pittman@mwk.uucp (05/02/91)
Is Endeavour (OV-105) the absolutely last shuttle to be built? Everything I hear seems to indicate that, yet common sense tells me that with Freedom going up over the next decade, the current shuttle fleet may be too old to service it. The older spacecraft are already about ten years old; that means that at the point that Freedom becomes operational, Columbia would be approaching twenty years of age. The youngest orbiter, Endeavour, would then be pushing ten. Pardon my naivete, but what is the design lifetime of a shuttle orbiter? ------------------------------------------------------------- --- Darrell Pittman pittman@mwk.uucp --- --- M. W. Kellogg Co. pittman%mwk@lobster.hou.tx.us --- --- Houston, TX (713) 753-4410 --- -------------------------------------------------------------
pstinson@pbs.org (05/03/91)
In article <346.281f448d@mwk.uucp>, pittman@mwk.uucp writes: > Is Endeavour (OV-105) the absolutely last shuttle to be built? It will probably be the last of the Enterprise class of space shuttles to be built, but it will not be the last space shuttle to go into service. Space Station Freedom will eventually be visited by a new generation of space shuttle, possibly a single stage to orbit design that will emerge from the NASP project. There are also two stage designs being considered. We must keep in mind the current shuttle design was drawn up nearly twenty years ago and it is time to take note of what we have learned from it and move on to the next class. Intrepid?
fcrary@lightning.Berkeley.EDU (Frank Crary) (05/04/91)
In article <346.281f448d@mwk.uucp> pittman@mwk.uucp writes: >Pardon my naivete, but what is the design lifetime of a shuttle orbiter? According to the Office of Technology Assessment, the Shuttle system will need to be replaced in the 2000-2010 frame. NASA Langley is working on design concepts for a Shuttle II, now called AMLS or Advanced Manned Launch System, these studies include everything from just like the Shuttle but with a fly-back payload to a Hermes-like spaceplane on a beafed up Titan to a air-launched system similar to the German Sanger II concept. However, by 2010, a NASP (X-30, fly to orbit, land and take off like a 747) derived cargo and passenger carrier may be available. As far as operating the space station, almost anything will do. The soviet station is supported by a Delta-class launcher. Frank Crary UC Berkeley
henry@zoo.toronto.edu (Henry Spencer) (05/05/91)
In article <346.281f448d@mwk.uucp> pittman@mwk.uucp writes: >Is Endeavour (OV-105) the absolutely last shuttle to be built? ... Debatable point. NASA now tends to side with the Rogers Commission, the NRC, the OTA, and others who have studied the issue, in believing that an ongoing supply of new orbiters is needed to keep the shuttle fleet viable in the face of accidents and wear. Unfortunately, the Augustine Commission recommended against it, and Congress is hostile to the extra expense. At the moment, the farthest things are going is construction of a new set of "structural spares" (the old set having been used to build Endeavour). >Pardon my naivete, but what is the design lifetime of a shuttle orbiter? Theoretically, I believe it was set at something like 200 flights. Nobody knows, yet, whether that has any relation to reality. -- And the bean-counter replied, | Henry Spencer @ U of Toronto Zoology "beans are more important". | henry@zoo.toronto.edu utzoo!henry
henry@zoo.toronto.edu (Henry Spencer) (05/05/91)
In article <1991May3.120004.12584@pbs.org> pstinson@pbs.org writes: >... it will not be the last space shuttle to go into service. Space >Station Freedom will eventually be visited by a new generation of space >shuttle... Freedom will be in a museum, or in pieces strewn over Australia :-), before NASA gets funding to build a second-generation shuttle. >time to take note of what we have learned from it and move on to the next >class... Very true. We should have been moving on it years ago, in fact. No sign of motion yet. -- And the bean-counter replied, | Henry Spencer @ U of Toronto Zoology "beans are more important". | henry@zoo.toronto.edu utzoo!henry
henry@zoo.toronto.edu (Henry Spencer) (05/05/91)
In article <1991May4.081930.14921@agate.berkeley.edu> fcrary@lightning.Berkeley.EDU (Frank Crary) writes: >However, by 2010, a NASP (X-30, fly to orbit, land and take off like >a 747) derived cargo and passenger carrier may be available. The operative word, of course, is "may". I give the X-30 itself only a 50% chance of flying by then, although the recent revival of military interest in it may help. -- And the bean-counter replied, | Henry Spencer @ U of Toronto Zoology "beans are more important". | henry@zoo.toronto.edu utzoo!henry
heskett@titan.tsd.arlut.utexas.edu (Donald Heskett) (05/05/91)
Henry Spencer (henry@zoo.toronto.edu) says: > I give the X-30 itself only a 50% chance of flying by [2010], although > the recent revival of military interest in it may help. Why so pessimistic? Most of the reports so far in "Aviation Week" about the progress of NASP seem to be that research is going better than expected. I don't remember ever hearing this before about any other major vehicle.
henry@zoo.toronto.edu (Henry Spencer) (05/05/91)
In article <HESKETT.91May4202553@polymnia.titan.tsd.arlut.utexas.edu> heskett@titan.tsd.arlut.utexas.edu (Donald Heskett) writes: >> I give the X-30 itself only a 50% chance of flying by [2010]... > >Why so pessimistic? Most of the reports so far in "Aviation Week" >about the progress of NASP seem to be that research is going better >than expected... Technically the program is in fine shape. But by X-plane standards it is staggeringly expensive. Congress is increasingly reluctant to spend that much on a pure research project, and the White House is correspondingly reluctant to ask for it. The X-30 effort has already been hit with "you may be ready to build it but we're not ready to pay for it; go away and improve the technology for a few years and ask us again" once. It would not be at all surprising if this happens repeatedly. -- And the bean-counter replied, | Henry Spencer @ U of Toronto Zoology "beans are more important". | henry@zoo.toronto.edu utzoo!henry
fcrary@lightning.Berkeley.EDU (Frank Crary) (05/05/91)
In article <1991May4.213944.7721@zoo.toronto.edu> henry@zoo.toronto.edu (Henry Spencer) writes: >The operative word, of course, is "may". I give the X-30 itself only a 50% >chance of flying by then, although the recent revival of military interest >in it may help. If I remember the timetables correctly, the X-30 is supposed to make its first flight in 1996, with its first orbital flight in 1997. (Assuming, of course Congress funds it.) If the program was to run 13 full years late, it would still fly by 2010. The credibility of the X-30 timetables is now (as of January) much better. Instead of assuming the availability of materials and technology that have not yet been developed, they have frozen the X-30's technology at the 1990 level. As a result, all the things they are assuming for a 1 first flight are known to be there. Frank Crary UC Berkeley
bjax@grissom.larc.nasa.gov ( Bruce Jackson) (05/05/91)
In article <1991May4.213743.7574@zoo.toronto.edu> henry@zoo.toronto.edu (Henry Spencer) writes: >In article <1991May3.120004.12584@pbs.org> pstinson@pbs.org writes: >>... it will not be the last space shuttle to go into service. Space >>Station Freedom will eventually be visited by a new generation of space >>shuttle... > >Freedom will be in a museum, or in pieces strewn over Australia :-), before >NASA gets funding to build a second-generation shuttle. Funding is decided by Congress; but you might be interested to know NASA- Langley is developing a "space taxi" based on lifting body technology that is capable of carrying up to ten people to low earth orbit. If funding for further development is approved, we could be on the road to a shuttle adjunct, that could serve as the "lifeboat" for the space station. -- Bruce Jackson <bjax@grissom.larc.nasa.gov> NASA Langley Research Center MS 489, Hampton, VA 23665 (804) 864-4060
mvk@aix01.aix.rpi.edu (Michael V. Kent) (05/06/91)
In article <1991May5.082711.25435@agate.berkeley.edu> fcrary@lightning.Berkeley.EDU (Frank Crary) writes: >If I remember the timetables correctly, the X-30 is supposed to make its first >flight in 1996, with its first orbital flight in 1997. (Assuming, of course >Congress funds it.) If the program was to run 13 full years late, it would >still fly by 2010. From what I can tell, the most recent information regarding the X-30 is as follows: Preliminary design is currently underway and will proceed until 1993. At that time a decision will be made whether to build two test vehicles. Cost of the two planes is estimated at $8 to $12 billion. If funded, first flight of the X-30 will be in late 1997 / early 1998, with an orbital attempt some- time in 1999. Mike -- Michael Kent mvk@itsgw.rpi.edu McDonnell Douglas Rensselaer Polytechnic Institute All facts in this post are based on publicly available information. All opinions expressed are solely those of the author. Official positions may vary.
aws@iti.org (Allen W. Sherzer) (05/07/91)
In article <346.281f448d@mwk.uucp> pittman@mwk.uucp writes: >Is Endeavour (OV-105) the absolutely last shuttle to be built? With luck, yes. >Everything >I hear seems to indicate that, yet common sense tells me that with Freedom >going up over the next decade, the current shuttle fleet may be too old to >service it. Freedom can be serviced for a tenth the cost using expendables. With no more new shuttles, NASA will need to use them. The taxpayers will save billions if they do. >Pardon my naivete, but what is the design lifetime of a shuttle orbiter? I think it is 100 flights. Allen -- +---------------------------------------------------------------------------+ |Allen W. Sherzer | Allen's tactics are too tricky to deal with | | aws@iti.org | -- Harel Barzilai | +---------------------------------------------------------------------------+
henry@zoo.toronto.edu (Henry Spencer) (05/07/91)
In article <1991May5.122325.24559@news.larc.nasa.gov> bjax@grissom.larc.nasa.gov ( Bruce Jackson) writes: >>Freedom will be in a museum, or in pieces strewn over Australia :-), before >>NASA gets funding to build a second-generation shuttle. > >Funding is decided by Congress; but you might be interested to know NASA- >Langley is developing a "space taxi" based on lifting body technology that >is capable of carrying up to ten people to low earth orbit... No, Langley is not "developing" it. Langley is studying the possibility of submitting a proposal to investigate maybe someday developing it. Or words to that effect. :-) For all the hoopla about that project, its funding is miniscule -- it's just another design study, and could easily sink without trace like a lot of other NASA design studies. -- And the bean-counter replied, | Henry Spencer @ U of Toronto Zoology "beans are more important". | henry@zoo.toronto.edu utzoo!henry
fcrary@lightning.Berkeley.EDU (Frank Crary) (05/07/91)
While the shuttle was designed to have a 100 flight lifetime (as well as fly 12 flights/year). However the Office of Technology Assessment notes that this would require a reliability of 99.97%. If you assume a more realistic reliability of 97.5% (one failure in 40 which is the current total), an orbiter has a 50% chance of being lost by its 27th flight. Frank Crary UC Berkeley
joefish@disk.uucp (joefish) (05/07/91)
In article <1991May6.170018.5455@iti.org> aws@iti.org (Allen W. Sherzer) writes: >In article <346.281f448d@mwk.uucp> pittman@mwk.uucp writes: >>Is Endeavour (OV-105) the absolutely last shuttle to be built? > >With luck, yes. > >>Everything >>I hear seems to indicate that, yet common sense tells me that with Freedom >>going up over the next decade, the current shuttle fleet may be too old to >>service it. > >Freedom can be serviced for a tenth the cost using expendables. With >no more new shuttles, NASA will need to use them. The taxpayers will >save billions if they do. > >>Pardon my naivete, but what is the design lifetime of a shuttle orbiter? > >I think it is 100 flights. > > Allen >-- >+---------------------------------------------------------------------------+ >|Allen W. Sherzer | Allen's tactics are too tricky to deal with | >| aws@iti.org | -- Harel Barzilai | >+---------------------------------------------------------------------------+ There are other things than fred to think about. I think it would be useful to build another shuttle, but without wings, without heat tiles, without rudder, and without landing gear, and use it to go to geo orbit and remove nonworking satellites, and bring them down to LEO and put them in a shuttle that can land them. The weight of the wings, tiles and rudder and landing gear, could be put into tanks and fuel for the orbital maneuvoring engines, and for extra oxygen and supplies. This special shuttle could be one step toward building interplanetary manned ships. There is not going to be much change in the cabin between present shuttles and any new craft for extended trips. If a shuttle craft like this were built, it's total weight would 7/*d2XnGahbe payload, and it would weigh close to 200,000 pounds. Why develop a new heavy lift system when one exists, but it isn't being used for heavy lifts, only for lifting the aerospace shuttle. I can't conceive of any need to lift anything in one piece heavier than 200,000 pounds, and the present shuttle system can do it. How many 200,000 pound cargos will there be during the next 30 years? Joe Fischer joefish@disk.UUCP
aws@iti.org (Allen W. Sherzer) (05/08/91)
In article <1991May07.054232.19990@disk.uucp> joefish@disk.uucp (joefish) writes: >>Freedom can be serviced for a tenth the cost using expendables. With >>no more new shuttles, NASA will need to use them. The taxpayers will >>save billions if they do. >There are other things than fred to think about. I think it would be >useful to build another shuttle, but without wings, without heat tiles, >without rudder, and without landing gear, and use it to go to geo orbit >and remove nonworking satellites, and bring them down to LEO and put >them in a shuttle that can land them. This sounds sort of like Shuttle-C although I doubt very much it could to to GEO. But you still have the same problem. The Shuttle is amazingly horendously mind-boggelingly expensive to operate. We would be far better off if we took this huge amount of money and spent it on infrastructure. We should build a reasonable OTV for going to GEO to get satellites. We should have a drydock in orbit for repair. The problem is that none of this will happen with the market so small and the market will remain small as long as we insist on spending three to five times what we need to to put payloads into orbit. Allen -- +---------------------------------------------------------------------------+ |Allen W. Sherzer | Allen's tactics are too tricky to deal with | | aws@iti.org | -- Harel Barzilai | +---------------------------------------------------------------------------+
mll@aio.jsc.nasa.gov (Mark Littlefield) (05/08/91)
In article <346.281f448d@mwk.uucp>, pittman@mwk.uucp writes: |> Is Endeavour (OV-105) the absolutely last shuttle to be built? Everything |> I hear seems to indicate that, yet common sense tells me that with Freedom |> going up over the next decade, the current shuttle fleet may be too old to |> service it. The older spacecraft are already about ten years old; that means |> that at the point that Freedom becomes operational, Columbia would be |> approaching twenty years of age. The youngest orbiter, Endeavour, would then |> be pushing ten. |> |> Pardon my naivete, but what is the design lifetime of a shuttle orbiter? |> |> |> ------------------------------------------------------------- |> --- Darrell Pittman pittman@mwk.uucp --- |> --- M. W. Kellogg Co. pittman%mwk@lobster.hou.tx.us --- |> --- Houston, TX (713) 753-4410 --- |> ------------------------------------------------------------- If I remember correctly, the shuttle was originally designed for a hundred cycles (flights). That number was based on a flight schedule of 1 flight a week, or a turn-around time of 4 weeks on a single orbiter so I'm not sure what the current projections are. Although we all love the shuttle, I doubt that it would last 100 years at an average rate of a little over one flight a year (the current average...counting the test program and Return to Flight). It's pretty clear that shuttle was a pathfinder and a true, one-stage-to-orbut vehicle will be needed to service Space Station Freedom and it's siblings. ===================================================================== Mark L. Littlefield Automation and Robotics Division internet: mll@aio.jsc.nasa.gov Intelligent Systems Branch USsnail: Lockheed Engineering and Sciences 2400 Nasa Rd 1 / MS 19 Houston, TX 77258 ====================================================================
smfedor@solar.lerc.nasa.gov (Gregory Fedor) (05/08/91)
In article <1991May7.173026.5258@iti.org> aws@iti.org (Allen W. Sherzer) writes: >In article <1991May07.054232.19990@disk.uucp> joefish@disk.uucp (joefish) writes: > >>>Freedom can be serviced for a tenth the cost using expendables. With >>>no more new shuttles, NASA will need to use them. The taxpayers will >>>save billions if they do. > >>There are other things than fred to think about. I think it would be >>useful to build another shuttle, but without wings, without heat tiles, >>without rudder, and without landing gear, and use it to go to geo orbit >>and remove nonworking satellites, and bring them down to LEO and put >>them in a shuttle that can land them. > >This sounds sort of like Shuttle-C although I doubt very much it could >to to GEO. Actually, it sounds more like the OMV (Orbital Maneuvering Vehicle?) that MSFC (Marshall Space Flight Center) was working on before it was axed by congress in a budget cut. Well, now that I think about it, what joefish described wouldn't resemble the OMV, but functionally they'd accomplish the same things. I don't remember too much about the OMV. Perhaps someone from MSFC could fill in the details. Too bad congress nixed it. It sounded like a good idea that _would_ work. -- =============================================================================== Gregory A. Fedor | Far from day, far from light \ Sverdrup Technology Inc. | Out of time, out of sight \ NASA Lewis Research Center | To a world, young and free \\-^-/___ Cleveland, Ohio 44135-3191 | Weep no more, follow me |===[o]/ #o (216) 433-8468 | /VVV smfedor@lerc01.lerc.nasa.gov | Forever...Forever...Forever / (128.156.10.14) | Voyagers 1 & 2 ===============================================================================
kent@vf.jsc.nasa.gov (05/08/91)
> > If I remember correctly, the shuttle was originally designed for a > hundred cycles (flights). That number was based on a flight schedule > of 1 flight a week, or a turn-around time of 4 weeks on a single > orbiter so I'm not sure what the current projections are. > > Although we all love the shuttle, I doubt that it would last 100 years > at an average rate of a little over one flight a year (the current > average...counting the test program and Return to Flight). It's > pretty clear that shuttle was a pathfinder and a true, > one-stage-to-orbut vehicle will be needed to service Space Station > Freedom and it's siblings. > Since the return to flight in 1988, each orbiter has flown about 3 times a year. It would be more realistic to count the flights per year based on a flight rate of 8-12 total flights a year. So.... 10 / 4 Orbiters = 2.5 flights a year per vehicle. The vehicles are rated at 100 flights. Plans are in work to assure parts and maintainablity thru the year 2020. Beyond that, I do not know. Assuming the year 2020 as the last shuttle flight: 29 years X 10 flights a year = 290 flights divided by 4 orbiters = 72.5 flight per vehicle plus about 10 flight each on Columbia , Discovery and Atlantis = 82.5 flights total. Now if all the Orbiters are still around after 82 flights each is another question entirely. Flying 40 year old vehicles in not unreasonable, The B52 fleet is nearing 30-40 years old. Also think of the average age of a DC3. The thought of flying 40 year old space technolgy is a scary one. -- Mike Kent - Lockheed Engineering and Sciences Company at NASA JSC 2400 NASA Rd One, Houston, TX 77058 (713) 483-3791 KENT@vf.jsc.nasa.gov
aws@iti.org (Allen W. Sherzer) (05/08/91)
In article <1991May8.144502.8308@eagle.lerc.nasa.gov> smfedor@solar.lerc.nasa.gov (Gregory Fedor) writes: >>This sounds sort of like Shuttle-C although I doubt very much it could >>to to GEO. >Actually, it sounds more like the OMV (Orbital Maneuvering Vehicle?) that >MSFC (Marshall Space Flight Center) was working on before it was axed by >congress in a budget cut. Actually, it sounds like a combination of Shuttle-C and OMV. >Too bad congress nixed it. It sounded like a good idea that _would_ work. It was NASA who nixed it. The program was cancled because it was way late and over budget. However, NASA has resurected it in the form of another vehicle (can't remember the name). They have stuck about $3 billion to NLDP to pay for it. With that kind of money don't expect it to do any better than OMV. There are things which can be done for a million $$ which can't be done for a billion $$. Allen -- +---------------------------------------------------------------------------+ |Allen W. Sherzer | Allen's tactics are too tricky to deal with | | aws@iti.org | -- Harel Barzilai | +---------------------------------------------------------------------------+
fcrary@headcrash.Berkeley.EDU (Frank Crary) (05/09/91)
In article <1991May8.092605.1@vf.jsc.nasa.gov> kent@vf.jsc.nasa.gov writes: >10 / 4 Orbiters = 2.5 flights a year per vehicle. The vehicles are rated at >100 flights. Plans are in work to assure parts and maintainablity thru the >year 2020. Beyond that, I do not know. > >Assuming the year 2020 as the last shuttle flight: 29 years X 10 flights a >year = 290 flights divided by 4 orbiters = 72.5 flight per vehicle plus about >10 flight each on Columbia , Discovery and Atlantis = 82.5 flights total. > >Now if all the Orbiters are still around after 82 flights each is another >question entirely. The 100 flight lifetime of an orbiter assumed an impossible reliability of 99.97%. The shuttle has demonstrated a 97.5% reliability (39 / 40 ). At this rate, there is only a 0.065% (e.g. 1543:1 against) chance of the shuttle fleet flying 290 missions without loosing an orbiter. In fact, at 97.5% reliability, 3 more flights in 1991 and 12/year in 1992 and later, there is only a 8.2% chance that all four orbiters will survive to see the year 2000. Also, there is a 35% chance that one of the 17 space station construction flights will result in an accident. I find it hard to see the shuttle still in use after 2010 (at the latest). Frank Crary UC Berkeley
rubinoff@linc.cis.upenn.edu (Robert Rubinoff) (05/09/91)
In article <1991May9.034143.16916@agate.berkeley.edu> fcrary@headcrash.Berkeley.EDU (Frank Crary) writes: >At this rate, there is only a 0.065% (e.g. 1543:1 against) chance of the >shuttle fleet flying 290 missions without loosing an orbiter. Actually, if they keep all the orbiters securely fastened, they won't be able to fly any missions! :-) Robert
kent@vf.jsc.nasa.gov (05/14/91)
In article <1991May9.034143.16916@agate.berkeley.edu>, fcrary@headcrash.Berkeley.EDU (Frank Crary) writes: >>Now if all the Orbiters are still around after 82 flights each is another >>question entirely. > > The 100 flight lifetime of an orbiter assumed an impossible reliability of > 99.97%. The shuttle has demonstrated a 97.5% reliability (39 / 40 ). > At this rate, there is only a 0.065% (e.g. 1543:1 against) chance of the > shuttle fleet flying 290 missions without loosing an orbiter. In fact, > at 97.5% reliability, 3 more flights in 1991 and 12/year in 1992 and later, > there is only a 8.2% chance that all four orbiters will survive to see the > year 2000. Also, there is a 35% chance that one of the 17 space station > construction flights will result in an accident. > > I find it hard to see the shuttle still in use after 2010 (at the latest). > > Frank Crary > UC Berkeley The true reliability of the shuttle is unknown. As you say is has demostrated 39/40. But, the shuttle vehicles are designed for to last 100 flights. The only think I see in your calculations is: You state the odds of all four vehicles surviving. What is the odds of one vehicle surviving 80 flights? -- Mike Kent - Lockheed Engineering and Sciences Company at NASA JSC 2400 NASA Rd One, Houston, TX 77058 (713) 483-3791 KENT@vf.jsc.nasa.gov
fcrary@lightning.Berkeley.EDU (Frank Crary) (05/16/91)
In article <1991May13.170952.1@vf.jsc.nasa.gov> kent@vf.jsc.nasa.gov writes: >The only think I see in your calculations is: > >You state the odds of all four vehicles surviving. What is the odds of one >vehicle surviving 80 flights? > The odds of one shuttle surviving 80 flights is (assuming 97.5% reliability) 6.58:1 against. E.g there is a 86.8% chance that a shuttle will be lost before its 80th flight. Frank Crary UC Berkeley