks how things were around here in the old days (at least some of the time). My position: ISS must be finished by STS if at all possible. So please state your position in simple terms like that, and then you have the floor. (Others can respond of course, in whatever fashion they deem appropriate.) <img src="/images/icons/laugh.gif" /> <div class="Discussion_UserSignature"> </div>

mattblack · Oct 30, 2005

(Sharp intake of breath) Ooohh, spacester; are you sure this is a good idea? What am I saying? It's not my forum to censor... Go for it!!! <div class="Discussion_UserSignature"> One Percent of Federal Funding For Space: America CAN Afford it!! LEO is a Prison -- It's time for a JAILBREAK!! </div>

JonClarke · Oct 30, 2005

Let's dispose of one myth straight off - the "No science is done on the ISS" myth. Searching using a standard search engine on scientific publications shows that there have been already a similar number (more than 2000) of papers generated as during the Apollo program, twice as many as by Mir, and about half as many as the entire 20 years or so period of shuttle operations What has been learned from the ISS program to date? The US in particular as gained a huge about of experience it would not otherwise have had with regard to long duration space flight, continuous space operations, and orbital assembly. It has also tapped the vast Russian experience in these areas. The for Russians the benefit has been funding for the construction for the Zvzeda module, exposure to western approaches to management. As yet the Japanese, Europeans and Brazialians have seen little hard results, which is white it is essential for the US to fulfill its obligations in launching the ESA and JAXA modules ASAP. Without experience of long duration missions and orbital assembly in LEO there will be no missions beyond the moon. The ISS is the only available platform to do this, and should be developed and used to its maximum potential. 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>

dobbins · Oct 30, 2005

The problem with the ISS isn't that no science is being done, it's that the WRONG science is being done. We knew that prolonged exposure to a micro-gravity environment was unhealthy before the first module was designed, left alone launched. We need to be working on artificial gravity. We need a station that can be used as an operational base in addition to a research base, and the high inclination orbit precludes that. It's the wrong station in the wrong orbit. That does NOT mean I think we should dump it, shoot it down, or not complete it. The research still has some value, and we have a made a commitment to our partners that we should honor.

j05h · Oct 30, 2005

i'm not saying this is my opinion, but I just thought of a no-Shuttle alternative. Why not pull the experiment racks from Kibo and Columbus, and install them in ATV or HTV transports? Just launch on Ariane, dock to CBMs on the Node and call it good. I support finishing ISS, preferably without Shuttle, but not at the expense of developing a sustainable interplanetary transport system. Josh <div class="Discussion_UserSignature"> <div align="center">We need a first generation of pioneers. </div> </div>

shoogerbrugge · Oct 30, 2005

You also need donwload capability, that is the real advantage of the STS, it can take payload down to earth...

JonClarke · Oct 30, 2005

regardless of whether or not spin gravity is required, many of the basic operational issues managing long duration spaceflight and orbital assembly are the same. The ISS is the only platform for it at present. As for spin gravity, while good in theory, when you look at it it detail there are a huge range of issues. It is expensive in terms of mass, and imposes quite a bit of complexity, however it is done. The phsyological effects of long term exposure are lot understood at all, whereas the effects of microgravity are - and some reasonably effective countermeasures. There are some very innovative and promising technologies that are in their infancy that need to be researched. But spin gravity need more work definitely. That is why I will be seriously disapointed if the centrifuge module does not fly, as this was one of the most important payloads i have seen proposed. 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>

erioladastra · Oct 30, 2005

HTV cannot dock to the node (it could berth but the radio prox link, control system etc is all in the JEM). But also, the ISS is full, you would have to pull other racks out to make room for those - which is only a few since most right now are system racks, required storage etc. Plus you need a way to get the stuff back down. Finally, HTV and ATV do not have the upmass of Shuttle so it would take many more.

erioladastra · Oct 30, 2005

"We need to be working on artificial gravity. " Actually I don't think so. Everything I have heard is that micro-g is not a serious or unsurmountable issue for a Mars mission. However, radiation shielding, regenerative life support, maintenence and repairs in long duration, logisitics etc are all the big hurdles.

dobbins · Oct 30, 2005

I disagree about it being a problem for a Mars mission. At the very least the crew will be in a weakened condition after a prolonged exposure to microgravity on the way to Mars and that will affect their ability to perform once they arrive. We don't have any data on a prolonged exposure to reduced gravity, if it will solve some or all of the problems of microgravity. That is data that is needed for planning a Moon base or a Mars mission. An Artificial gravity research station with a variable rotation rate could provide that information Right now for a Mars mission we are looking at sending men for a prolonged mission to a gravity environment that we don't have any health data on and bracketing that with two exposures to microgravity that we do know is harmful. That is not acceptable. A list of the adverse effects of microgravity can be found at http://www.permanent.com/s-nograv.htm

j05h · Oct 30, 2005

if we're talking a system that sends several racks up, a IRDT (inflatable ballute) could be used to bring single racks back down. The ESA is fairly far along in developing IRDT, minus troubles w/ Russian launchers. The ballute could allow for a tailored reentry, possibly more benign than Shuttle reentry for proteins, electronics and crystals. ISS should continue as a research facility, it should be creatively brought to Completion. Ideally, it would become a working partnership with other industries helping support it - pharma and tourism for now. However, I also think we will soon need a 28.5 degree station for assembly and fuel storage. Josh <div class="Discussion_UserSignature"> <div align="center">We need a first generation of pioneers. </div> </div>

shoogerbrugge · Oct 30, 2005

I think the ISS can be a real interesting space venture to study. Spaceflight is expencive, so study the current object how to run it cheaper. In such way you can learn a lot about the nature of costs of spaceflight, and thus prevent other financial debacles. Ow, and the last failure of the IRDT was a spacecraft failure, it probable overshot the landzone and is among the fishes now. The rocket went nominal this time.

spacester · Oct 30, 2005

Well orrery isn't online yet I guess so I can just be a regular poster here, cool for me but it makes for a long post for y'all.

"We need to be working on artificial gravity. " Actually I don't think so. Everything I have heard is that micro-g is not a serious or insurmountable issue for a Mars mission. However, radiation shielding, regenerative life support, maintenance and repairs in long duration, logistics etc are all the big hurdle. I may be a wild-eyed optimist, but I'm also a cynic. I just try to set the correct sub-set of my real-life cynicism aside to make a spacester post. I mention this because this is a critical issue for me, what is the truth here? My cynicism informs me that those who say micro-g is non-mission critical for man to mars are "chanting the party line" as preached by NASA. NASA preaches this because they have to given the circumstances. IOW the reason all those other problems are touted over micro-g is that ISS has almost nothing to do with developing a spin-g craft. Please note the 'almost' in the prior sentence. Those other challenges are also important, but hey, as Jon said, there are non trivial engineering issues associated with spin-g, and those issues will interact with the design of the solutions to those other challenges. So do we need to design a spin-g ship or not? I did some research, I'll post these links and my conclusions for the umpteenth time . . . (copy and paste below) . . . the fact that I see no need whatsoever to change anything in a four-year old post is proof that spin-g research is badly neglected . . . *** For tons of information on the realities of artificial gravity, see: This discussion about the effects of micro-g and the issues regarding artificial gravity and <div class="Discussion_UserSignature"> </div>

dobbins · Oct 30, 2005

One point here, there is a wide spread assumption that a station would use 1 g gravity. Once we start researching it we may find that some figure less than 1 g will solve the health problem. We might not need to have 1 g for a station or a Mars mission, just a figure that prevents the adverse health effects of microgravity.

spacester · Oct 30, 2005

Yes, I like a 38 meter radius ship spinning at 3 RPM to simulate a Mars gravity field without causing more stress from Coreolis forces than we find acceptable. That's my best guess, but we of course need to do some research to find out what the true numbers are. <div class="Discussion_UserSignature"> </div>

spacester · Oct 30, 2005

[Shameless Plug] BTW, I have worked out the rough design of a Mars Cruiser. It uses a booster stage to push a central hub to which are attached two “spokes” in the form of cross-braced triangular trusses with a man-tube down the middle. There are Bigelow habitats at each end of the trusses, with an airlock in the ceiling. The hub is a pressurized mechanical room, and on the opposite side of the hub (from the booster stage) is a pressurized storage vessel. I think America needs to build some version of such a craft and put it in LEO with an EELV or two and do some research. That appears to be pretty unlikely at this point but hey, I said America, not just NASA. This is one of the three big projects we want to tackle at ACCESS Space Foundation. We have a brand-new set of bulletin boards – The Community Section - where I’ve organized things so that a group of people can design their own space program(s). Maybe it’s all play-pretend, maybe not. We’re gonna “fake it til we make it”. Maybe it’s for real and we will actually build what we say we want to build, who knows? The point is to present alternatives to the Powers That Be (PTB) in these things, alternatives from the space advocate community, a comprehensive space strategy with technical credibility that they can draw from for their government and big business driven program. Even a play-pretend space program can make a difference. And who knows what will actually happen . . . ? [/Shameless Plug] <div class="Discussion_UserSignature"> </div>

dobbins · Oct 30, 2005

For a gravity research station we need length rather than radius. A rail type station with a habitat module that can be positioned at different points on the rail to simulate whatever radius is being tested and thrusters to set up whatever spin rate is needed for the position of the habitat module. This would allow for anything from Lunar gravity to near Earth gravity to be simulated for a variety of possible sizes for a future station.

spacester · Oct 30, 2005

Wow, such a design would give us tremendous operational capability and the research would be very comprehensive. I like it. So the module would run along the rail, with a counterweight at the terminus? The spin center would shift in the direction of the hab as the hab is moved outward. The dynamics might be tricky, but they might be just fine, hmmmm.... I like it! What I've described is the Mars Cruiser configuration, but your design concept is much better targeted at getting answers from the research. Here's the thing on that for me though: I think everybody's going to be just fine living in G = 0.38 @ 3 RPM. So I want to take a shortcut. I want to explore your concept some more, maybe the shortcut is unwise after all. (Then again maybe not <img src="/images/icons/laugh.gif" /> ) By 'length rather than radius', let me check your meaning. I use 'Radius' because the equations use an 'R', but the dimension of the trusses in my design would be 'L' for Length. This length would be less than the R = spin radius by half the hub diameter if the effective spin radius is taken as the ceiling of the habitat. So we're talking about the same 'length' here, right? Your length is from the spin center, and you want to use 'length' to express the fact that it is variable, as opposed to the fixed radius of my design? edit: Oh boy, orrery is here, gonna put on a different hat now. I haven't read his post yet, this should be fun . . . <div class="Discussion_UserSignature"> </div>

barrykirk · Oct 30, 2005

Instead of a rail.... How about a tether? The tether could be on a reel and just wound or unwound to adust the distance between the counterbalance weight and the habitat. Of course everybody knows I just love to throw tethers around. LOL

dobbins · Oct 30, 2005

I'm not thinking of operational capability as much as gathering data. It's an X-plane type concept. X-planes aren't intended to be operational craft, just test beds to get the data to build future craft that will be operational. It would be the X-number space station. Basically its a movable habitat on a stick with a counter weight at one end. The stick would have to be as long as the longest station radius you want to test for, say 100 meters. The habitat could be positioned anywhere on the stick. If you wanted to test the effects of a 75 meter radius station with a 3 RPM spin then the habitat module would be positioned at 75 meters from the counter weight and the station spun to provide the 3 RPM spin. Then you could move the habitat section in to test for Martian level gravity at a 3 RPM rate. It would give the ability to test for a variety of proposed station sizes and spin rates so that a data base could be built up for use by designers of future operational bases and interplanetary ships. There wouldn't be any guesswork involved in these designs, the engineers would have hard data to work with in deciding the radius and spin rate. It's also would be considerably cheaper than designing a full fledged operational station and then finding out the the assumptions about gravity level, spin rate or size were incorrect.

dobbins · Oct 30, 2005

A Tether might work too, provided that it doesn't cause any problems with slack when the spin rate is being set. A Rail is just a more conservative approach. The important thing isn't if it's a tether or a rail. It's having a station that can test a variety of possible parameters.

barrykirk · Oct 30, 2005

Yes, I agree, that sort of testing needs to be done. We already know what happens to people in micro-gravity. But a sustained source of lunar gravity and or mars gravity in LEO would be a fabulous test bed for long term biology studies. It would be much easier to build spin gravity into a structure in free fall. Very difficult to augment lunar or martian gravity on the surface with spin gravity. Nobody knows yet the long term effects of lunar or martian gravity. Dobbins, your absolutly right. That sort of research needs to be done. I just mentioned tethers cause I'm fixated on them. Also, it might be cheaper and possibly simpler than a rail. But as you pointed out, a rail is a more conservative approach and more likely to work. It does provide rigidity in more than just the tension direction. I'm sure that somebody will perform an experiment just like that. It remains to be seen what approach is used. It could be tether, rail, or something else.

spacester · Oct 30, 2005

Let’s see, I think I’ll take it paragraph by paragraph rather than just grab the stuff I think I can make points on. Par. 1: Very clearly stated, thank you. You’re preaching to the choir on moving NEAs up on the list of priorities. NEAs are my first love in space advocacy. There is no reason extant why they are not a valid near-term proposition for exploitation. But that’s another subject. Par. 2: I basically agree with your overall assessment, but with a critical difference, please see the next paragraph. Par. 3: That ISS will become obsolete because of the presence of Bigelow facilities is a fallacy. ISS is going to have tremendous capabilities that Bigelow will not provide. So it’s a comparison between a science lab and a garage. Sure, Bigelow will have a HUGE cost advantage, but there will be capability on ISS that will not exist elsewhere, and vice-versa. The existence of one thing does not obviate the usefulness of another thing. Bigelow will be providing the garage, the tenants will bring only the equipment they need and no more. Nothing will have the capability of ISS any time soon. Yes it will be one of many stations if things go well, but so what? It will have value. Par 4: Silly error here, the ‘rocket fuel’ and oxidizer are actually cheap. But yes, STS is very very expensive. Par. 5: Um, you lost me halfway thru. I like the talk about what the station was about, in terms of shaping the debate as to what ISS is good for. But the mission accomplished and mars plan stuff sounds like crazy talk to me. Develop the life support on the way? Hello? Par, 6: OK, back on track, you’re preaching to the choir here in fact. I’m the champion of going at the earliest possible time, of figuring out ways to do it sooner yet safer. But I lost the connection to ISS. Ah, wait, I get it. It’s the competition for the money, right? Well, I have an http://www.accessspacefoundation.org/s_overview/abunda</safety_wrapper <div class="Discussion_UserSignature"> </div>

dobbins · Oct 30, 2005

"once a Bigelow station were to become operational" Throwing away an existing station because of a hope that Bigelow will somehow translate words into hardware isn't a wise policy. I Hope Bigelow and Space X succeed, but until they actually show that they can put something into space and make the profits needed to remain in business by doing it then I will remain a skeptic.

dobbins · Oct 30, 2005

A Few years ago NASA also could have invested in a number of dot.coms that would have promised them huge profits. Could they build a station off the dot.com profits?

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