Re: NASA's grand plan to revive human exploration...
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If it cost more to use a disposable aircraft than it cost to service a 747 then it would make more sense to use the disposable aircraft.<br /><br />A high flight rate is what makes servicing a 747 afordable. For the foreseeable future NASA isn't going to have anything approaching the flight rate needed to make reusability work.<br />
<br />"...more to use a disposable aircraft..."<br /><br /><br />I agree, but the premise is NOT TRUE.<br /><br />you imagine a spaceplane or an orbital module like a new Shuttle or ISS... wrong!<br /><br />Shuttle and ISS was bad designed and luckless!<br /><br />don't think that a little well-made spaceplane will need multi-billion dollars servicing and repair like the Shuttle (that costs billions only to find and repair problems to avoid another crash!)<br /><br />the little spaceplane will costs MUCH LESS to build and service and will be used much more than Shuttle (and much more than CEV, thanks to its flexibility and multi-role-mission possibilities)<br /><br />an "used" space module (if well designed) simply remains in orbit waiting for next missions, why costs?<br /><br />resupply and refuel it will be (if well designed) simple and low cost like ISS Progress resupply<br /><br />we are in the "mainframe-era" of space flights (Apollo, Shuttle, ISS)<br /><br />little spaceplanes and reusable orbital modules will be the "personal-computer-era" of spaceflights: more power - more easy - much less costs<br /><br />if NASA will "think conservative" continue to build "space-mainframes", if will "think innovative" build the "space-PCs"<br /><br />
Nasa spend most of the 90's, and billions of dollars on 'spaceplanes' that never flew. They've demonstrated an in-ability to do this, and so now they've been tasked with building something that they can actually do. Their obsession with 'progress' left us in this mess of not having a vehicle now.<br /><br />The 'progress' that NASA is tasked to do is explore the moon and mars, not perfect re-entry technology for mass markets. They're using the simplest return vehicle so that they can focus on the groundbreaking technologies such as in-situ resource development and nuclear power applications for space. The CEV is a tool to accomplish the VSE - it is not the goal of the VSE. You call wings progress, but we've been doing it for 30 years, hardly new, hardly progress, to re-do something that was done 30 years ago. And if you say we can improve upon shuttle to make 'progress', we can also improve upon apollo for 'progress' - we've got an additional 10 years of experience we can add to capsules than we can to winged vehicles.<br /><br />Last - a winged vehicle cannot be used for a station lifeboat because it's TPS is unprotected from micrometeors, ect. A capsule can encase it's TPS in a shroud easilly to protect it, and has a smaller profile to reduce the odds of impact. I guess since you're sending jacuzzis up to orbit though, you can send a full vehicle shroud around your spaceplane too.<br /><br />How's a jacuzzi progress BTW? Increase membership in the 3-dolphins club?
>with its own (replaceable or refuelable) rocket engine in a joined service module (like Apollo) <br /><br />So the moon flights have to baseline producing fuel locally? Apollo dropped the SM on approach and did a direct entry - something you don't want to try with a liftingbody/spaceplane. It's something like a 36km/s velocity difference - much higher than LEO reentry. Apollo didn't reenter low earth orbit, as you suggest, but entered directly from Lunar transfer. The only burn the SM did to get back to Earth (IIRC) is the one to break lunar orbit.<br /><br />Efficiency is exactly what any space transport system needs. Dissing "efficient" shows your lack of understanding aerospace or general engineering. I'm a complete layman and it's still obvious your just shooting off at the keyboard. Learn something, you're obviously smart. Efficiency, simplicity, smart design and COTS (commercial off-the-shelf) hardware are how we will get up there safely and successfully. <br /><br />If you want LCD TVs and gourmet food, what does it matter the craft that brought it? Chances are it's going to be a one-way tug like Progress. Focus on what to do in space, not the ride there. <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>
>if NASA will think useful some "aerobraking" will use it<br /> /> opinion is that costly modules must remain in earth orbit to be reused many times, instead of launch (and burn) all modules<br /> />starting from this (efficient) principle, NASA may use the technology they think better and reliable <br /><br />Hence their choice of a capsule using already flown aerodynamics. What you are actually advocating is to create a reusable, sustainable in-space transport architecture. Campaign for that, not the ride up. <br /><br />If this is your concern, I agree with you. Refuelable "tug" craft make a lot of sense, especially if we can use lunar/etc oxygen. The EDS that is part of Constellation/CEV could very well be reusable if we start advocating now. <br /><br />As far as the ride goes, it looks like the competition is Soyuz, Shenzhou and whatever t/space cooks up as the manned orbital systems available in the next 5-10 years. Maybe something via Kliper. I'm really nervous about CEV as NASA launcher because of the recent memos - NASA maybe about to be gutted. This might force them (if agency is still around) to buy seats commercially. Of the likely offerings, they are capsules and blunt side-entry "irons" - something between a lifting body and Corona capsule. None are delta-winged spaceplanes, not even X-30-type wedges. The only commercially available manned spacecraft right now, Soyuz, uses three modules, one of which is a bell-shaped Decent Module. You can't buy seats on Shuttle, but you can on this existing craft. Spaceplanes may well be a technologic dead-end, just cause it's sexy doesn't mean it's successful.<br /><br />Josh <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>
Actually the Apollo reentry was at approx. 11km/s compared to a standard LEO reentry of about 7.5km/s. Nevertheless this works out to be over twice the kinetic energy to be absorbed as heat in the atmosphere with correspondingly higher loads on the heat shield.
<br />"...on 'spaceplanes' that never flew..."<br /><br />all industries and research centers build dozens prototipes<br /><br /><br />"...demonstrated an in-ability..."<br /><br />NASA has ALREADY demonstated its ability... with winged and unwinged spacecrafts<br /><br /><br />"...explore the moon and mars..."<br /><br />moon is ten steps up the plane, mars is 10 steps up moon... if to-day's NASA can't build a simple plane can't go to moon or mars<br /><br /><br />"...improve upon shuttle..."<br /><br />Shuttle fails because it is NOT a true spaceplane, it is a (dangerous) "ROCKET with wings" that, only on reentry, become a spaceplane, a true spaceplane will NOT fails the target<br /><br /><br />"...unprotected from micrometeors..."<br /><br />very important but easy to resolve, not a good reason to don't make it, micrometeors can break both the capsule shield and its "protection"<br /><br /><br />
"...producing fuel locally..."<br /><br />of course, no, refueling will be on earth orbit<br /><br /><br />"...something you don't want to try with a liftingbody/spaceplane...."<br /><br />the spaceplane DON'T GO to moon so, don't need to reentry directly from moon (as I explain in my previous posts)<br /><br /><br />"...Efficiency is exactly what any space transport system needs..."<br /><br />sorry, but, I think this is a malicious interpretation of my words to denigrate my opinion and my critics about your loved "cone"<br /><br />of course, "efficiency" is VERY VERY VERY IMPORTANT in space transport but the "efficiency" can't be MANIACAL<br /><br />we CAN'T put six people and hardware in a "cone" because it is "efficient"<br /><br />we CAN'T destroy great part (95%!) of mission modules because it is "efficient"<br /><br />we CAN'T make 20 "high efficiency" but RISKY missions instead of 10 "inefficient" but SAFE<br /><br />we CAN'T stop for 10-15 years the progress of suborbital and space technology (that only NASA can lead, NOT private!) to build an "efficient" Pepsi-can to remake the "moon-movie"<br /><br />we CAN'T give to astronauts only "one-shot" (very risky) devices because too much redundancy is not "efficient"<br /><br /><br />there is a GOOD efficiency (engines, tanks, launch pads, computers, thermal shields, etc. must be as much as possible efficient!) and a BAD and DANGEROUS efficiency<br /><br />a "true progress" is ALSO have in space (and on the moon) a comfortable ambient that resemble our planet (not very expensive but "efficient" "astronauts' tanks"), expecially if (as I think must be) moon mission will be of months NOT days (with so costly missions explore only a few days per mission is a GIANT waste of money and DON'T WORTH the risk!)<br /><br />
"...Spaceplanes may well be a technologic dead-end..."<br /><br /><br />NASA or NOT... the near future of orbital space will be MUCH MORE "spaceplaned" than "capsulized"<br /><br />NASA choice of "capsule" may delay this (rational) scenario, but, when other national space agencies and private companies will improve the spaceplane technology and build low cost and reliable model, NASA will remain ALONE with its old (but "mass-per-space-efficient"!) "toy-cone" and, probably, will decide to send it to space museum and buy some winged-craft's tickets for space from CCSA (an humiliation that NASA have already had depending from russian Soyuz to launch its astronauts...)<br /><br /><br />
The first U-boats were built to look like boats, but due to this their performance suffered when submerged. Eventually U-boats were re-designed with the familiar blunt nose and round body to maximize their performance underwater, while sacrificing their performance on the surface. <br /><br />Just because a plane is the best way to get around inside the atmosphere, doesn't mean it's the best way to be entering and exiting it, in exactly the same way that a boat doesn't work as well underwater as it does on the surface. <br /><br />There is plenty of research going on that may lead to a highly efficient spaceplane, the military is pouring money into the HyFly program to develop a hypersonic cruise missile, and NASA is working on test facilities to research hypersonic flight up to mach 20. But since the test facilities to do basic research haven't even been built yet, the actual engines and craft that will do the job are years from even the drawing table. If we're lucky, military folk will be so enamoured of their hypersonic, air-breathing cruise missiles, they'll pay for the development of air-breathing ICBMs. From there a SSTO space-plane is only a hop, skip and a jump.
I know it was just an analogy, but I had to make one observation:<br /><br />Because of their limitations in battery power under water, early subs were really surface ships that could sink in a controlled way and move slowly. Their design was actually optimized more for the surface role because of their power limitations.<br /><br />When underwater propulsion improved, and speeds were increased, the design trade space moved more to the underwater side. From this of course arose the now famous albacore form we all know and love.<br /><br />This in no way detracts from what you said - I just have a thing for sub history, and babble a lot when tired...<br /><br />Wayne <div class="Discussion_UserSignature"> <p>"1) Give no quarter; 2) Take no prisoners; 3) Sink everything." Admiral Jackie Fisher</p> </div>
>"...producing fuel locally..."<br /> />of course, no, refueling will be on earth orbit <br /><br />The service module tanks are empty once in lunar orbit, which is where they need to be refueled to have the delta-V to decelerate into low Earth orbit. This is why direct entry or blunt capsule shapes make sense, you don't need fuel to reenter, you just dive in. Alternatively, the system could rendevouz with a LEO station via aerocapture, again something both fuel efficient and requiring conic or biconic reentry forms, not delta wings. It's physics and supply, simple. <br /><br />True progress is whatever creates sustainable societies off-Earth. I said it earlier, the shape of the vehicle that gets us into space (as individuals, not Heroes of the State) the shape is unimportant. Getting out there and doing is important.<br /><br />Would you refuse a ticket on a capsule-based spaceflight?<br /><br />Josh <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>
Correct, the SM was quite impressive.<br /><br />Only very tangentially realted to this: the service module engine was even capable of doing an "in front of the moon" abort until fairly late in the trip. It had quite a bit of fuel and delta V capability.<br /><br />Wayne <div class="Discussion_UserSignature"> <p>"1) Give no quarter; 2) Take no prisoners; 3) Sink everything." Admiral Jackie Fisher</p> </div>
I don't think people are suggesting that the crew needs to remain in the capsule for an extended period of time.<br /><br />The capsule is only for surface to LEO and re-entry from LEO or higher orbit or from the moon.<br /><br />The optimal situation is to have the minimum mass re-enter. That's less stuff that needs to be re-boosted.
>Not exactly, I believe the SM propulsion module is used to burn out of Low Lunar Orbit (LLO<br /><br />empty compared to 'has enough fuel for LEO insertion'. i know that apollo sm provided TEI burn, don't have the numbers handy, but it would be vastly more fuel than aerocapture or direct decent.<br /><br />i posed the question t gaetano, but would anyone refuse any flight into space based on (insert hated craft here)??<br /><br />josh on the palmpilot <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>
"...There is plenty of research going on that may lead to a highly efficient spaceplane..."<br /><br /><br />you talk about spaceplane like a "science-fiction" invention (or an UFO)<br /><br />but (a bad version) ALREADY EXIST and fly: Shuttle<br /><br />the next spaceplane will be SIMPLY a BETTER Shuttle... without cargo-bay, minimum wings to land, no giant bomb-like tank and rockets, light materials and better thermal shields using latest technology<br /><br />NASA can make it in 5 years, Russia-ESA can make it in 5-10 years, CCSA (I think) WILL MAKE it in 10-15...<br /><br />despite you love it or not<br /><br />and... when it will fly... capsule will appears as it really is... a "toy" <font color="yellow">(and the last NASA mistake, after which NASA will be sold to Lenovo...)</font><br /><br />
"...The service module tanks are empty..."<br /><br />of course, the lunar-system must have the fuel for the entire mission when leaving earth orbit<br /><br />it is less efficient than Apollo-like mission but allows to reuse 10-up times the (very expensive) earth/moon/earth orbit ferry<br /><br />it is only fuel!<br /><br />it costs, but not so much as burn the entire lunar-system at each mission<br /><br />the saving of the FIRST reuse of the earth-lunar-earth ferry will be sufficient to buy and send in space fuel for five missions!<br /><br /> <br />"...Would you refuse a ticket on a capsule-based spaceflight?..."<br /><br />no... but the problem with capsule is that will be very few tickets to buy...<br /><br /><br />
"...remain in the capsule for an extended period of time..."<br /><br />I don't suggest to send in space a cruise ship!<br /><br />crew spaceplane may be like capsule but with a little different shape, aerodynamic body and two (little) wings to glide and soft (safer) landing<br /><br />the "mass" of crew spaceplane will be NOT 200-300-500% than a capsule but only around +30%<br /><br />may be less efficient than capsule, but has MANY advantages (as explained in previous posts)<br /><br />also, the working little spaceplane may have an "evolution"... from that experience many scientific and commercial vehicles will born<br /><br />from capsule experience NOTHING useful can born (only another capsule...)<br /><br /><br />
Only if the cost of refurbishing and refuelling the service module for reuse is less expensive that sending up a new one. Take a look at satellite repair, it has not so far been worth the money to refurbish and refuel satellites rather that sending up new ones.<br /><br />If you want to break the SM into LEO using rockets then you are probably talking about an extra couple of HLLV launches for each mission, at $1-2B a pop that’s one expensive SM you have there.<br />
<br />"...Take a look at satellite repair..."<br /><br />90% of satellites are very expensive<br /><br />repair them may be a giant money saving... but it is IMPOSSIBLE because there is not a service-car to do it<br /><br />the only space-service-car was Shuttle (like in Hubble repair) but Shuttle is grounded (and probably will never fly again)<br /><br />also, great part of commercial satellites are in geostationary orbit where Shuttle can't go<br /><br />satellite repair is a technical problem not an economical problem<br /><br />also, manned module will cost ten times than a satellite, so, refueling it will be a GIANT saving!<br /><br /><br />"...an extra couple of HLLV launches..."<br /><br />not so much, the planned lunar mission will need one ($400 million) SDLV to launch the earth-moon rocket and LEM-2<br /><br />the extra fuel (or extra rocket) may need half-SDLV payload (or less, with only another "stick" launch with extra fuel tank instead of CEV-SM)<br /><br />
<br />It is an economic problem, because nobody wants to repair their old satellites. There is no market for it...<br /><br />Satellites rarely fail and when they do the thing is probably obsolete anyway.