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

[josh_simonson]

Delta-V and ISP are used to calculate the fuel fraction needed to get someplace using the chart in the above link. In the case of going from LEO to LLO the fuel fraction is around 55% if you use a high performance LH2 engine. That means that whatever your craft weighs, it must be 55% useable fuel by mass.<br /><br />There are some slightly lower engergy paths that can be used, and higher performance electrical engines, but both take considerably longer to get to the moon - requiring more supplies and radiation shielding which negates any fuel savings. Cargo could go that route, and likely will at some point when a SEP tug is developed. I asked Dr. Stanley about this and he said such a tug was too high a schedule risk and too expensive to develop initially, though it would be attractive in the long term. That's a project that would be good to dole out to an international partner like russia or ESA. Russia pioneered SEP.<br /><br />The high fuel fractions required to get to the moon, to the lunar surface, back off the moon, and back to earth require that propulsion stages be expendible and the returning craft be minimalist until such a time as we can refuel along the way by some means. That could involve in-situ fuel on the lunar surface and fuel that is carried around the earth-moon area by SEP tugs that are highly efficient but painfully slow. Unfortunately, we can't produce in-situ fuel until we send some missions to the moon to find a likely source and then a bunch of equipment (outpost stage) to extract it. That's as far as ESAS goes at this point. Once at the outpost stage, many upgrades are possible. <br /><br /><br /><br />X-33 was cancelled because it was over-budget and having technical problems. Also at the same time the launch market that venturestart was intended to serve imploded with the tech collapse. With the program overbudget, and no customers on the horizon, the program was doomed. The current state of affairs is that the EELV rockets cost al

 

[specfiction]

>"Delta-V and ISP are used to calculate the fuel fraction needed to get someplace using the chart in the above link. In the case of going from LEO to LLO the fuel fraction is around 55% if you use a high performance LH2 engine. That means that whatever your craft weighs, it must be 55% useable fuel by mass."<br /><br />Yes. And the fuel fraction from Earth's surface to LEO is about 90%, but for a much larger mass (in order that it be useful once in orbit) than one we'd be sending to the moon. So the actual mass of fuel to LLO is much smaller than that required to get to LEO in any useful way.<br /><br />Above, from the same info, one can compare energy budgets. For a craft 20% the mass of the one to LEO, one requires approx 8% the energy (of the larger craft from the surface to LEO) to LLO (not landing).<br /><br />Just as a matter of interest, VentureStar stated they could get payload to LEO at a rate of $1K/1lb. What is the rate for current expendable rockets with nonreusable cost factored in and comparing apples to apples, i.e. rates for a rocket not expected to carry people, and one reliable enough to mitigate risks of carrying people?

 

[nacnud]

<font color="yellow">If you don't mind my changing the subject a little, does anyone know exactly why the X-33 was cancelled?<br /><br /><font color="white">Try this, X-33/VentureStar - What really happened</font></font>

 

[tomnackid]

If we were staying with the basic shuttle system I would say we would HAVE to develop the Shuttle C to have any kind of real chance at doing anything beyond LEO with a price tag that Congress would go for. Unfortunately either throwing the SSMEs away or developing a reusable reentry pod and recovery system for them ends up costing almost as much as developing a true HLLV and for less payload (side mounting always brings a big penalty with it).

 

[CalliArcale]

<blockquote><font class="small">In reply to:</font><hr /><p>Yes. And the fuel fraction from Earth's surface to LEO is about 90%, but for a much larger mass (in order that it be useful once in orbit) than one we'd be sending to the moon. So the actual mass of fuel to LLO is much smaller than that required to get to LEO in any useful way. <p><hr /></p></p></blockquote><br /><br />Bear in mind, of course, that although we can assume that at least on the second flight the lunar lander need not be counted in liftoff mass, its fuel will have to be counted. The 55% fuel fraction will still have to be lifted to LEO, by even more fuel. (Plus any other logistics and the crew themselves.)<br /><br />In my opinion, the real benefit to using LEO is not fuel savings, at least not directly. It's the fact that your lunar lander can be reused, mainly by virtue of it not needing a reentry module. The movie "2001" depicted the usual concept for this sort of thing: reusable spaceplane (which the book explains has a reusable flyback first stage -- basically a hypersonic carrier airplane) docks with space station and offloads crew. It returns to Earth at leisure. Reusable lunar lander picks up crew, departs space station and goes to the Moon. Basically, you get two shuttles: the Earth-LEO shuttle and the LEO-Moon shuttle. The savings is not really fuel. The savings comes in divorcing the lunar spacecraft and the Earth reentry spacecraft, so you're only using the bits you need for the particular part of the mission. But that was viable in "2001" because they were running regular flights to and from both the station and the Moon already -- volume is what makes reusability worthwhile. <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>

 

[specfiction]

Thanks for that reference to the unbelievable incompetence and lack of vision of those who set the agenda for manned space. Until we can get some decision makers who understand science and innovation we will go absolutely nowhere in manned space.<br /><br />That is why, if I were a NASA engineer or scientist, I would be praying for someone like Rutan to succeed. Only under pressure from real innovators will an agency like NASA decide to hire and/or promote real talent within its ranks. And for those reading this, I’m not talking about the very fine technical staff at NASA, I talking about the idiots in charge at the highest levels.<br />

 

[nacnud]

Sad isn't it. While I don't think that the X-33 realy would have turned out to be cheaper that a back to basics ELV like Soyuz or maybe SpaceX's vehicles, if it had flown at least we would have by now actual data on the concept.

 

[specfiction]

Yes--I agree. And the only thing that will drive volume is a viable business plan whether it be for manufacturing, energy, tourism, all of the above plus many other things. Unfortunately, none of this has been thought out in a bold and realistic way.<br /><br />I believe the people in charge are not capable of doing this.

 

[specfiction]

>Sad isn't it. While I don't think that the X-33 realy would have turned out to be cheaper that a back to basics ELV like Soyuz or maybe SpaceX's vehicles, if it had flown at least we would have by now actual data on the concept. <br /><br />Yes. I couldn't agree with you more. The X-33 as well as the Shuttle were great, innovative concepts by very talented technical groups. It's called development. I've been in charge of R&D and I can tell you I've never seen a concept, that was built, and performed as predicted. Only after a careful, long term iterative program of development can one realize the true benefits of an innovative design.

 

[josh_simonson]

No matter what size your LEO craft is, it must be at least 55% fuel to get to LLO. It may only be 7 or 8% of the rocket on the pad, but it still uses more than half of the rocket's capacity. <br /><br />A breakdown of launch costs is here: http://www.futron.com/pdf/FutronLaunchCostWP.pdf<br /><br />Soyus $2400/lb<br />Zenit $1500/lb<br /><br />Both of those are based on only a handful of launches/year. Venturestar did not have sufficient market to launch often enough (50x/year) to achieve their claimed launch costs assuming the program came in on budget by some miracle (which the overbudget x-33 cast serious doubt upon). Space shuttle made similar cost claims that turned out to be optimistic by an order of magnitude.<br /><br />If zenit were launched 50x/year, the cost/lb would definitely be less than $1k. Even the EELVs might beat $1k/lb if they were launched that often - and the development costs are already paid for. That's a true apples/apples comparison.

 

[specfiction]

Yes. This is an argument against the viability of an Earth surface to moon strategy. Sure, you can do it with a least-common-denominator technology, but in the long run, it's as dead as the dinosaur it is.

 

[willpittenger]

<blockquote><font class="small">In reply to:</font><hr /><p>I'm a big fan of the 'tank swap' instead of pumping fuel between tanks.<p><hr /></p></p></blockquote><br />I have said, and will say again, swapping fuel tanks in orbit is dangerous. If nothing else, it requires a spacewalk. Space inside a habitable volume will always be too precious for tanks. <br /><br />Also, the station (or lunar lander) must also transfer oxygen. Crew and fuel cells both have a tenancy to appreciate that. <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>

 

[willpittenger]

I am liking the following:<br /><br />* Landers would be divided into three catagories: Cargo (with detachable cargo containers that can be lowered to the surface), Crew (single stage that can refuel from a fuel factory; holds enough fuel for one round trip starting at the surface), and Crashers which supply an emergency supply of fuel and other cargo. The crashers also supply the initial supply of oxygen. Later supplies of fuel, oxygen, and water would be made from the lunar regolith.<br />* Initially several landers of each type are sent ahead and land.<br />* The fuel factories (along with those for oxygen and water) begin their work.<br />* When a lander is fueled, the first mission begin.<br />* Upon entering orbit, the CEV calls for the lander to enter orbit and dock.<br />* Similar processes happen if the cargo-only landers are needed. They dock to a cargo container attached to the CEV. The CEV then undocks from the cargo container. The cargo lander is then able to return to the surface and lower the container to the ground.<br />* The crew lander then lands with the crew.<br />* The first mission is short and is mainly to check everything out.<br />* Later missions have more detailed plans.<br /><br />Because the crew lander does not have a decent stage, it does not need an elevator. <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>

 

[j05h]

>I have said, and will say again, swapping fuel tanks in orbit is dangerous. If nothing else, it requires a spacewalk. Space inside a habitable volume will always be too precious for tanks.<br /><br />I'm talking about an automated system to swap tanks - has nothing to do with human spacewalkers and everything to do with the ESAS trade studies. I'm to busy to dig up any links, but one of the proposed architectures involved automated tank swapping as a way to enable all sorts of beyond-LEO projects. No astronauts needed. <br /><br />The kind of roadblock you propose is a strawman.<br /><br />josh <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>

 

[tomnackid]

But the major point is why should we wait around another 30 years to develop on orbit refueling, RLVs, etc. etc. just to explore the moon and Mars? Did Lewis and Clark wait around for paved highways and railroads? Obviously Jefferson knew that the Louisiana territory would not be developed by guys with birch bark canoes and mules, but that didn't mean it had to sit there unexplored. VSE is about EXPLORATION not development people! If private industry thinks there is anything out there worth exploiting they will build the infrastructure to their specifications. NASA is about exploration and R&D not mapping out a planned space economy.<br /><br />And for those who complain that VSE is "just redoing Apollo" even if it were an exact duplicate of Apollo it would still be a major accomplishment (probably a greater achievement than anything any of you have been involved with!). Apollo was never completed. 12 men on a body with a a surface area of 14,658,000 square miles hardly qualifies as thorough exploration! It is the hight of arrogance to think otherwise.

 

[marcel_leonard]

I don’t know why you’ll are all so hung-up-about some type of orbital refueling; if only to change the subject of utilizing the shuttle/ISS as an integral part of returning to the moon, and going on to mars. Why is it that when we have for the first time in the history of man we have actual resources stationed in orbit; the best we can come up w/ after close to 40 years since our last lunar mission is an elaborate repeat Apollo mission? <div class="Discussion_UserSignature"> "A mind is a terrible thing to waste..." </div>

 

[j05h]

> I don’t know why you’ll are all so hung-up-about some type of orbital refueling; if only to change the subject of utilizing the shuttle/ISS as an integral part of returning to the moon, and going on to mars. Why is it that when we have for the first time in the history of man we have actual resources stationed in orbit; the best we can come up w/ after close to 40 years since our last lunar mission is an elaborate repeat Apollo mission?<br /><br />ISS is in the wrong orbit. I"m not an orbital mechanics guy, but all the ones I've discussed this with say it's in the wrong orbit. You're trying to turn a microgravity research station into an assembly bay, and it doesn't work. Have you noticed how far they've descoped ISS in the past few years? No cupola, no centrifuge, no science & stowage platform on the russian side, etc. It's not going to be the platform that interplanetary missions stage from. The same way it won't produce commercial freefall silicon chips or pharmaceuticals. It's not meant for those tasks. You don't use an oxen team to sail the oceans.<br /><br />We need launch sites, fuel depots and new stations in equatorial areas and probably at 28 degrees from Cape Canaveral. SpaceX, Ariane and SeaLaunch all can launch to equatorial LEO right now. A rough architecture that makes sense would include payloads that can fly on multiple launchers, flown to an "industrial park" orbit in LEO. This is a cluster of space stations from various interests running in equatorial orbit. It would include tank farms, recycling facilities, hotels, assembly "hangars", etc. The manned facilities might be docked to the tank farm (shielding) with various foundries, silicon refineries and other freefall products. This set of facilities saves every piece of equipment flown up, some is recycled and the rest is used to bootstrap a second coplanar industrial park in Highly Eccentric Earth Orbit (HEEO) or one of the LaGrange points. This facility is mostly tank farm, it receives reso <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>

 

[marcel_leonard]

Here is the thing you have to remember about the ISS, Shuttle, Mars, and Moon projects. Each one of these NASA/ESA projects brings with it four separate billion dollar budgets. In my opinion anytime you can combine projects under a common objective, and unified goal we can save, and free-up money that ultimately will pay for the cost of a permanent bases of operation on both the Moon/Mars… <div class="Discussion_UserSignature"> "A mind is a terrible thing to waste..." </div>

 

[j05h]

Operational experience of the ISS shows that international, governmental cooperation on large space projects increases costs. Mir's earlier years and the US "Freedom" project were roughly on budget until we started cooperating. It's much more expensive to operate across so many time zones, language and technology barriers. A better question than cost savings is whether the added expense is worth the additional reward? Yes, in my opinion. <br /><br />The proper organization to develop the LEO "industrial park" is a purpose-created Port Authority with enough financial backing to simply purchase the majority of their equipment. In terms of infrastructure, a LEO setup like I describe is a big project, but not unheard of (Big Dig, Panama Canal). In this context, NASA (etc, RKS, ESA) would certainly provide technology and personell. All equipment would be purchased on the open market to help develop mass-manufactured space hardware, with select in-house development. Funding could be public-private or purely private - the difference becomes blurry at certain funding levels anyway. The operator would provide habitable volume, storage, plug-in space for new modules, volatiles, security and traffic control. They would encourage new services and the fact of facility construction would drive the rest of the development (freefall pharma, chips, ISRU, SPS).<br /><br />There is a company called Space Resources Inc that presented at ISDC. Their plan is very similiar to described, they are trying to aggregate customers together to achieve an economy of scale by flying so much payload to one destination. The model is very similar to building/operating a port or like the Hudson Bay Company. Jim Schulz of SRI described it as there is no one "killer app" that will make human spaceflight common, but there are many unique applications that can be combined to make it happen.<br /><br />Here's my deal on the future of space stations, and our place in the cosmos. When we're ready, it will happen. <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>

 

[marcel_leonard]

<i>"Operational experience of the ISS shows that international, governmental cooperation on large space projects increases costs."</i><br /><br />Just because you say it does; doesn't make any more so!!!<br /><br />If anything now that the ISS is completly being supported from Moscow w/ Soyuz buses; this should make us here in the west re-evaluate what the hell are we doing with our dollars here in this <b>Metrically Challenged Country!!!</b> <br /><br />I for one say combine all of the budgets... <div class="Discussion_UserSignature"> "A mind is a terrible thing to waste..." </div>

 

[qso1]

marcel_leonard:<br />Here is the thing you have to remember about the ISS, Shuttle, Mars, and Moon projects. Each one of these NASA/ESA projects brings with it four separate billion dollar budgets.<br /><br />Me:<br />In an ideal world, international cooperation would be more economical but, in the real world, this has not proven true as we have shouldered the bulk of ISS expense. Even if we did save money, those savings would not necessarily go towards other space projects, politics and our government budget allocation process simply do not work that way. <div class="Discussion_UserSignature"> <p><strong>My borrowed quote for the time being:</strong></p><p><em>There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened.</em></p> </div>

 

[marcel_leonard]

What does that have to do w/ combining the budgets? <div class="Discussion_UserSignature"> "A mind is a terrible thing to waste..." </div>

 

[j05h]

This is getting wicked far offtopic, but let me continue anyway. <br /><br />QSO is totally correct about the govt. budget process. Spreading that around through several govts only amplifies the problem. It produces interesting results, though. There was a lecturer at ISDC, she was a Russian translator for Tech Transfer, Inc. TTI provides central translation and knowledgebase for the entire ISS project, including an entire English-Russian technical lexicon. Very interesting and wouldn't exist without ISS cooperation. However, TTI and the rest of what makes ISS possible is extremely expensive. <br /><br />Compare this to (per Buzz Aldrin's recent analogy) a modern jetliner. The hull is made in Italy (by the same peeps that build MPLM and Destiny shell) the engines around the US, the electronics are from Taiwan and the fabric on the seats made in Bangladesh. And yet, put together in the right way, this all makes a jet aircraft that makes money. The jet or ocean-going ship models are what we should be working towards for spaceflight. <br /><br />The expense we are talking about is government cooperation (and cost-plus contracts) not international transactions, per se. <br /><br />Josh <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>

 

[marcel_leonard]

<i>“It produces interesting results, though. There was a lecturer at ISDC, she was a Russian translator for Tech Transfer, Inc. TTI provides central translation and knowledgebase for the entire ISS project, including an entire English-Russian technical lexicon.”</i><br /><br />The English-Russian technical lexicon as you call it; is what I call the <b>Metrically Challenged Country</b> called America. If science and engineering PhDs at the JPL can make the mistake of forgetting to do the conversion from miles to kilometers and as a result losing a 40 billion dollars Martian probe; just imagine how many trillions of dollars we are losing on a daily basis every time a cargo freighter docks in New York, Miami, and San Francisco bay from the global metric lexicon? <br /> <div class="Discussion_UserSignature"> "A mind is a terrible thing to waste..." </div>

 

[j05h]

> The English-Russian technical lexicon as you call it; is what I call the Metrically Challenged Country called America. If science and engineering PhDs at the JPL can make the mistake of forgetting to do the conversion from miles to kilometers and as a result losing a 40 billion dollars Martian probe...<br /><br />Troll. How's life under that bridge? <br /><br />Josh <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>