New ESAS warns VSE is becoming 2-man, 7-day Lunar missions

[josh_simonson]

Electrolysis takes a lot of energy, but since they're planning only 1 or 2 missions a year, it can take 6-12 months to finish the electrolysis. The longer you can wait, the less power you need. One ISS array (it has 4 at 19.5kW each) could electrolize about 50,000lb of H2O/year. That's enough fuel for two missions for the LL2 depot. I got that from this page http://www.nrel.gov/docs/fy04osti/36705.pdf using the yearly H2 production numbers and multiplying by 8 to count the O2 as fuel as well as the H2. One ISS solar array weighs 3300lbs. All four arrays could produce enough fuel to fill 2 EDSs/year in LEO.<br /><br />Too bad the ISS is in a lame orbit or the fuel depot could use it's solar farm.

 

[starfhury]

Building an RLV is hard work, but we only have to design and build the first successful one and then we have a template to build others from. At some point we still have to build one. I am still convinced that the problem with any RLVs begins and ends with the propulsion systems. We need a powerful, yet compact safe and efficient propulsion system to make any of this work. It might cost us a hundred billions dollars in inital development cost over a decade or so, but once we have it doing most other things becomes significantly easier.<br /><br />Anathema is it might be, we still need to explore non chemical options such as nuclear power. Nuke power has the environmental and thrust to weight ratio issues that still needs to be worked out. But right now we have explored maybe 80 to 90% of what chemical rockets can do and maybe 20 -30% of what nukes can do. My idea would be an AN-225 and a 727 sized nuke powered RLVs with wings! Why? The same reason an AN-225 has wings. It's thrust to weight ratio is below or close to 1:1. Wings have no use once in space, but this RLV need them because of the lower thrust to weight issues with nukes and its operating environment. <div class="Discussion_UserSignature"> </div>

 

[josh_simonson]

Other than tourists, there are no customers for an RLV though. Increasing supply (in this case launch services) to foster a market is not the right way to do it (economists call this 'voodoo economics'), rather the best way to grow the industry is to foster demand. We can cut the EELV costs in half just by using them more, what's the point in an RLV when our existing launch capacity is sitting idle? The re-useability of SpaceX's rockets is more than enough for the current launch market.<br /><br />Launch costs are only about 1/3 of the expense of space - there's plenty of room to trim fat in the other 2/3 that doesn't involve something as big and complex as an RLV.

 

[vt_hokie]

How much demand for railroad travel was there before the steam engine was invented?

 

[starfhury]

I think we are missing the point. Air lines do not operate at full capacity. Railroads don't operate at full capacity all the time. Each time a satellite is to be launched, a whole new expendable rocket has to be assembled just for it. Never mind that it's called a Delta IV or Atlas V, it's a whole new vehicle each time. On top of that, you can't launch it when you want to. But the thing is we want to get beyond satellites only. And if you're planning to launch components for an orbital resort, the costs has to come down. Doing it on expandables in this way is just too costly. <br /><br />As an example, if Bigelow needed to launch 10 50,000 lbs modules on expendables, it's going to cost at least a billion dollars at 100 millions a pop on an Atlas or Delta V. It's going to take months to build each Delta or Atlas so not only do you lose time it cost a ton as well. If we separate the RLVs development cost from each actual launch cost, with a week or two week turn around time the picture changes. You don't need to plan things years and years in advance. Bigelow would be able to launch it's 10 modules on two RLVs within 10 weeks times. Thus their time to market would be faster as well as their return on investment. <div class="Discussion_UserSignature"> </div>

 

[j05h]

>> How would a fuel depot deal with boil off issues?<br /><br /> />One interesting approach is to ship water and use solar panels to generate electricity to separate the water into hydrogen and oxygen. I am sure there are showstoppers in the plan, but I do find it interesting.<br /><br />Water makes handling much easier. Fuel depots can be insulated once installed and reliquification makes sense on a larger facility. Boiloff can be minimized and used in processing. <br /><br />Josh <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>

 

[frodo1008]

A couple of things here:<br /><br />One, indeed with a currentcy that is exchanged for less than 0ne-tenth what the dollar is, the Russians can do a great deal more with a lot less than any American group (private or NASA) can.<br /><br />Two: While they may not be directly lying here, they could very well be stretching the truth to get additional envestment. Like, our people don't do that, right?<br /><br />Three; They are stating their price (that I believe to be way under funded) for going around the moon. What NASA is talking about is landing ON the moon! Two very, very greatly different things here!<br /><br />Did you think these things through before you bothered to post?<br /><br />

 

[frodo1008]

Hey wow! Congratulations! You have actually performed a very useful function this time.<br /><br />While Bell is sometimes a negativist, he does make a whole lot of very good points in his article here!<br /><br />It turns out that he has far more sense than I would have given him credit for. Thanks for the link!<br /><br />His most negative points seemed to be aimed at Dr. Robert Zubrin and the Mars Society. While I do have a great deal of respect for Zubrin for at least his truly great idea of living off the land on Mars itself, I do have a lot of misgivings about most of his other points (like Bell has).<br /><br />The main ones for me are Zubrin's almost humorous price estimates for going to Mars! It is going to cost at least as much to place human beings on Mars as either the Apollo, shuttle, or ISS has cost! This is $100 billion at the very least, and quite possibly double this amount!<br /><br />For me at least the very idea of placing some 4-6 people into a single spacecraft for the length of time and hazards of such a voyage is an open invite to disaster!! There will be NO Apollo 13 type of rescue of these people. They will be millions of miles from the Earth and totally on their own! <br /><br />I would think that the only possible way to insure mission success in this voyage would be to have enough spacecraft that if one (pr possibly even more) such craft are totally disabled that the people on that particular craft would be able to transfer to other craft(s) and continue on! Perhaps someone like Bell could appreciate what I am saying here, but most of the Mars Cadets will condemn me as being far too negative.<br /><br />We should even have long term studies done at the gravity levels of both the moon and Mars on spinning space stations similar to the type proposed by Wherner Von Braun (who also thought the we should have multiple craft to go as far out as Mars and beyond) proposed all the way back in the 1950’s!<br /><br />

 

[spacefire]

actually, for a short duration mission to the lunar surface, the hardware requirements are minimal. <br />See SpaceDev's rocket chair proposal. There's no re-entry to worry about, no shielding is thus required. The astronaut's suit can provide the life support and consumables. <div class="Discussion_UserSignature"> <p>http://asteroid-invasion.blogspot.com</p><p>http://www.solvengineer.com/asteroid-invasion.html </p><p> </p> </div>

 

[radarredux]

> <i><font color="yellow">And you want somebody to put human beings on the moon for some $200 million per each! ... Can you please stop it with the humor here!</font>/i><br /><br />I think putting someone on the moon for $200 million is very reasonable. Getting someone on the Moon <i>alive</i>, much less returning him or her safely to the Earth is a different story. <img src="/images/icons/smile.gif" /><br /><br />On a more serious note, if a good infrastructure is in place on the Moon, and enough flights are generated so economies of scale kick in, $200 million might be reasonable.<br /><br />For example, if you have a very inexpensive means to move a human from Lunar orbit to the Lunar surface (e.g., the lawnchair with rockets approach), and you have an efficient and established life support system on the Moon (e.g., a habitat with high-level of recycling already operational), then the primary cost is getting the human into Lunar orbit -- not unlike the Russian $200 million offer.</i>

 

[publiusr]

I just hope that CaLV gets built. This still beats ISS style assembly in launching 5 to six Delta IV heavies when it takes 2-5 years between their flights. Shuttle does better than that.

 

[bwhite]

Visualize a re-useable LSAM, perhaps even with RL-10 class engines (2 or 3). Visualize lunar LOX production and an L point Gateway station. <br /><br />Travel between L1 or L2 and the lunar surface is merely propellant cost and amortized infrastructure cost.<br /><br />Travel to/from LEO & L1 or L2? One Soyuz and One Proton. <br /><br />One additional Proton delivers the fuel (H2 or CH4) to the L point for the landing module.<br /><br />$200 million per person? $600 million for three? <br /><br />Piece of cake.

 

[JonClarke]

"Perhaps someone like Bell could appreciate what I am saying here, but most of the Mars Cadets will condemn me as being far too negative. "<br /><br />Yep you are being too negative. Also unrealistic. Sending multiple spacecraft to Mars increases risks, not decreases it. Doubling the number of spacecraft increases the costs by at least 150%, more likely 200%. Is this what you want? But this is a subject for another thread.<br /><br />Jon (Mars cadet) <div class="Discussion_UserSignature"> <p><em>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</em>  Arthur Clarke</p> </div>

 

[frodo1008]

You are correct in that this should be on another thread.<br /><br />But you are incorrect in that redundancy does NOT increase risk, it would be the only thing that could be done to reduce risk if you are some 100 million miles from the Earth!. <br /><br />You are correct in that it would indeed increase cost, but as Zubrin's estimates are only about a tenth of anything reasonable anyway. then such increases should be quite easy to handle!

 

[JonClarke]

Newsartist is correct. If you have two spacecraft, each with a 1% chance of failure, sending two will result in a 2% chance of failure. If the chance of failure is 2% the chance of losing one spacecraft on a two spacecraft mission is 4%<br /><br />Furthermore, historically the most dangerous part of a mission are launch and entry. Redundant spacecraft do not provide any assistance what so ever at these points. <br /><br />The only part of the mission where they can provide any support is during the least dangerous part - the Martian surface and the interplanetary transfer. Furthermore, as the main purpose of having redundant spacecraft is to guard against catastrophic failure can can only be used once. <br /><br />The place for redundancy is within an actual spacecraft, where you have backups for every mission critical item. Not by providing a second spacecraft.<br /><br />As for your contempt of Zubrin's cost estimates, as I understand them they are quite roboust, given the underlying assumptions, and have certainly stood up to independent analysis. The cost BTW was ~20 billion in 1990 terms, which, adjusted for inflation is ~$40 billion in today's terms. Even if your $100 billion estimate is correct, Zubrin's figures are not out by a factor of 10.<br /><br />Jon (Mars cadet) <div class="Discussion_UserSignature"> <p><em>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</em>  Arthur Clarke</p> </div>

 

[josh_simonson]

That depends on how you look at it.<br /><br />If you send 2 completely redundant spacecraft, then your odds of losing one double, but the odds of complete failure are the odds of failure^2.<br /><br />Still, it's probably more efficient to make a single spacecraft with redundant systems, say engine out capability on the ascent stage. The tank probably won't fail, the seats won't fail, neither will the windshield... You really only need duplicity in the parts that are likely to conk out - engines, fuel lines, avionics, ect.

 

[tap_sa]

<font color="yellow">"If you have two spacecraft, each with a 1% chance of failure, sending two will result in a 2% chance of failure. If the chance of failure is 2% the chance of losing one spacecraft on a two spacecraft mission is 4% "</font><br /><br />Umm, no. Chances that both spacecrafts don't fail is (0.99)² = 0.9801 and chances that both of them fail is (0.01)² = 0.0001 . Chances that one of them fails is what's left when previous probabilities are substracted from one ie. 0.0198 .<br /><br /><font color="yellow">"historically the most dangerous part of a mission are launch and entry. Redundant spacecraft do not provide any assistance what so ever at these points."</font><br /><br />Mars flotilla probably launches from orbit. Should one of the craft malfunction during burn and shut down it's engines the other one can do the same, crew transfers to working spacecraft which then resumes the burn. Otherwise the crew in the broken vehicle might get stranded into orbit where they'd perish after running out of supplies. Similar situation when flotilla leaves Mars.<br /><br />Even during 'safe' transfer stage it's nice to have another vehicle near you if nasty meteoroid renders your heatshield/reentry capsule/propulsion inoperative.<br /><br />

 

[gunsandrockets]

"Major weight problems. Only one that works is a two-man LSAM, called the "Walmart" lander."<br /><br />www.nasaspaceflight.com has retracted the story.<br /><br /> <br /><br />

 

[shuttle_rtf]

I pre-empt my pulling of the article on page three of this thread.<br /><br />Boiled down...due diligence (we didn't know just how sensitive and how very internal those scans were - and we're not in it to p--s NASA off and hurt on-going studies). <br /><br />Because it's on-going, data changes, thus makes a report published one day, inaccurate (even just small details) the next - we're not in it to publish inaccurate info.<br /><br />Also, we're going to be following it up with some of the top people, so we'll get some much better, question and answer provoked, quote content.<br /><br />I'd rather work with NASA etc. and get some good on-going coverage, than be in the shadows, annoying them, hurting people's progress for fear of it being in the media the next day, and having to rely on leaked documents.<br /><br />So I'd rather pull content in that case, rather than to try and save face and pretend it wasn't a problem.

 

[gunsandrockets]

"Also, we're going to be following it up with some of the top people, so we'll get some much better, question and answer provoked, quote content."<br /><br />Hmm...while you're at it, maybe you could also include questions that another thread brought up...<br /><br />http://uplink.space.com/showthreaded.php?Cat=&Board=missions&Number=477901&page=3&view=collapsed&sb=5&o=0&vc=1

 

[shuttle_rtf]

Make you a deal. Think of your top question and mail me at chrisbergin@nasaspaceflight.com and I'll be happy to include it into our question sheet.<br /><br />Chris.