Space shuttle for space tourism and first stage of a TSTO.
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From: Pat Flannery on 6 Jan 2010 13:27 Jeff Findley wrote: > "Pat Flannery" <flanner(a)daktel.com> wrote in message > news:X_GdnUlUu5jmutnWnZ2dnUVZ_uidnZ2d(a)posted.northdakotatelephone... >> I can't for the life of me figure out why Robert Clark is constantly >> coming up with ideas for so radically modifying something that already >> exists that it effectively becomes a entirely different spacecraft, but >> without the advantages that a whole new design would offer. > > I don't know, but I solved the problem long ago by putting him in my > killfile. But I like reading up on what's going to get modified next. You know...it would be possible to take the Queen Mary II and turn it into a submarine at fairly low cost...all we have to do is drill a lot of holes in the bottom of the hull, and then... :-) Pat
From: Pat Flannery on 6 Jan 2010 13:34 Me wrote: > Clark, face it, you don't know what you are talking about and your > ideas are not workable. You know, it would be possible to convert a 747 into a earth-boring machine at fairly low cost also. All we have to do is make the wings jettisonable...add a LOX-kerosene rocket engine to its tail... Pat
From: Jonathan on 6 Jan 2010 21:37 "Robert Clark" <rgregoryclark(a)yahoo.com> wrote in message news:411e6624-7064-46ff-a84e-5df026de917e(a)o28g2000yqh.googlegroups.com... > This article describes the plan to sell the orbiters minus engines > for $42 million: > > For sale: Used space shuttles. Asking price: $42 million apiece Hmm, could a business be built around using an orbiter as a tourist attraction? Use it like a simulator and sell 'stick time' to wannabe astronauts and rich kids alike? Make a hellova billboard having an orbiter sitting out front for all to see. I bet the Smithsonian gets one of them, another ends up in someplace weird like Abu Dhabi, and the third goes to some rich nutjob that just has to have one to impress his friends. > By John Matson > Dec 18, 2008 04:00 PM in Space > http://www.scientificamerican.com/blog/post.cfm?id=for-sale-used-space-shuttles-asking-2008-12-18 > > It is currently intended only to be sold to educational institutions, > or governmental agencies. > The Air Force is looking for designs for reusable first stage > boosters for two-stage-to-orbit (TSTO) systems. Then it might be able > to be used for this purpose. Most likely you would use kerosene fuel > for this since dense fuels are more suitable for first stages. > The payload bay would be converted to a fuel tank, and the second > stage of the TSTO would be carried on top or below the orbiter. High > performance kerosene engines such as the Russian NK-33, with a near > legendary thrust/weight ratio of 136.66 to 1 at a weight of 1,222 kg, > could be used for propulsion: > > NK-33. > http://www.astronautix.com/engines/nk33.htm > > The orbiter without the SSME engines masses around 68,600 kg: > > Atlantis. > http://www.astronautix.com/craft/atlantis.htm > > Its payload bay is around 300 cubic meters that could be used for > propellant. Using the densities of kerosene and lox given here: > > Lox/Kerosene. > http://www.astronautix.com/props/loxosene.htm > > and the oxidizer to fuel ratio of the NK-33 of 2.8 to 1 we can > calculate the propellant load that can be carried as about 300,000 kg. > You would need at least 3 of the NK-33's to lift this fuel load, > orbiter and second stage. > The tank weight of kerosene/lox is typically around 1/100th of the > propellant weight so around, 3,000 kg. Then the empty weight of the > reconfigured orbiter would be 68,600kg + 3*1,222kg + 3,000kg = > 75,266kg. And the fully fueled weight of this stage would be > 375,266kg. > For this first stage alone without a second stage, this would be a > mass ratio of about 5. Using an average Isp of the NK-33 of 315 you > could get a delta-V of 315*9.8*ln(5) = 4,970 m/s, about Mach 15. > A total delta-V this high raises the possibility it could be used for > suborbital space tourism or point-to-point hypersonic transport, if > sale to commercial organizations were to be allowed. > > > Bob Clark >
From: trigonometry1972 on 7 Jan 2010 01:58 On Jan 6, 12:49 am, Pat Flannery <flan...(a)daktel.com> wrote: > David Spain wrote: > >> As far as a hypersonic transport you'd need > 3 orbiters or a crew > >> compartment capable of flying > 7 people, unless they're riding in > >> a can atop the thing. > > > Oops, I meant *next to* the thing... > > Now picture a SR-71...now picture a SR-71 with a SRB strapped to its > back, a big LOX tank attached under either of its engine nacelles, and a > SSME converted to LOX/JP-7 in its tail...now picture that riding on a > giant take-off trolley, with a trained Chimpanzee in the cockpit...but > not just any Chimpanzee...a Chimpanzee that has been genetically > modified with Bald Eagle DNA to give it an intuitive ability to > understand flight... ;-) > > Pat Hmm......."no damned filthy human DNA"......I can see it now. Better yet use a trained speciality version of a Gamma rated human. Mixing my science fiction authors....................Trig
From: Robert Clark on 7 Jan 2010 02:07
On Jan 6, 8:56 am, Robert Clark <rgregorycl...(a)yahoo.com> wrote: > ... > Moreover, it could also serve as the reusable first stage of a TSTO. > I'm arguing it could be used to reduce the costs to space if used as a > reusable first stage booster for a TSTO system. The Air Force for > instance believes such a TSTO could cut launch costs by 50%. > The Russian engines that would need to be added would be relatively > low cost. According to this page, in the mid 90's Aerojet purchased 36 > of them from the Russians for only $1.1 million each(!): > > NK-33.http://en.wikipedia.org/wiki/NK-33#History > > Installation of the lox/kerosene tanks and modifications to > strengthen the body frame to carry the extra loads would also be > relatively low cost. > The 68,600 kg empty weight of the orbiter sans engines could probably > be reduced also. The main system that could probably be removed would > be the Orbital Maneuvering System (OMS). This is used for final > orbital insertion of the shuttle and changes of its orbit. This > wouldn't be needed for a first stage vehicle or a suborbital vehicle. > I don't trust the value given for the OMS weight however on the > Atlantis Astronautix page. It says this: > > Main Engine: OME. Main Engine: 14,912 kg (32,875 lb). Main Engine > Thrust: 53.367 kN (11,997 lbf). Main Engine Propellants: N2O4/MMH. > Main Engine Propellants: 12,412 kg (27,363 lb). Main Engine Isp: 316 > sec. Spacecraft delta v: 700 m/s (2,290 ft/sec). > > The OME refers to the OMS engine. The engine does not weigh 14,912 > kg. Perhaps they are referring to the entire OMS system, both pods. > That seems unlikely as well, unless they are including the propellant > weight. > In any case it's this OMS system weight that I'm trying to find out > to subtract off. > Used alone without a second stage it could achieve high hypersonic speeds. The hypersonic, subsonic, and reentry characteristics of the orbiter are well understood. Once used as a first stage, it might lead trade studies to be done to see if a vehicle of similar dimensions but made of all composite construction could have a significantly better mass ratio. Could it even reach orbit? I would like to see a breakdown of the orbiter subsystem weights to see which ones could be removed for this application, and which ones such as the frame and body panels could be replaced with lightweight composites, if anyone knows a reliable source for this. The Astronautix page on the Atlantis gives some subsystem weights including the airframe structural weight but their numbers can be unreliable. As a first guess, I'm thinking that going to an all-composite version of the shuttle with propellant tanks in the payload bay would not allow this reconfigured shuttle to reach orbit. However, there is a significant amount volume in the wings, at about a 250 square meter wing area and maximum wing thickness of 1.5 meters. This could amount to a propellant tank volume near that of the payload bay. Note that for aircraft it is common to hold the fuel in the wings. The shuttle wings would need significant strengthening to hold this higher weight however. This would add on to the dry weight. However, again as a first guess, use of this wing volume on an all-composite version would give you a vehicle that could reach orbit. Then you would have a fully reusable SSTO. Bob Clark |