Space shuttle for space tourism and first stage of a TSTO.
in [Physics]
|
Prev: Eclipses Yield First Images of Elusive Iron Line in Solar Corona
Next: What happens when all dimensions are doubled overnight?
From: Jeff Findley on 14 Jan 2010 13:59 "Androcles" <Headmaster(a)Hogwarts.physics_r> wrote in message news:fMp3n.6$qF1.3(a)newsfe11.ams2... > > "Derek Lyons" <fairwater(a)gmail.com> wrote in message > news:4b502501.43877375(a)news.supernews.com... >> Robert Clark <rgregoryclark(a)yahoo.com> wrote: >> >>>The ET tank is larger than the shuttle orbiter. My proposal would be >>>to fit a much smaller tank, both in dimensions and mass, inside the >>>payload bay. >> >> Which gains you about 10 seconds, at best, of SSME burn time. >> >> D. >> -- >> Touch-twice life. Eat. Drink. Laugh. >> >> http://derekl1963.livejournal.com/ >> >> -Resolved: To be more temperate in my postings. >> Oct 5th, 2004 JDL > > Hmm... enough to send a LEM and a command module > out of Earth orbit and on their way to the Moon... and the > CM back again. > -- Laugh now, eat later. Absolutely wrong. Look at the size of the third stage of the Saturn V which performed the TLI burn for the Apollo lunar missions. Here's a hint, it's far too large to fit in the shuttle payload bay. If you don't believe this, do the math and post the result here. Several readers of this group are qualified to check your math. Jeff -- "Take heart amid the deepening gloom that your dog is finally getting enough cheese" - Deteriorata - National Lampoon
From: Derek Lyons on 14 Jan 2010 14:37 David Spain <nospam(a)127.0.0.1> wrote: >On 1/13/2010 2:55 PM, Derek Lyons wrote: >> Robert Clark<rgregoryclark(a)yahoo.com> wrote: >> >>> The ET tank is larger than the shuttle orbiter. My proposal would be >>> to fit a much smaller tank, both in dimensions and mass, inside the >>> payload bay. >> >> Which gains you about 10 seconds, at best, of SSME burn time. >> >> D. > >Derek, > >Bob Clark wants to replace the SSME's with Russian NK-33's burning LOX/Kerosene. To which the answer is the same: A fuel tank in the cargo bay gains you 10 seconds, at best, of NK-33 burn time. D. -- Touch-twice life. Eat. Drink. Laugh. http://derekl1963.livejournal.com/ -Resolved: To be more temperate in my postings. Oct 5th, 2004 JDL
From: Robert Clark on 14 Jan 2010 16:46 On Jan 14, 2:37 pm, fairwa...(a)gmail.com (Derek Lyons) wrote: > David Spain <nos...(a)127.0.0.1> wrote: > >On 1/13/2010 2:55 PM, Derek Lyons wrote: > >> Robert Clark<rgregorycl...(a)yahoo.com> wrote: > > >>> The ET tank is larger than the shuttle orbiter. My proposal would be > >>> to fit a much smaller tank, both in dimensions and mass, inside the > >>> payload bay. > > >> Which gains you about 10 seconds, at best, of SSME burn time. > > >> D. > > >Derek, > > >Bob Clark wants to replace the SSME's with Russian NK-33's burning LOX/Kerosene. > > To which the answer is the same: A fuel tank in the cargo bay gains > you 10 seconds, at best, of NK-33 burn time. > > D. > -- Perhaps you are assuming you use just the maximum of 25,000 kg shuttle payload mass allowed under the current shuttle system. I'm taking the full payload bay volume of about 300 cubic meters and filling it with propellant. This would give about 300,000 kg of lox/ kerosene, or about 100,000 kg lox/LH2 if you wanted to use the same idea but keep the SSME's. It will require strengthening of the orbiter midfuselage, but I'm arguing the extra structural mass would be less than the structural mass already needed on the shuttle to hold the 500,000 kg or so of propellant remaining in the ET after SRB sep. Bob Clark
From: Androcles on 14 Jan 2010 17:12 "Jeff Findley" <jeff.findley(a)ugs.nojunk.com> wrote in message news:5f92$4b4f6999$927a2cda$8562(a)FUSE.NET... > > "Androcles" <Headmaster(a)Hogwarts.physics_r> wrote in message > news:fMp3n.6$qF1.3(a)newsfe11.ams2... >> >> "Derek Lyons" <fairwater(a)gmail.com> wrote in message >> news:4b502501.43877375(a)news.supernews.com... >>> Robert Clark <rgregoryclark(a)yahoo.com> wrote: >>> >>>>The ET tank is larger than the shuttle orbiter. My proposal would be >>>>to fit a much smaller tank, both in dimensions and mass, inside the >>>>payload bay. >>> >>> Which gains you about 10 seconds, at best, of SSME burn time. >>> >>> D. >>> -- >>> Touch-twice life. Eat. Drink. Laugh. >>> >>> http://derekl1963.livejournal.com/ >>> >>> -Resolved: To be more temperate in my postings. >>> Oct 5th, 2004 JDL >> >> Hmm... enough to send a LEM and a command module >> out of Earth orbit and on their way to the Moon... and the >> CM back again. >> -- Laugh now, eat later. > > Absolutely wrong. > > Look at the size of the third stage of the Saturn V which performed the > TLI burn for the Apollo lunar missions. Here's a hint, it's far too large > to fit in the shuttle payload bay. > > If you don't believe this, do the math and post the result here. Several > readers of this group are qualified to check your math. > > Jeff > -- > "Take heart amid the deepening gloom > that your dog is finally getting enough cheese" - Deteriorata - National > Lampoon The 25 tons payload capacity would result in just 30 seconds longer burn time. You could of course fit up to 79 tons of fuel into the bay by volume for a 90 second burn time if the shuttle were structurally designed for it. http://answers.yahoo.com/question/index?qid=20091008092219AAb4Ce7 I suppose 90 seconds is about 10 seconds the same way a 6 foot tall man is about 2 feet tall. If you don't believe this, do the math and post the result here. Several readers of this group are not qualified to check your math. "Take heart the deepening rocket's red glare is finally bursting in air, but you don't HAVE to swallow bullshit" -- Androcles.
From: Robert Clark on 14 Jan 2010 17:22
On Jan 14, 4:46 pm, Robert Clark <rgregorycl...(a)yahoo.com> wrote: > ... > Perhaps you are assuming you use just the maximum of 25,000 kg > shuttle payload mass allowed under the current shuttle system. > I'm taking the full payload bay volume of about 300 cubic meters and > filling it with propellant. This would give about 300,000 kg of lox/ > kerosene, or about 100,000 kg lox/LH2 if you wanted to use the same > idea but keep the SSME's. > It will require strengthening of the orbiter midfuselage, but I'm > arguing the extra structural mass would be less than the structural > mass already needed on the shuttle to hold the 500,000 kg or so of > propellant remaining in the ET after SRB sep. > Remember a large mass of propellant carried on the *inside* is the usual way rockets operate. Think of it this way: which would require greater mass and complexity of structural strengthening members, the S-IC Saturn V first stage carrying the 5,000,000 lbs. of propellant inside, as it actually did, or a huge outside tank hanging off attachments points containing, say, 8,000,000 lbs, with just a big empty space in the rocket between the engines and the second stage? Cutaway diagram of the S-IC http://upload.wikimedia.org/wikipedia/commons/d/de/SaturnV_S-IC.jpg Bob Clark |