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Space Forum / Shuttle / March 2004CEV development cost rumbles
The 23Feb04 issue of Aviation Week reports that NASA is telling Congress that the Crew Exploration Vehicle (CEV), the space agencies latest and greatest orbiter replacement, will cost $15B to develop. Earlier NASA estimated that the Orbital SpacePlane (OSP), last year's super-duper orbiter replacement, would cost $10-13B (todays bucks). NASA keeps turning the crank and coming up with the same numbers. The development cost of the original orbiter was about $14B in today's money. None of this is surprising because, even though the orbiter was designed over 30 years ago, spacecraft technology hasn't changed much at all. The CEV, the OSP and the orbiter all use the same technology, namely, Apollo heritage technology. So when measured in constant dollars, the development cost for these vehicles will be about the same, despite significant differences in size and weight. Why? Because the cost of airframe structure is a relatively small part of the development cost. It's the complex systems (avionics, environmental control/life support, guidance, navigation, communication, flight computer/software, hydraulics, thermal control, RCS, APS, etc.) that determine the development cost and these systems are essentially the same regardless of the size of the vehicle. There have been no major breakthroughs in these complex systems during the last 30 years that will cause a significant decrease in theirdevelopment cost. Later Ray Schmitt >There have been >no major breakthroughs in these complex systems during the last 30 years >that will cause a significant decrease in theirdevelopment cost. Nor is it written anywhere that there ever will be such a breakthrough. D.  SignatureTouch-twice life. Eat. Drink. Laugh. > that the Crew Exploration Vehicle (CEV), the space agencies latest and > greatest orbiter replacement, will cost $15B to develop. I know that this would not be a popular suggestion, but how much would it cost to build new shuttles nearly identical to the existing ones ? How much more would it cost to add in all the improvements NASA has wished it could do (electric APUs etc) ? How much more would it cost to replace SRBs with liquid fueled flyback boosters ? (or whatever technology is deemed best to replace the SRBs) ? How much more would it cost to rework the engine area to make it simple, fast and cheap to remove/replace engines ? Would there be any significant advantage in having the SSMEs attached to the ET instead of actual shuttle ? (either as a capsule with its parachutes for re-usability, or using disposable engines). Instead of dreaming of a totally radically new vehicle NASA has no idea how to build, wouldn't it be more realistic to just build new and improved shuttles ? If you start with the base model and then add each new improvement, at one point, you will reach the "sorry, we can't afford this" level, at which point your new shuttle's designed is finalised with only the improvements you can afford ? Yes, I know all the tooling for shuttle is gone. But the tooling for CEV doesn't exist either. However, there are a lot of things about Shuttle which are still manufactured (tiles, engines and I am sure countless other components that are regularly replaced). >> that the Crew Exploration Vehicle (CEV), the space agencies latest >> and greatest orbiter replacement, will cost $15B to develop. > > I know that this would not be a popular suggestion, but how much would > it cost to build new shuttles nearly identical to the existing ones ? About $2 billion a copy, plus the fixed costs of getting the line going again. > How much more would it cost to add in all the improvements NASA has > wished it could do (electric APUs etc) ? Electric APU alone is in the $550 million range, IIRC. > How much more would it cost to replace SRBs with liquid fueled flyback > boosters ? (or whatever technology is deemed best to replace the SRBs) > ? In the range of $3-5 billion. > How much more would it cost to rework the engine area to make it > simple, fast and cheap to remove/replace engines ? No idea. > Would there be any significant advantage in having the SSMEs attached > to the ET instead of actual shuttle ? (either as a capsule with its > parachutes for re-usability, or using disposable engines). No. SSMEs are expensive. Throwing them away would be ridiculously expensive. Developing a recovery capsule would take years, probably hundreds of millions of dollars, and would add weight to the stack. RS-68s would be cheaper but the Isp is significantly less, so performance would suffer. Moving the SSMEs to the bottom of the ET would mean reworking the MLPs, TSMs and the flame trenches on the pads. It would also significantly change the thermal/acoustic environment at the base of the SRBs. SignatureJRF Reply-to address spam-proofed - to reply by E-mail, check "Organization" (I am not assimilated) and think one step ahead of IBM. > How much more would it cost to replace SRBs with liquid fueled flyback > boosters ? (or whatever technology is deemed best to replace the SRBs) ? NASA replowed this ground in 2001-02 as part of the so-called Space Launch Initiative (SLI) effort. The SLI folks spent time and money on studying a shuttle replacement consisting of a fully-reusable two-stage vehicle with a large flyback booster. The development cost was an estimated $30-35B (in today's bucks). Sean O'Keefe had several independent studies made to keep the SLI folks honest and these came up with essentially the same numbers. Not surprising. When I worked on the original shuttle Phase A effort (1969-70) at McDonnell Douglas, this two-stage monster was our baseline for awhile and our estimated development cost was $37B (in today's money). Again, not surprising that these numbers agree despite over 30 years of separation, because the technology remains the same. > How much more would it cost to rework the engine area to make it simple, fast > and cheap to remove/replace engines ? Don't know. > Would there be any significant advantage in having the SSMEs attached to the > ET instead of actual shuttle ? (either as a capsule with its parachutes for > re-usability, or using disposable engines). Each SSME costs about $50M to manufacture (current dollars). NASA spends about $200M per year (current dollars) to maintain the SSME inventory. The shuttle flies, on average, 5.5 times per year. So 15-18 SSMEs are flown each year. So NASA is paying about $11M per SSME flown. If you can build an SSME substitute (e.g. Rocketdyne's RS-68 that powers the Delta IV CBC) for less than $11M per copy, then you might consider strapping a few of these engines to the bottom of the ET and dumping them into the Indian Ocean along with that tank. BTW, NASA studied a similar configuration in the late 1970s when it became evident that the shuttle could not meet the USAF requirement to place 32,000 pounds payloads launched out of VAFB into a polar reference orbit (100 nm altitude circular orbit at 90 deg inclination). NASA and Martin figured out how to beef up the structure in the bottom of the ET to attach liquid or solid rocket boosters to give the shuttle more lift for the launches to polar orbit. > Instead of dreaming of a totally radically new vehicle NASA has no idea how to > build, wouldn't it be more realistic to just build new and improved shuttles ? > If you start with the base model and then add each new improvement, at one > point, you will reach the "sorry, we can't afford this" level, at which point > your new shuttle's designed is finalised with only the improvements you can > afford ? What improvements? As I mentioned at the start of this thread, there have been no "improvements" made in spacecraft and launch vehicle technology during the last 30 years that will produce large reductions in either development cost or operations costs. Why? First, because the technology is difficult ( especially in the high temperature materials area, where I spent about 15 years of my aerospace career) and we have been in a region of diminishing returns since the early 1970s. And, second, there just hasn't been much R&D money spent during the last 30 years on this technology. For example, there has been only one new high thrust engine developed in the last 20 years, namely, the RS-68, which, BTW, is a legacy engine that relies heavily on technology developed in the late 1960s for the excellent Rocketdyne J-2S engine, which, in turn, was a simplified version of the venerable J-2S engine that powered the 2nd and 3rd stages of von Braun's Saturn V ELV. > Yes, I know all the tooling for shuttle is gone. But the tooling for CEV > doesn't exist either. However, there are a lot of things about Shuttle which > are still manufactured (tiles, engines and I am sure countless other > components that are regularly replaced). technology > during the last 30 years that will produce large reductions in either > development cost or operations costs. Why? First, because the technology is [quoted text clipped - 8 lines] > venerable J-2S engine that powered the 2nd and 3rd stages of von Braun's > Saturn V ELV. Oops, that should be "J-2" engines, not J-2S, on the Saturn V. > What improvements? As I mentioned at the start of this thread, there have > been no "improvements" made in spacecraft and launch vehicle technology > during the last 30 years that will produce large reductions in either > development cost or operations costs. My opinion is still do at least Orbiter Mark II. Start with a design for which we know what's good, bad, and ugly. Or 30 years from now we'll be saying what a shame...the Saturn V never really got refined, nor did the shuttle orbiters. I know about the upgrades program, and how different the vehicles are now than when they were built, but still, to refine the design without the restrictions of well, not being able to build one *new* might be a good idea. For god's sake, Columbia was a freak accident, now all of a sudden the shuttle is a deathtrap we need to sweep under the rug ASAP? Bleh. SignatureThis is a siggy | To E-mail, do note | Just because something It's properly formatted | who you mean to reply-to | is possible, doesn't No person, none, care | and it will reach me | mean it can happen > My opinion is still do at least Orbiter Mark II. Start with a design for > which we know what's good, bad, and ugly. Or 30 years from now we'll be [quoted text clipped - 5 lines] > all of a sudden the shuttle is a deathtrap we need to sweep under the rug > ASAP? Bleh. A fleet of OV-200s would be a fine idea. The price isn't bad, and the vehicle would be based on a reasonably well-understood design. Unfortunately, it'll never get up due to the lack of a launch escape system. I strongly agree with your point about the perception of shuttle going from a boring, routine, reliable workhorse to a deathtrap in an instant. Yes, we did mismanage signs that something bad may be about to happen. We're all much wiser now and we are adopting a much more conservative approach to potential flight safety issues. It's very unfortunate that it took the loss of Columbia and her crew for us to come to this point. It's not so much the space shuttle system that's the real deathtrap, it's the way we have managed it in the past. Had we managed any other vehicle the way we managed the space shuttle, we would have suffered a major failure, although a LES may have prevented loss of life. --Chris >A fleet of OV-200s would be a fine idea. The price isn't bad, and the >vehicle would be based on a reasonably well-understood design. >Unfortunately, it'll never get up due to the lack of a launch escape >system. Oh? Let me borrow the time machine you used to see the designs for the OV-200 series, I need to check out some future stock prices. D. SignatureTouch-twice life. Eat. Drink. Laugh. >>A fleet of OV-200s would be a fine idea. The price isn't bad, and the >>vehicle would be based on a reasonably well-understood design. [quoted text clipped - 3 lines] > Oh? Let me borrow the time machine you used to see the designs for > the OV-200 series, I need to check out some future stock prices. Isn't OV-200 generally interpreted as 'shape, size, plugs, stay - but make the rest better'? - which'd imply that the designs, at least as regards LES and other such macro-changes, are pretty firm. On the other hand... if you had sufficient silly money, it's not implausible to retrofit an LES of the form of "two damn great solid rockets by the wing roots"... which, if memory serves, was where it got to in the design stage before falling off the board. Signature-Andrew Gray shimgray@bigfoot.com > Isn't OV-200 generally interpreted as 'shape, size, plugs, stay - but > make the rest better'? - which'd imply that the designs, at least as > regards LES and other such macro-changes, are pretty firm. That's what I was thinking of when I posted, a new-build airframe of the same design as the existing orbiters, but with upgraded systems (eg electric APUs, perhaps non-toxic OMS/RCS, etc). > On the other hand... if you had sufficient silly money, it's not > implausible to retrofit an LES of the form of "two damn great solid > rockets by the wing roots"... which, if memory serves, was where it got > to in the design stage before falling off the board. Doing that would add weight to the orbiter's structure, but that could be comphensated for if the abort SRMs were fired and jettisoned shortly after SRB separation (at which point they would be unnecessary, and could probably be retrieved for refurbishment). --Chris >> Isn't OV-200 generally interpreted as 'shape, size, plugs, stay - but >> make the rest better'? - which'd imply that the designs, at least as [quoted text clipped - 3 lines] > same design as the existing orbiters, but with upgraded systems (eg > electric APUs, perhaps non-toxic OMS/RCS, etc). And the various incremental upgrades that have been installed since 1977, as well. Essentially more a case of "bring the standards up to [a new] spec, then re-open the line" rather than "build a new vehicle" - probably about as expensive to start production, all told, but probably also less risky (in that it's a design with familiar qualities) in project if not flight terms. >> On the other hand... if you had sufficient silly money, it's not >> implausible to retrofit an LES of the form of "two damn great solid [quoted text clipped - 5 lines] > SRB separation (at which point they would be unnecessary, and could > probably be retrieved for refurbishment). I vaguely recall Jenkins suggested they were likely to be about payload-neutral... but they'd add a new failure mode and Not Come Cheap. Signature-Andrew Gray shimgray@bigfoot.com > In article <c2488f$1nvmt5$1@ID-78250.news.uni-berlin.de>, Chris > Bennetts wrote: [quoted text clipped - 12 lines] > payload-neutral... but they'd add a new failure mode and Not Come > Cheap. They also provide meaningful abort assistance during only about 30 seconds of ascent. Plus they were going to be expensive to develop ($300 million in 1972 dollars, or over $1 billion today). SignatureJRF Reply-to address spam-proofed - to reply by E-mail, check "Organization" (I am not assimilated) and think one step ahead of IBM. >>>A fleet of OV-200s would be a fine idea. The price isn't bad, and the >>>vehicle would be based on a reasonably well-understood design. [quoted text clipped - 7 lines] >make the rest better'? - which'd imply that the designs, at least as >regards LES and other such macro-changes, are pretty firm. The concept of OV-200 has been interpreted in a wide variety of way, from simply plug-compatible to plug- and moldline- compatible and beyond. D. SignatureTouch-twice life. Eat. Drink. Laugh. > A fleet of OV-200s would be a fine idea. The price isn't bad, and the > vehicle would be based on a reasonably well-understood design. > Unfortunately, it'll never get up due to the lack of a launch escape > system. Perhaps, but without the original USAF payload size and mass requirements Shuttle II could scale back the payload bay and make use of the mass savings to implement an escape system. Signaturebp Proud Member of the Human O-Ring Society Since 2003 (replace ".dot." in email address with ".") > A fleet of OV-200s would be a fine idea. The price isn't bad, and the > vehicle would be based on a reasonably well-understood design. > Unfortunately, it'll never get up due to the lack of a launch escape > system. I recall some discussion in this group about the crew cabin's toughness. Why not just make the *entire* structure the crew escape...something. *Not* an ejectable "pod" though. What I'm thinking is toughen up the pressure vessel, let the vehicle break up around it, and keep the crew cabin intact. Not necessarily intact, as in "self contained vehicle", but rather simply a box with people in it that can take a little punishment. The next bit in my plan is tricky, getting rid of that box when you're at altitudes that would allow "bail-out". Ideally, it should be able to just go "poof" and the crew be out in the open, just like that. Perhaps big blowout panels? Say the aft bulkhead. A CG that will ensure that the cabin stabilizes nose down. Astros lean their seats all the way back and just unbuckle, opening their chutes when they're clear of the "wreck". I know there's some serious issues and problems with this approach, but does it sound like a non-starter? And note that this is strictly something to be incorporated into the OV-200 series. SignatureThis is a siggy | To E-mail, do note | Just because something It's properly formatted | who you mean to reply-to | is possible, doesn't No person, none, care | and it will reach me | mean it can happen >> A fleet of OV-200s would be a fine idea. The price isn't bad, and the >> vehicle would be based on a reasonably well-understood design. [quoted text clipped - 6 lines] > thinking is toughen up the pressure vessel, let the vehicle break up > around it, and keep the crew cabin intact. This is similar to what Gen. Deal proposed in CAIB appendix D: a layer of ablative in between the crew cabin and the forward fuselage shell. The concept has some challenges. One, it makes the orbiter even more nose-heavy than it already is. This is bad because the orbiter CG has to be in a fairly small "box" in order for the flight control system to work (this is a problem with many shuttle escape-system concepts, BTW). Two, there's lots of wiring running in the gap between the fuselage and the cabin, and adding ablative would make that wiring much less accessible for inspection/repair. Aging Kapton wiring is a major safety concern for the fleet now. So this is not an unmitigated win for safety. Of course, you're talking about an OV-200 design while Deal was talking about the existing orbiters. SignatureJRF Reply-to address spam-proofed - to reply by E-mail, check "Organization" (I am not assimilated) and think one step ahead of IBM. > This is similar to what Gen. Deal proposed in CAIB appendix D: a layer of > ablative in between the crew cabin and the forward fuselage shell. The [quoted text clipped - 9 lines] > Of course, you're talking about an OV-200 design while Deal was talking > about the existing orbiters. Would you need an ablative in a Columbia type situation? I imagine other improvements would mitagate such a repitition anyway. My major concern with this approach is how to get the astros out in a semi-sane manner, i.e. I can't imagine them crawling around in a falling, probably damaged cabin. I've got visions of the entire aft bulkhead just going bye bye, but how do you ensure that in a situation of the type we're talking about here? I'm not smart enough to figure that one out, and I'm sure you're still going to be wanting to beef up the suits to handle any debris in the area. But this is exactly the reason I believe a 200 series is almost necessary. There are definately things which could be fixed in a new build that can't be patched into an existing vehicle. SignatureThis is a siggy | To E-mail, do note | Just because something It's properly formatted | who you mean to reply-to | is possible, doesn't No person, none, care | and it will reach me | mean it can happen >My opinion is still do at least Orbiter Mark II. Start with a design for >which we know what's good, bad, and ugly. Or 30 years from now we'll be >saying what a shame...the Saturn V never really got refined, nor did the >shuttle orbiters. <nods> There's been rumbles of that now and again in these NG's, but folks rarely want to address it directly. There is a gospel/dogma that Apollo was near perfect, and thus all capsules are near perfect, and that since the Shuttle is flawed, all descendants thereof are irredeemably flawed as well. D. SignatureTouch-twice life. Eat. Drink. Laugh. > >My opinion is still do at least Orbiter Mark II. Start with a design for > >which we know what's good, bad, and ugly. Or 30 years from now we'll be [quoted text clipped - 7 lines] > capsules are near perfect, and that since the Shuttle is flawed, all > descendants thereof are irredeemably flawed as well. Actually, Derek, many of those who have been shuttle supporters for a long time have been slowly picking up on what the capsule people have been saying: winged designs are hard, so lets put off doing another winged design for a while, pick an easy design and see if we can get the flight rate up. Have the research centers continue to work on TPS designs, let DOD do a scram jet, and then revisit winged vessels when we have better materials and/or design. Seperately, many of us who have been reusable space craft supporters for a long time have been slowly picking up on what the expendable people have been saying: reusable designs require high flight rates to avoid being expensive (and worse, expensive up front), so lets concentrate on making reliable expendables that can get the flight rate up on a pay-as-you go basis, and then use those reliable components in steps to getting back to reusable craft. The shuttle is sexy, major impressive, and has done things that Apollo designers would give right arms for. But it requires heroic efforts to be usable. Apollo required heroic efforts. But the route to CATS requires something where heroic is too much. The fabled "airliner flight-line turnaround" is part of the discussion, and EELVs are a step closer; DC-X was a step closer; Falcon-V and Spaceship One are steps closer. Maybe Kliper is a step closer. 200-series orbiters are possible. But they would be only an incremental improvement in design, and Big Bucks items as much as Buck Rogers. Capsules designs on make significant advances over Apollo for better bang for the Big Bucks. /dps P.S. For Ray, here's a question: why would a capsule version of OSP or CEV require as many lines of code as a shuttle? The GNC should be a lot simpler, especially on a LEO-version (start with a modest computer for CEV-L, replace the Pentium with a Pentium Pro for CEV-S (S=Selene for the moon shots), and go with an Itanium for CEV-M (Mars); processor names chosen for familiar analogy rather than as an actual design point). In addition, many of those lines of code should already exist (GEO transfer stage guidance, for instance). ELCSS should also be closer to "off the shelf" now that we have experience with Soyuz, Apollo, and Shuttle designs; the ISS designs are also useful input, but would be overkill on a 4-day flight. Space suit designs might also have given us engineering data that would help with a compact modular unit (here's an opportunity for a reusable component in an expendable airframe). Modelling a capsule's aerodynamics and heat transfer should be simpler than a winged design, thus saving CFD and wind tunnel costs. So many systems should be easier to design and/or manufacture on a capsule CEV that I would expect to see big savings from adding up all the smaller savings. Do we lose all that in system integration costs? Would they really be as bad or worse than the SI for the shuttle? Tnx /dps > been saying: winged designs are hard, so lets put off doing another > winged design for a while, pick an easy design and see if we can get > the flight rate up. Are the X33 style of self lifting vehicles harder or simpler than real wing such as Shuttle ? The shuttle is a known entity. > Have the research centers continue to work on TPS > designs, let DOD do a scram jet, and then revisit winged vessels when > we have better materials and/or design. It is one thing to have scientists design a new TPS in a lab. You need a shuttle to really test it. How many shuttle flights did it take before NASA had acquired sufficient knowledge of the original TPS system to make changes to it ? If they develop a new TPS system, why not retrofit it on the shuttles (whether 100 or 200 series) ? > to avoid being expensive (and worse, expensive up front), so lets > concentrate on making reliable expendables that can get the flight > rate up on a pay-as-you go basis, When you consider the "man rated" issues, would expandables really be cheaper once you add all the redundancy and robustness that is required ? Expandables got popular when the russians were able to offer a seat for 20 million bucks to tourists. And they got popular whenever the shuttle was delayed (and now grounded) while Soyuz/Progress always launch on time. But if you were to transpose Soyuz to NASA, wouldn't NASA make significant modifications to "man rate" it, and then add a billion flight rules to ensure safety which would make it just as "reliable" as Shuttle ? > 200-series orbiters are possible. But they would be only an > incremental improvement in design, I think that a new and improved shuttle could be far more than "incremental". There have not only be fairly substantial changes to the shuttle since it first flew (TPS comes to mind), but also, experience has also shown many of the design problems of the 100 series (for instance, access to engines, something which original designers didn't think would be needed between flights). If the current shuttle has a series of kinks, which, when put together, require much longer stay in OPF thus increasing costs significantly, then fixing those kinks could significantly lower maintenance costs (for instance, electric APUs that don't require the purging of dangerous fuel lines/tanks). And for OMS/thrusters, perhaps they could design the plumbing such that their purging could be greatly facilitated. A lot has been learned since the original shuttles, and I suspect that if you were to put all this experience together, you could build a 200 series shuttle that would have sighificant advantages over current ones without having to totally re-invent the wheel. > The GNC should be > a lot simpler, especially on a LEO-version (start with a modest > computer for CEV-L, replace the Pentium with a Pentium Pro for CEV-S > (S=Selene for the moon shots), and go with an Itanium for CEV-M > (Mars); Hardware is irrelevant. A 386 is probably more than enough. GNC is not the only thing that needs source code. You need ECLSS, C&C, remote controllability from ground, all the telemetry, caution alarm system, communications. You also need al the interfaces to the actual launch vehicle. > experience with Soyuz, Apollo, and Shuttle designs; the ISS designs > are also useful input, but would be overkill on a 4-day flight. Last I heard, going to the moon was 3 days each way. Right ? So that would be 6 days + contigency planning. How many people are you carrying to the moon ? 3 ? 6 ? Shuttle's ECLSS is probably better sized than Apollo. Also, remember that if you're going to be using the CEV as a shuttle between earth and moon base alpha, you'll also want each CEV to bring lots of supplies to the moon base. If you're sending 4 people to stay on the moon for a month, you'll need to carry a couple month's worth of supplies (again, you need contigency). Going to mars, the CEV is useless. ISS is useful. For building Moon base , CEV is useless, ISS is usefull (in terms of already built systems). > Modelling a capsule's aerodynamics and heat transfer should be simpler > than a winged design, thus saving CFD and wind tunnel costs. How significant would those costs be ? Doesn'.t NASA already have plenty of empirical experience with the shuttle's wing ? (including its behaviour during columbia final's re-entry). > > Have the research centers continue to work on TPS > > designs, let DOD do a scram jet, and then revisit winged vessels when [quoted text clipped - 7 lines] > If they develop a new TPS system, why not retrofit it on the shuttles (whether > 100 or 200 series) ? Cost. To keep costs down, the TPS on the shuttle isn't generally stripped down to nothing and reapplied. Instead, pieces are replaced only when necessary. > > to avoid being expensive (and worse, expensive up front), so lets > > concentrate on making reliable expendables that can get the flight > > rate up on a pay-as-you go basis, > > When you consider the "man rated" issues, would expandables really be cheaper > once you add all the redundancy and robustness that is required ? Shuttle isn't "man rated". If NASA bends the rules (waivers) for the shuttle, why can't they be bent for its replacement? > Expandables got popular when the russians were able to offer a seat for 20 > million bucks to tourists. And they got popular whenever the shuttle was > delayed (and now grounded) while Soyuz/Progress always launch on time. Expendables didn't "get" popular. The only entity trying to reuse launch vehicles is NASA (and perhaps the carrier planes used by Pegasus), and they've had a very poor record of reducing costs by using a "reusable" vehicle. > But if you were to transpose Soyuz to NASA, wouldn't NASA make significant > modifications to "man rate" it, and then add a billion flight rules to ensure > safety which would make it just as "reliable" as Shuttle ? See above "man rating" comments. > > 200-series orbiters are possible. But they would be only an > > incremental improvement in design, [quoted text clipped - 4 lines] > the design problems of the 100 series (for instance, access to engines, > something which original designers didn't think would be needed between flights). Making the engines easier to pull and reinstall is fixing the symptom, not the problem. > If the current shuttle has a series of kinks, which, when put together, > require much longer stay in OPF thus increasing costs significantly, then > fixing those kinks could significantly lower maintenance costs (for instance, > electric APUs that don't require the purging of dangerous fuel lines/tanks). > And for OMS/thrusters, perhaps they could design the plumbing such that their > purging could be greatly facilitated. Fixing all of the "kinks" would cost billions. This isn't an exaggeration, considering the cost of some shuttle upgrades that have either been done, or have been canceled due to rising costs (e.g. electric APU's). > A lot has been learned since the original shuttles, and I suspect that if you > were to put all this experience together, you could build a 200 series shuttle > that would have sighificant advantages over current ones without having to > totally re-invent the wheel. First, it's stuck in LEO. This is true for a variety of reasons, not the least of which is the "dead weight" of the vehicle that you *don't* want to take out of LEO (wings, main engines, structure to hold it all together...). Second, it's simply not suited to exploration (ignoring the cost and weight issues). You really don't need a payload bay 15'x60' for manned missions to the moon and Mars. This huge bay was due to USAF requirements that no longer apply. Third, you don't need wings. They add complexity (moving parts), cost, mass, and etc. Unfortunately, they don't add much value either. For lunar and Mars missions, is there a *valid* requirement to land on a runway? Fourth, it's both a launch vehicle and a manned space vehicle. Why mix the two? Fifth... > Going to mars, the CEV is useless. ISS is useful. For building Moon base , CEV > is useless, ISS is usefull (in terms of already built systems). This is just false. ISS is useless for either lunar or Mars missions because it's in a very bad orbit (payload penalty paid by any vehicle that launches from KSC to ISS). CEV can be sent up into a much more optimal low earth orbit. CEV can return crews from the moon (let's see ISS do that). Jeff SignatureRemove "no" and "spam" from email address to reply. If it says "This is not spam!", it's surely a lie. >Expendables didn't "get" popular. The only entity trying to reuse >launch vehicles is NASA (and perhaps the carrier planes used by >Pegasus), and they've had a very poor record of reducing costs by >using a "reusable" vehicle. When a single instance can change your figure of merit significantly, that means your figure of merit is not a reliable guide. This is true whether analyzing safety statistics as in determining which approach is better than another. Or to put it simply; Once again, your argument can be reduced to 'Apollo was cool, Soyuz is cool, the Shuttle sucks. Therefore all capsules are cool and all winged vehicles suck.' D. SignatureTouch-twice life. Eat. Drink. Laugh. > >Expendables didn't "get" popular. The only entity trying to reuse > >launch vehicles is NASA (and perhaps the carrier planes used by [quoted text clipped - 5 lines] > whether analyzing safety statistics as in determining which approach > is better than another. That was my point. There is only one "reusable" vehicle, so how could expendables "get popular" when they've been doing the bulk of the lifting all along? > Or to put it simply; Once again, your argument can be reduced to > 'Apollo was cool, Soyuz is cool, the Shuttle sucks. Therefore all > capsules are cool and all winged vehicles suck.' That's not what I meant at all. I was replying to this: >> Expandables got popular when the russians were able to offer a seat for 20 >> million bucks to tourists. And they got popular whenever the shuttle was >> delayed (and now grounded) while Soyuz/Progress always launch on time. Expendables didn't "get popular" because the Russians started selling seats for $20 million. Besides the shuttle (and the aircraft which lifts Pegasus), expendables are the *only* way to get anything into orbit. Furthermore, you can't launch anything commercially, including people, on the world's only "reusable" vehicle, so it was *never* in commercial competition with those $20 million Soyuz seats. Commercial launches on the shuttle were banned after Challenger. This put a bad taste in the mouths of many who had to "go back" to expendables. This has nothing to do with the shuttle versus capsule debate. It does have something to say about the government monopoly on human space flight issue (which will hopefully change soon). Jeff SignatureRemove "no" and "spam" from email address to reply. If it says "This is not spam!", it's surely a lie. >> Or to put it simply; Once again, your argument can be reduced to >> 'Apollo was cool, Soyuz is cool, the Shuttle sucks. Therefore all >> capsules are cool and all winged vehicles suck.' > >That's not what I meant at all. It may not be what you *meant*, but it's what you *wrote*. And it's a pretty consistent viewpoint among many in this newsgroup. D. SignatureTouch-twice life. Eat. Drink. Laugh. [...] > It is one thing to have scientists design a new TPS in a lab. You need a > shuttle to really test it. How many shuttle flights did it take before NASA > had acquired sufficient knowledge of the original TPS system to make changes > to it ? Well, the Mercury TPS was tested with 2 Little Joe flights, and Apollo did the same thing. Shuttle TPS prototypes *might* have been on some sort of reentry vehicle in an equivalent test, I'm not up to speed on this. And the changes to the original TPS system, IIRC, were to use less expensive TPS on areas that turned out to be less exposed than expected. [...] > When you consider the "man rated" issues, would expandables really be cheaper > once you add all the redundancy and robustness that is required ? I'll defer to Kim Keller on this. > > 200-series orbiters are possible. But they would be only an > > incremental improvement in design, [quoted text clipped - 4 lines] > the design problems of the 100 series (for instance, access to engines, > something which original designers didn't think would be needed between flights). This sounds like a big enough change that it would no longer be considered the same airframe, and you're right where the winged OSP design teams were...a whole new vehicle. [...] > > The GNC should be > > a lot simpler, especially on a LEO-version (start with a modest [quoted text clipped - 3 lines] > > Hardware is irrelevant. A 386 is probably more than enough. Perhaps, but there are a lot more navigational computations and a lot more systems to monitor on a vessel doing 18-month flights with aa limited number of navigational buoys, so allowing more memory, faster processing, and more tasks may turn out to be an important feature by 2020. > GNC is not the > only thing that needs source code. You need ECLSS, C&C, remote controllability > from ground, all the telemetry, caution alarm system, communications. You also > need al the interfaces to the actual launch vehicle. Indeed, but again many of these things can leverage existing lines of code. > > experience with Soyuz, Apollo, and Shuttle designs; the ISS designs > > are also useful input, but would be overkill on a 4-day flight. > > Last I heard, going to the moon was 3 days each way. Right ? So that would be > 6 days + contigency planning. How many people are you carrying to the moon ? 3 > ? 6 ? Shuttle's ECLSS is probably better sized than Apollo. Okay, the 4-day figure came from LEO rendezvous ops. Whether doubling the number of units or doubling the size of one unit would be better for CEV-S missions is probably a Herb question. (Mr. S, not oregano) > Also, remember that if you're going to be using the CEV as a shuttle between > earth and moon base alpha, you'll also want each CEV to bring lots of supplies > to the moon base. If you're sending 4 people to stay on the moon for a month, > you'll need to carry a couple month's worth of supplies (again, you need contigency). Nah, send the supplies on an unmanned robot lander one launch before crew launch. Makes payloads fit launchers better, from the discussion around here. Besides, this seems like a step OT from the systems intgration question. If the supplies were in an SM-like cargo hold (a large SM ;-} ), that would still be a minimal impact on systems integration compared to the propulsion, RCS, life support, DVD player.... > Going to mars, the CEV is useless. ISS is useful. For building Moon base , CEV > is useless, ISS is usefull (in terms of already built systems). I assume you're still talking about design and system integration here, though some people have suggested trying to budge ISS out of orbit. And I agree with you, except to note that for Mars, the CEV will probably be a nice decoration once docked on the outbound flight and most of the inbound flight, but will get its real use on reentry, unless we get real good at refueling at Mars (see earlier discussions about orbital capture versus Apollo-like returns). > > Modelling a capsule's aerodynamics and heat transfer should be simpler > > than a winged design, thus saving CFD and wind tunnel costs. > > How significant would those costs be ? Doesn'.t NASA already have plenty of > empirical experience with the shuttle's wing ? (including its behaviour during > columbia final's re-entry). Ahhh, a Mary question (she did part of prior wing studies). And I appreciate the thoughtful post; this sort of give-and-take helps both sides come up with a better answer. /dps > [...] > > It is one thing to have scientists design a new TPS in a lab. You need a [quoted text clipped - 8 lines] > less expensive TPS on areas that turned out to be less exposed than > expected. Actually, the Little Joe I flights in Mercury were done to test the Launch Escape System (LES). Mercury's ablative heat shield was tested in the Big Joe flight on 8Sep1959. An Atlas 10-D missile sent a flight-weight Mercury spacecraft on a ballistic trajectory into the South Atlantic. The flight was about 80% successful (lower altitude and speed than planned), but was sufficient to qualify the Mercury TPS. Likewise, the Little Joe II flights in Apollo tested the Command Module LES. The CM TPS was first flight tested on the SA-201 (aka AS-201) sub-orbital flight (26Feb1966) using von Braun's Saturn-IB ELV. The CM was recovered and the ablative heatshield was in nearly pristine condition. Later Ray Schmitt >> Hardware is irrelevant. A 386 is probably more than enough. > >Perhaps, but there are a lot more navigational computations Easily handled by a single 386 with a proper OS and application software. >and a lot more systems to monitor on a vessel doing 18-month flights with aa >limited number of navigational buoys, I find it unlikely that a space vehicle for an 18 month flight will be more complex than a Trident submarine. Which submarine does all it's monitoring, all it's combat operations, all it's everything with the equivalent of about 6-8 386's. >so allowing more memory, faster processing, and more tasks may turn out >to be an important feature by 2020. I find that unlikely. Most people use a wintel box and it's increasing problems as their reference. Problem is, wintel systems have almost nothing to do with what a properly designed system with a proper OS and application software can do. D. SignatureTouch-twice life. Eat. Drink. Laugh. > P.S. For Ray, here's a question: why would a capsule version of OSP > or CEV require as many lines of code as a shuttle? The GNC should be [quoted text clipped - 23 lines] > > /dps You would think so. However, there're numerous studies going back to the days of the RLV Subpanel of the NASA/DOD Aeronautics and Astronautics Coordinating Board (1965) and the "Integral Launch and Reentry Vehicle" (ILRV, 1968) work that preceeded the shuttle Phase A effort (1969-70) indicating that the mode of reentry (capsule/parachute, lifting bodies/runway, or shuttle orbiters/runway) is not a strong driver of development cost. NASA spent about $20B (current dollars) to develop and manufacture five orbiters. Of this, $14B was spent on engineering development and for Enterprise, Columbia and Challenger. About $2B was spent for each of the last three orbiters, Discovery, Atlantis and Endeavour. For Apollo, the CSM cost was $22B (current dollars) for engineering development and for 12 Block I vehicles, 23 Block IIs and 20 boilplate units. When I worked on the DC-X/XA program at McDonnell Douglas in the early 1990s, we made a lot of PR noise about semi-automated software development tools like Matrix-X. And I'm sure that there are better tools now. But flight computer hardware and software typically account for 5-10% of total development cost. So saving 10 or 20% on this cost doesn't change the bottom line significantly. As far as "off-the-shelf" hardware, I'm not aware of any that could be used in a new vehicle like the CEV without significant modification. Spacecraft and launch vehicle designers and program managers have enough problems without trying to shoehorn "alien" hardware into their designs. [...] > indicating that the mode of reentry (capsule/parachute, lifting > bodies/runway, or shuttle orbiters/runway) is not a strong driver of [quoted text clipped - 6 lines] > development and for 12 Block I vehicles, 23 Block IIs and 20 boilplate > units. Interesting. Does this point the finger at Systems Integration, or other parts of the design process? Do you have a quick note of the breakdown between development and manufacturing? How much of the Shuttle's $14B was spent on test articles (trying to make a fair comparison, though we didn't do a lot of STS boilerplates)? /dps I > [...] > > indicating that the mode of reentry (capsule/parachute, lifting [quoted text clipped - 17 lines] > make a fair comparison, though we didn't do a lot of STS > boilerplates)? The best info I have is from the NASA budget documents for FY73 thru FY00 (in $M Y2K) Orbiter DDT&E (FY 73 - 82) $14,049 Orbiter Production (FY 1978-82) $4,398 Shuttle Production & Operation Capability - Orbiter (FY 1983-89) $5,538 Orbiter Operational Capability and Flight Hardware (1990-91) $1,445 Shuttle Operations - Orbiter (1992 - 96) $2,360 Shuttle Operations - Orbiter & Integration (1997-00) $2,351 Total $30,141 I don't think this answers your question. Later Ray Schmitt Question: When one complains about Shuttle's exhorbitant launch costs of about $400 million per launch, does that include the astronaut programme costs, as well as KSC and all the staff at mission control in Houston (and those behind the scenes) ? Or is it only the costs of processing the shuttle and bringing it to pad and fueling it ? If it includes all of the manned space programme costs, then will switching from Shuttle to the virtual CEV really reduce costs that much ? >When one complains about Shuttle's exhorbitant launch costs of about $400 >million per launch, does that include the astronaut programme costs, as well [quoted text clipped - 5 lines] >If it includes all of the manned space programme costs, then will switching >from Shuttle to the virtual CEV really reduce costs that much ? Futher the entire manned program less the ISS is near 5 billion dollars a year. How dooes that translate into so many million per sshuttle launch since the ONLY manned operation we have after backing out the costs of ISS is the shuttle. Just what dont I get here? >Just what dont I get here? I tried to make a list; but even with over 8 gig free on my HD when I started, I got a 'disk full' error. D. SignatureTouch-twice life. Eat. Drink. Laugh. >I tried to make a list; but even with over 8 gig free on my HD when I >started, I got a 'disk full' error. > >D. Well lets just list the high points shall we. Again take the entire manned space budget backout the ISS and what remains must be shuttle or shuttle related. >>I tried to make a list; but even with over 8 gig free on my HD when I >>started, I got a 'disk full' error. > >Well lets just list the high points shall we. Nope, still got the 'disk full' error. >Again take the entire manned space budget backout the ISS and what remains must >be shuttle or shuttle related. Except for all the things that aren't. D. SignatureTouch-twice life. Eat. Drink. Laugh. >>Again take the entire manned space budget backout the ISS and what remains >must >>be shuttle or shuttle related. > >Except for all the things that aren't. WHICH IS:( >Actually, Derek, many of those who have been shuttle supporters for a >long time have been slowly picking up on what the capsule people have [quoted text clipped - 3 lines] >designs, let DOD do a scram jet, and then revisit winged vessels when >we have better materials and/or design. Putting it off won't make it easier, especially considering that the real problems have nothing to do with TPS designs or scram jets. >Seperately, many of us who have been reusable space craft supporters >for a long time have been slowly picking up on what the expendable [quoted text clipped - 3 lines] >rate up on a pay-as-you go basis, and then use those reliable >components in steps to getting back to reusable craft. The problem is; expendables with any significant capability won't be cheap either. All you are saying is Apollo was cool, the Shuttle sucks, so let's avoid re-useables. The key to lowering expenses is reducing the standing army, which applies regardless of winged or not, expendable or not. The next key is lowering capital expenses, which is difficult to do with expendables unless you have a fairly high flight rate resulting in mass production. Ultimately, achieving CATS isn't about engineering, it isn't about cheap spacecraft. It's about managing capital, it's about designing systems and processes, it's about a metric buttload of things that have nothing to do with bending metal or pumping fuel. CATS supporters ignore this at their peril. >The shuttle is sexy, major impressive, and has done things that Apollo >designers would give right arms for. But it requires heroic efforts [quoted text clipped - 3 lines] >step closer; DC-X was a step closer; Falcon-V and Spaceship One are >steps closer. Maybe Kliper is a step closer. Maybe, maybe not. A lot of things can happen between prototypes and viewgraphs and an operational spaceline. >200-series orbiters are possible. But they would be only an >incremental improvement in design, and Big Bucks items as much as Buck >Rogers. Capsules designs on make significant advances over Apollo for >better bang for the Big Bucks. And in the end, you wrap up with the same statement you started. Apollo was cool, therefore capsules are cool, the Shuttle sucks, therefore winged vehicles suck. D. SignatureTouch-twice life. Eat. Drink. Laugh. [...] > Putting it off won't make it easier, especially considering that the > real problems have nothing to do with TPS designs or scram jets. So what are the real problems with winged vehicle design, and how can we address them in a timely manner? [Also, don't be lead astray by my mentioning scram jets -- in this context, they are just a way to test TPS] [...] > The key to lowering expenses is reducing the standing army, which > applies regardless of winged or not, expendable or not. The next key > is lowering capital expenses, which is difficult to do with > expendables unless you have a fairly high flight rate resulting in > mass production. Which is the point about buying LVs that other people are buying; Ariane and Semayorka aren't currently acceptable answers when NASA pitches to Congress, but we do have a couple choices. > Ultimately, achieving CATS isn't about engineering, it isn't about > cheap spacecraft. It's about managing capital, it's about designing > systems and processes, it's about a metric buttload of things that > have nothing to do with bending metal or pumping fuel. CATS > supporters ignore this at their peril. Indeed. > >The shuttle is sexy, major impressive, and has done things that Apollo > >designers would give right arms for. But it requires heroic efforts > >to be usable. Apollo required heroic efforts. But the route to CATS > >requires something where heroic is too much. The fabled "airliner > >flight-line turnaround" is part of the discussion, and EELVs are a > >step closer; [...] Look up above, where you said > The key to lowering expenses is reducing the standing army, which > applies regardless of winged or not, expendable or not. Compared to the Shuttle, and probably to S-V, you'll find D4 and A5 are way ahead on this. And the Shuttle's standing army goes to reusable components (TPS, SSMEs, and SRBs). > And in the end, you wrap up with the same statement you started. > Apollo was cool, therefore capsules are cool, the Shuttle sucks, > therefore winged vehicles suck. No, I think the Shuttle is cool, and I'd join the ride to HST if I could. The Shuttle's ability to Bring Things Back is unparalled, and I'm watching to see how this problem gets solved in the next generation. It *will* be an important issue for serious Moon work, not to mention sample returns from Mars. The Problem with the Shuttle is that it is at the edge of things that we know how to do, especially in terms of reentry, and (possibly from being at the edge) requires a huge standing army. A CEV using a capsule would have a much smaller standing army, part of which would be shared by DOD and other customers, and the LV is much closer to mass production. Actually, I'd be interested in hearing how a lifting body CEV might measure up, like some of the Kliper-related pics, or HL-20. It seems that the TPS issues are more manageable there because LBs have fewer hot spots than winged vehicles do. I'm definitely not having a knee-jerk reaction against WVs; it took a lot of persuasion to get me to see the above viewpoint. It is true that one design or the other goes in or out of fashion at various times. In the long run, I think we need to do both (though not always at the same time) in order to actually get past our current limitations. /dps > Compared to the Shuttle, and probably to S-V, you'll find D4 and A5 > are way ahead on this. And the Shuttle's standing army goes to > reusable components (TPS, SSMEs, and SRBs). The question shouldn't be "how many people are assigned to maintaining the shuttle" but rather "does maintaining reusable vehicle require more manpower than building a new vehicle for each launch". And you can then break this down. NASA decided early on that it wasn't worth building a reusable ET. Is it worth re-using SRBs ? Should they design a more powerful set of SRBs which would allow the use of an off-the-shelf disposable engine for the shuttle ? Would this reduce overall costs ? What portion of Shuttle's "exhorbitant" costs are associated with the shuttle itself versus the fact that the shuttle transports humans ? It is easy to say that some delta rocket is much much cheaper than a shuttle. But if you start to add the costs to man-rate the rocket as well as provide man-rated crew capsule for each launch, would this really be so much cheaper than shuttle ? Another isseu: NASA essentially had 4 shuttles to play with and they were expected to last forever and no ability to build new ones because tooling was gone. What if each 200 series shuttle were rated only for a certain number of flights, and the production line would spit out a new shuttle every 4 or 5 years ? (possibly implementing continueal improvements) ? >What if each 200 series shuttle were rated only for a certain number of >flights, and the production line would spit out a new shuttle every 4 or 5 >years ? (possibly implementing continueal improvements) ? You would not reduce costs that much. You reduce costs by eliminating overhead and amortizing what cannot be eliminated across as many flights as possible. You reduce costs by marrying a properly designed vehicle with a well designed operational concept, then managing it and accounting for it by well known and well proven techniques. You fly the hell out of each craft and retire it only when maintenance costs begin to be a disproportionate amount of total operating cost. (Ask any CPA for the formulas to determine what that point is). 99% of the stuff discussed here covers only the first 1% of what is a large and involved process. All the PHB stuff that makes the difference is handwaved away. D. SignatureTouch-twice life. Eat. Drink. Laugh. > The Shuttle's ability to Bring Things Back is unparalled, and I'm > watching to see how this problem gets solved in the next generation. > It *will* be an important issue for serious Moon work, not to mention > sample returns from Mars. This is the one truly unique capability that such a huge re-entry vehicle gives you. But is it really necessary? What do you *need* to bring back from the moon besides people and scientific samples? What *need* could possibly justify a re-entry vehicle with a 15 foot by 60 foot payload bay? At a minimum, you could build a RV small enough to fit the desired crew size and simply fly it unmanned for scientific sample return. If there truly is a need to return cargo bigger than this, a separate RV for cargo may be a good idea, since one of the biggest problems with the shuttle is its many capabilities made possible by hardware that must fly on every flight. Jeff SignatureRemove "no" and "spam" from email address to reply. If it says "This is not spam!", it's surely a lie. > > The Shuttle's ability to Bring Things Back is unparalled, and I'm > > watching to see how this problem gets solved in the next generation. [quoted text clipped - 6 lines] > *need* could possibly justify a re-entry vehicle with a 15 foot by 60 > foot payload bay? As the size of the scientific samples grow, the Apollo-size cargo bay becomes more of a constraint. And while I'm not holding my breath for manufacturing on the moon (besides, the target market for that would probably *not* be on Earth), there will at some time be fabricated items that need to be sent back. > At a minimum, you could build a RV small enough to fit the desired > crew size and simply fly it unmanned for scientific sample return. If > there truly is a need to return cargo bigger than this, a separate RV > for cargo may be a good idea, since one of the biggest problems with > the shuttle is its many capabilities made possible by hardware that > must fly on every flight. Yes, that would work. I think it needs to be a plan underway in parallel with CEV. Would a lifting body work for unmanned ops like this? I would guess that automated control would make the answer yes, but are there gotchas to implementing that on lifting bodies? /dps >As the size of the scientific samples grow, the Apollo-size cargo bay >becomes more of a constraint. And while I'm not holding my breath for >manufacturing on the moon (besides, the target market for that would >probably *not* be on Earth), there will at some time be fabricated >items that need to be sent back. If you are doing EOR, then being able to ship significant sized pieces back for repair/refurbishment becomes attractive. D. SignatureTouch-twice life. Eat. Drink. Laugh. >>As the size of the scientific samples grow, the Apollo-size cargo bay >>becomes more of a constraint. And while I'm not holding my breath for [quoted text clipped - 4 lines] > If you are doing EOR, then being able to ship significant sized pieces > back for repair/refurbishment becomes attractive. We are starting to see that now with ISS, in fact. ISS has lost one of its four CMGs and there is a growing suspicion that the failure mode may be generic. NASA would *really* like to get that failed CMG on the ground to determine the root cause, but the shuttle is the only existing vehicle capable of returning it. SignatureJRF Reply-to address spam-proofed - to reply by E-mail, check "Organization" (I am not assimilated) and think one step ahead of IBM. >derekl1963@nospamyahoo.com (Derek Lyons) wrote in >> If you are doing EOR, then being able to ship significant sized pieces >> back for repair/refurbishment becomes attractive. [quoted text clipped - 4 lines] >determine the root cause, but the shuttle is the only existing vehicle >capable of returning it. Is there some reason this can't be done with the remaining flights? Won't the mission that carries up a replacement CMG return with the old one? Maybe you're just using this as an example of things that may not be possible post-shuttle, but "would really like to..." sounds to me like they are unable to do it and are somewhat frustrated by that. Dale >>derekl1963@nospamyahoo.com (Derek Lyons) wrote in > [quoted text clipped - 10 lines] > Won't the mission that carries up a replacement CMG return with the > old one? Yes, but you'll notice the shuttle fleet isn't flying right now... SignatureJRF Reply-to address spam-proofed - to reply by E-mail, check "Organization" (I am not assimilated) and think one step ahead of IBM. "Jorge R. Frank" would *really* like to get that failed CMG on the ground to > determine the root cause The gyros on the Hubble have been failing routinely for years. How complicated could it be? The bearings fail. You remove the bearing and install a replacement. Half hour job. Except the ones on ISS are probably not field replaceable since they weren't supposed to fail. I dunno anything about the gyros except that they fail a lot. >"Jorge R. Frank" > would *really* like to get that failed CMG on the ground to [quoted text clipped - 5 lines] >not field replaceable since they weren't supposed to fail. I dunno anything >about the gyros except that they fail a lot. So how is it that you've managed to diagnose the problem and call it a half hour job (assuming field-replaceable bearings)? Seems like they could have had one running on the ground all this time as a test article that would be closer to home for analysis, should it fail as well. But I suppose budgets don't permit such luxuries... Dale > Seems like they could have had one running on the ground all this > time as a test article that would be closer to home for analysis, > should it fail as well. But I suppose budgets don't permit such > luxuries... Not that it would prove much either, the ground CMG being neither in zero-G nor a vacuum. SignatureJRF Reply-to address spam-proofed - to reply by E-mail, check "Organization" (I am not assimilated) and think one step ahead of IBM. >>"Jorge R. Frank" >> would *really* like to get that failed CMG on the ground to [quoted text clipped - 12 lines] > time as a test article that would be closer to home for analysis, should > it fail as well. But I suppose budgets don't permit such luxuries... I don't know what is on the ground for life testing or what was done for qualification in this case or if it is bearings, however, note that testing on the ground does not always equal operations in space, particular for mechanical devices and lubricants. From the Skylab experience: <Skylab> Skylab Lesson #40. Lesson: Lubrication of Rotating Machinery If possible, positive lubrication methods should be included in the design of long-life rotating machinery, such as control moment gyros. Background: Two of the Skylab CMG's experienced bearing anomalies (temperature increases) and one (CMG #1) failed on day 194. Analysis indicates that poor lubrication caused bearing failure. The CMG's were designed with an automatic lubrication metering system which was chosen to minimize the need for active control, to maximize bearing life, and to prevent contamination by containing all oil. Life tests conducted on the ground far exceeded the required life. In retrospect, it appears as if the forces on the oil in zero gravity caused it to seek different locations than in one-g where full lubrication was possible. Since fluid flow In zero-g is not yet fully understood, it appears prudent to design a system with positive control. </Skylab> Signaturerk, Just an OldEngineer "For a successful technology, reality must take precedence over public relations, for nature cannot be fooled." -- R. Feynman, Appendix F. > "Jorge R. Frank" > would *really* like to get that failed CMG on the ground to >> determine the root cause > > The gyros on the Hubble have been failing routinely for years. How > complicated could it be? The bearings fail. You've assumed a particular diagnosis here. HST gyros != ISS CMGs. > You remove the bearing > and install a replacement. Half hour job. Except the ones on ISS are > probably not field replaceable since they weren't supposed to fail. Right, they're not EVA-servicable. So it's a lot longer than a half-hour job, and a lot more dangerous. And if your bearing diagnosis proves to be wrong, you get to go through the whole exercise again. Nice try, no cigar. SignatureJRF Reply-to address spam-proofed - to reply by E-mail, check "Organization" (I am not assimilated) and think one step ahead of IBM. >> The Shuttle's ability to Bring Things Back is unparalled, and I'm >> watching to see how this problem gets solved in the next generation. [quoted text clipped - 6 lines] >*need* could possibly justify a re-entry vehicle with a 15 foot by 60 >foot payload bay? It's not so much that the cargo bay is needed on the way down, but that it's needed on the way *up*. The ability to launch a payload *and a crew to assemble and install it* has so far shown itself to be pretty useful. >At a minimum, you could build a RV small enough to fit the desired >crew size and simply fly it unmanned for scientific sample return. If >there truly is a need to return cargo bigger than this, a separate RV >for cargo may be a good idea, since one of the biggest problems with >the shuttle is its many capabilities made possible by hardware that >must fly on every flight. Agreed. The ultimate problem with our current space transportation system is that it's built around a mini-van towing a camping trailer. There is no Ford Escort, no 18-wheeler, no buses.... D. SignatureTouch-twice life. Eat. Drink. Laugh. >[...] >> Putting it off won't make it easier, especially considering that the >> real problems have nothing to do with TPS designs or scram jets. > >[Also, don't be lead astray by my mentioning scram jets -- in this context, >they are just a way to test TPS] In any context they have zip point nada to do with TPS. <remainder of reply filled with equally ludicrous fallacies snipped.> >it took a lot of persuasion to get me to see the above viewpoint. You don't have a viewpoint. You have a dogma. You claim to "not have a knee jerk reaction against WV's", yet each of your examples list the Shuttle and it's problems as being those of all winged vehicles. D. SignatureTouch-twice life. Eat. Drink. Laugh. > >[...] > >> Putting it off won't make it easier, especially considering that the [quoted text clipped - 6 lines] > > <remainder of reply filled with equally ludicrous fallacies snipped.>\ Derek, I suspect you of not paying attention. A scram-jet equipped cruise vehicle has a lot of need for TPS. Any TPS which works for such a vehicle would work for reentry (that's a paraphrase of Henry, I think). > >it took a lot of persuasion to get me to see the above viewpoint. > [quoted text clipped - 3 lines] > > D. No, Derek, you have a knee-jerk reaction against criticism of WVs. The shuttle is the only WV design to have flown with any success, and the OPS winged vehicle designs are very sexy, but have very difficult issues with thermal problems of reentry. When these problems can be solved, I think WVs will be ready for a comeback. There are other problems with the shuttle that the OPS designs *do* deal with (side mount, for instance), but they are not the show stopper that TPS is. Note Henry's observations that smaller WVs tend to have more thermal problems due to planform loading considerations. You also did not answer my question about what *you* see as the issues with WVs and how they can be solved, you just made the World Weekly News statement that "Putting it off won't make it easier, especially considering that the real problems have nothing to do with TPS designs...." /dps > No, Derek, you have a knee-jerk reaction against criticism of WVs. > The shuttle is the only WV design to have flown with any success, and > the OPS winged vehicle designs are very sexy, but have very difficult > issues with thermal problems of reentry. When these problems can be > solved, I think WVs will be ready for a comeback. WVs will make a comeback when the mission requirements are best met by a WV design. I think it's important to state here that winged vehicles lost out in the OSP trade studies because of weight and abort issues. Both contractors felt enormous internal pressure to make their designs fit on the smallest (read "most economical") versions of both EELVs. Using capsule designs met that need. Both teams also found that a capsule design would provide 100% abort capability during ascent, something not true of the WVs they had developed. There were no internal concerns about TPS for the designs. > There are other problems with the shuttle that the OPS designs *do* > deal with (side mount, for instance), but they are not the show > stopper that TPS is. Note Henry's observations that smaller WVs tend > to have more thermal problems due to planform loading considerations. TPS is not a "show stopper". There are a number of TPS solutions available now. Remember that spacecraft design is driven by *mission requirements*. Had NASA specified some key mission requirement that could only be handled by a WV, then that's what you would have seen the teams move forward with. Winged vehicles have their advantages and disadvantages, just as capsules do. Attempts to rank one above another mean nothing without stating what the mission requirements are. -Kim- > OSP trade studies because of weight and abort issues. Both contractors felt > enormous internal pressure to make their designs fit on the smallest (read > "most economical") versions of both EELVs. What motivation was behind that "internal pressure" ? Doesn't that mean that the contractors had vested intetests that perhaps didn't match NASA's real needs ? > Using capsule designs met that > need. Both teams also found that a capsule design would provide 100% abort > capability during ascent, something not true of the WVs they had developed. Is this a winged vs capsule issue, or a reusable vs not reusable issue ? What if a winged vehicle were mounted on top of a stack instead of attached to its side ? Wouldn't that give it the same abort capabilities ? (In an abort scenario, must a reusable vehicle be completely saved or is it acceptable to lose it, while saving occupant's lives ? In an abort scenario, it is realistic to even assume that a normally reusable vehicle would be intact enough to be reusable ? > TPS is not a "show stopper". There are a number of TPS solutions available > now. Apart for what is used on the Shuttle, what other technologies exist ? If one were to build Shuttle mark II, how different would the TPS system be ? Same materials, but larger tiles due to better manufacturing techniques allowing more complex 3d shapes ? > Remember that spacecraft design is driven by *mission requirements*. Alpha isn't the first, nor will it be the last LEO space station. Heck, even Star Trek has space stations and ship assembly in orbit :-) The US space station isn't even finished yet and there is already a need to bring back stuff other than rubbish. That need will grow. And if you start building a ship to mars, you'll also need bidirectional transport because during building, stuff will fail and you will want it analysed to make sure that you fix the problems before the ship departs for its long voyage. > NASA specified some key mission requirement that could only be handled by a > WV, then that's what you would have seen the teams move forward with. Well, you mentioned that contractors have internal pressures to use EELVs (probably because one solution fits both NASA and commercial launches). Sounds to me like there is a lot of brainwashing being done to smear Shuttle style approach and NASA is just gulping it all in, believing it all. > Winged > vehicles have their advantages and disadvantages, just as capsules do. > Attempts to rank one above another mean nothing without stating what the > mission requirements are. Well, that brings the big question which NASA seems to have really avoided: WHAT ARE THE REQUIREMENTS ????? Since a trip to Mars is being discussed, does anyone really think that they could launch it all in one piece and that assembly and a shakedown would not be required in orbit prior to the trip actually starting ? Can NASA develop automated docking on hatches the size of CBM (they learned from MIR that smaller russian hatches are not good enough). ? Will truss structures assemble themselves automatically ? Will an arm fly by itself and attach itself to the station automatically ? If you're going to limit yourslef to camping trips to the moon, to re-enact Apollo, then yes, capsules are all that you need. But if you are going to move forwards, you need a truck to bring your materials to space for intelligent assembly. And during the shakedown, you need to bring back failed pieces for analysis. > > [quoted text clipped - 14 lines] >Bleh. > NASA managment is running scared after this accident. not a good way to press forward with the space program. | > that the Crew Exploration Vehicle (CEV), the space agencies latest and | > greatest orbiter replacement, will cost $15B to develop. [quoted text clipped - 26 lines] | are still manufactured (tiles, engines and I am sure countless other | components that are regularly replaced). Hmm, if all you wanted was a one size fits all solution, as per the current Shuttle, then I guess you could do this, but from what I read, this is not what is wanted now. Times and ways of doing stuff change with the benefit of hindsight... So, how can you add a crew escape option to the current design?Do you really want to carry huge items to orbit with humans in the same vehicle? As for advances in technology, you do have much smaller electronics and with a better capability, you also have considerable experience with composites for rigid structures. However, as for the real hardware, like engines and stuff, it seems as if the problems are now better understood, but the solutions are not going to be any cheaper, unless you want throw away engines, and even then, by definition, you are in effect reducing reliablity, as you are not designing for long running times are you? Personally, I see crew transport as just that, maybe with enough tools to do jobs with, but even this may be best done with some kind of space based service vehicle, which would never need to return, and thus could be designed woth the task it was needed for paramount. I'd be real interested to see how the one big problem is solved though, wherever you go, y ou need fuel, and at the moment it all has to be hauled up from Earth. It is not going to be cheap to keep on doing this,scpecially if you want a moon base! Brian -- Brian Gaff....Note, this account does not accept Bcc: email. graphics are great, but the blind can't hear them Email: briang1@blueyonder.co.uk ____________________________________________________________________________ __________________________________ > Hmm, if all you wanted was a one size fits all solution, as per the current > Shuttle, then I guess you could do this, but from what I read, this is not > what is wanted now. Times and ways of doing stuff change with the benefit of > hindsight... What is wanted is the Enterprise with its light-speed capable shuttles, transparent aluminium windows, shields etc. What is wanted is $10 per pound launch costs. It is, in my opinion, unrealisting to expect to go from $10,000.00 down to $10.00 in just one generation of ship, unless you have made a very dramatic discovery in the meantime. (anti-gravity engines or whatever). So, unless/until you make a dramatic discovery, the best thing would be to fine tune your current systems, instead of totally re-inventing what will turn out to be the same thing with a different shape. > So, how can you add a crew escape option to the current design?Do you really > want to carry huge items to orbit with humans in the same vehicle? is crew escape really necessary ? Or is is just a requirement inserted in there to eliminate a shuttle-like solution ? Are cars equipped with ejection seats in case the brake system fails while car is barreling down a long hill with a steep curve at the bottom ? NASA hasn't revealed much about the crew cabin of Columbia. *IF* just protecting the aft bulkhead with thermal blankets would have been sufficient to shield the crew from the fire (and proper use of suits to keep them alive with O2 until low enough altitude), is there really a need for an escape system that can be used during re-entry ? And as far as Challenger is concerned, since it seems that the crew cabin did survive the explosion, wouldn't current bailout procedures (had they been implemented back then) have made it possible to survive this ? > As for advances in technology, you do have much smaller electronics and > with a better capability, you also have considerable experience with > composites for rigid structures. That is just fine tuning. None of those will give you the dramatic cost reductions. None of the current "new" technologies in the works (ion drive, nuclear engines) are usable at launch. So perhaps what is needed is to use a conventional space truck to bring s |
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