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Glom
2005-Aug-09, 07:04 PM
The modified 742 will be used to ferry Discovery back to Complex 39. Not realising this, someone asked at another forum if the orbiter would takeoff from Edwards and fly like a regular aircraft to Kennedy.

Of course, we all know that there is no tankage in the orbiter itself for the SSMEs so this is not an option. However, I was wondering if there was some massive technical reason why the orbiter couldn't have been designed to have a tank placed in the payload bay to feed the main engines. I know that of course the orbiter design doesn't include any ability to feed propellents to the SSMEs from any tank in the payload bay, but suppose such umbilicals were incorporated.

It could perhaps be logistically easier to do this than having to get a 742 to Edwards, load the orbiter onto its back and then transport it back with the requisite refuelling. Some of the huge Space Shuttle fixed program costs could go down a bit if the thing was more flexible and convenient like this.

Of course, this depends on the following factors:
The payload bay being capable of containing sufficient propellents.
The transport of a suitable tank with propellents by logistically simple compared to the 742.It would be cool.

skrap1r0n
2005-Aug-09, 07:09 PM
Not realising this, someone asked at another forum if the orbiter would takeoff from Edwards and fly like a regular aircraft to Kennedy.

are you kidding?

Glom
2005-Aug-09, 08:18 PM
I just thought of a show stopper for this: the fact that the Space Shuttle isn't reusable but merely repairable. The SSMEs virtually destroy themselves on launch.

formulaterp
2005-Aug-09, 08:35 PM
Well, the first problem you identified is enough of a showstopper. The STS external tank has somewhere in the range of 72,500 cubic feet of tankage for the H2 and LOX propellant. Even if the entire orbiter's cargo bay were utilized, you only have about 10,600 cubic feet to play with. A rough calculation indicates that the SSME's would use up this fuel in a little over a minute. Might be enough to take off, but you'd be landing pretty darn quick.

Also I believe that the 747 transport aircraft is already based in California, so no need to send it over there.

Glom
2005-Aug-09, 08:41 PM
But the SSME's wouldn't have to operate at full thrust.

Can someone provide a credible reference to the rebuilding required of the SSMEs following a mission? Someone is grilling me for one at airliners.net.

Saluki
2005-Aug-09, 09:25 PM
Aside from the other issues mentioned, using rocket propulsion for aerodynamic flight is pretty wasteful. It is ok for somethign small like a guided missile, but for something the size of the space shuttle, it is simply not practical. If you could figure out a way to strap big jet engines on it, you might be able to get it to fly, but that would be an engineering nightmare all of its own.

Ara Pacis
2005-Aug-09, 09:42 PM
The replacement vehicle I designed in the back of an envelope carries both rocket engines for space and jet engines for atmosphere and retractable wings is still 1/4 the size of the STS orbiter and probably less than 1/4 the mass. I think the only real alternative to flying the Orbiter piggy-back on a 747 is to ship it through the Panama Canal. I don't think that any highways or railroads could accommodate something that big cross country.

Glom
2005-Aug-09, 09:44 PM
The replacement vehicle I designed in the back of an envelope carries both rocket engines for space and jet engines for atmosphere and retractable wings is still 1/4 the size of the STS orbiter and probably less than 1/4 the mass.

Why retractable wings? Retractability only adds weight.

Remember that volume scale factor is the cube of linear scale factor.

Robert Andersson
2005-Aug-09, 09:46 PM
I'm no expert, and I haven't checked it, but a few additional issues come to mind:

* The shuttle is a glider. Its aerodynamic properties doesn't allow it to fly as a normal airplane, unless they strap on an extra pair of wings. A guess is that it would need insanely high velocity (and thus runway) to take off.

* I don't think the engines are designed to allow "variable" thrust as would be required in a normal flight.

* It is very inefficient not using air breathing propulsion while in the atmosphere.

Glom
2005-Aug-09, 09:51 PM
* The shuttle is a glider. Its aerodynamic properties doesn't allow it to fly as a normal airplane, unless they strap on an extra pair of wings. A guess is that it would need insanely high velocity (and thus runway) to take off.

Glider + thrust = aeroplane


* I don't think the engines are designed to allow "variable" thrust as would be required in a normal flight.

I believe they are because otherwise the Gs would kill the crew at the end of the burn if not for the throttling down.


* It is very inefficient not using air breathing propulsion while in the atmosphere.

In that case, Lockheed won't sell any to Southwest Airlines.

Robert Andersson
2005-Aug-09, 10:22 PM
Glider + thrust = aeroplane
Yes, but it has very poor lift in low speeds. It It would probably need mach 1-2 just to keep itself in the air. Some tricks with vector thrusting and steep angle of attack might allow it to fly at lower speeds.


* I don't think the engines are designed to allow "variable" thrust as would be required in a normal flight.
I believe they are because otherwise the Gs would kill the crew at the end of the burn if not for the throttling down.
Yeah, I know, but I sceptical if they allow throttling as "normal" engine, as would be needed when changing course etc.



* It is very inefficient not using air breathing propulsion while in the atmosphere.
In that case, Lockheed won't sell any to Southwest Airlines.
I'm not following you here :-?

Sorry for the bad answers; I would research but I really need to go to bed soon.

Argos
2005-Aug-09, 10:39 PM
Glider + thrust = aeroplane
Yes, but it has very poor lift in low speeds. It It would probably need mach 1-2 just to keep itself in the air. Some tricks with vector thrusting and steep angle of attack might allow it to fly at lower speeds.

Why not rotor blades? :lol:

just kidding

Ara Pacis
2005-Aug-09, 10:51 PM
The replacement vehicle I designed in the back of an envelope carries both rocket engines for space and jet engines for atmosphere and retractable wings is still 1/4 the size of the STS orbiter and probably less than 1/4 the mass.

Why retractable wings? Retractability only adds weight.

Remember that volume scale factor is the cube of linear scale factor.

I was considering two designs. One is a dart shape with a long thin delta wing, almost a lifting body integration, that stays within the hypersonic compression wave during a shuttle-type re-entry and uses a pair of wings that rotate out to a sweep of 30 degrees in order to make the vehicle capable of powered atmospheric flight at lower altitudes and velocities (think F-14). The second design might use a hinged rogallo wing and act as a wave-rider during reentry but it may need to have a variable wingspan in order to be capable of powered atmospheric flight at lower altitudes and velocities. but I am not an aeronautical engineer, I'm a synthesist who tries to make new ideas by combining several. Maybe these ideas would work, maybe not.

formulaterp
2005-Aug-09, 10:55 PM
It's a pointless exercise, but anyway ... :D

The SSME's can be throttled from 65-109% power. For most of the flight they operate at near full power, adjusting occasionally to reduce g-loading on the crew. They throttle back to their minimum limits just a few moments before shutdown.

The shuttle expends all of the ET's stored fuel in just 8.5 minutes. Even at minimum thrust, how long do you suppose a cargo bay's worth of fuel will last? 2-3 minutes? Even if you could somehow accelerate to orbital velocity (which you can't !!!) the flight time from Edwards to KSC is nearly 10 minutes.

The orbiter's gliding characteristics are horrible. Perhaps the worst of any operating aircraft in the world today. I don't know the exact term but the "lift/drag ratio" is something like 1:1, in comparison most aircraft are in the 10-20:1 ballpark, while gliders are 50:1 or better.

The Russian version of the Shuttle (Buran) had a prototype model built with jet engines. It was never intended for production usage, but rather to test it's flight characteristics, much like how NASA used the (unpowered) Enterprise. There's very little info about it, so I don't know if the Buran analogue ever took off from a runway, or was air-launched and used it's turbofans just for landing.

Extravoice
2005-Aug-09, 11:17 PM
Forget flying, Discovery has wheels and should be able to drive to Florida. :)

If it can't, I want a refund on that Eisenhower Interstate highway system.

Donnie B.
2005-Aug-10, 12:00 AM
Glider + thrust = aeroplane
Yes, but it has very poor lift in low speeds. It It would probably need mach 1-2 just to keep itself in the air. Some tricks with vector thrusting and steep angle of attack might allow it to fly at lower speeds.

Why not rotor blades? :lol:

just kidding
Shuttle + chopper = shupple ?

Maybe a big rotating wing - world's biggest gyrocopter... 8)

Nergal
2005-Aug-10, 12:10 PM
* The shuttle is a glider. Its aerodynamic properties doesn't allow it to fly as a normal airplane, unless they strap on an extra pair of wings. A guess is that it would need insanely high velocity (and thus runway) to take off.

Glider + thrust = aeroplane
True, but not applicable in this case.

The Shuttle is designed not so much to be a glider, but to maintain a controlable fall. It's a remarkably poor lifting body. I couldn't find any specifics via google (at least not in an admittly brief search), but I'd guess the Shuttle would need to reach an absurdly impracticle speed to generate enough lift to take off or even maintain flight.

Then there's the problem of on-board fuel...

NEOWatcher
2005-Aug-10, 12:30 PM
(wasn't there an early design with jets for assisted landings? or am I just thinking Buran?)
Design aside, what about risk? The 747 is a much easier craft to control.
And, for what you saved in transportation, you would probably add to maintenance for the added complexity.

Swift
2005-Aug-10, 01:48 PM
<snip>
The orbiter's gliding characteristics are horrible. Perhaps the worst of any operating aircraft in the world today. I don't know the exact term but the "lift/drag ratio" is something like 1:1, in comparison most aircraft are in the 10-20:1 ballpark, while gliders are 50:1 or better.

As Monty Python said about flying sheep in trees, "They don't so much fly as they do plummet". :D

kucharek
2005-Aug-10, 01:54 PM
The orbiter's gliding characteristics are horrible. Perhaps the worst of any operating aircraft in the world today. I don't know the exact term but the "lift/drag ratio" is something like 1:1, in comparison most aircraft are in the 10-20:1 ballpark, while gliders are 50:1 or better.
The orbiter's lift/drag ratio is around 4. Better than most bricks. But - it's a spaceship. I don't know if we could built 747-like wings which could survive a re-entry. Would also be much too heavy. As I said, we want a spacecraft, not a glider.

Ara Pacis
2005-Aug-10, 05:41 PM
That reminds me. I think it was in regards to the F-104's aerodynamics that one person said "It proves that, given a large enough engine, even a brick will fly."

publiusr
2005-Aug-10, 08:59 PM
Very true--and without fly-by wire--even the conventional looking F-16 cannot fly.

A Buran analogue was capable of some self-ferry.
http://www.astronautix.com/craft/burlogue.htm

http://www.k26.com/buran/Future/OK-GLI/aero_tester_ok-gli__bst-2_.html

http://www.k26.com/buran/Future/energia_-_buran_-_where_are_th.html

Nicolas
2005-Aug-10, 09:24 PM
That reminds me. I think it was in regards to the F-104's aerodynamics that one person said "It proves that, given a large enough engine, even a brick will fly."

That was the F-4 Phantom or "flying brick".
link (http://www.craigcentral.com/models/f-4e/default.asp)
http://www.aerospaceweb.org/aircraft/fighter/f4/f4_09.jpg

Or it's Russian counterpart: the MiG 25 Foxbat

http://combatavia.com1.ru/mig25_9.jpg

The F-104 "starfighter" was called "the flying rocket" due to it's tiny wings.


the F-16 is very well capable of generating enough lift, though it is an unstable design which needs a flight computer to keep it stable - but makes it very maneuvrable.

publiusr
2005-Aug-10, 09:30 PM
I love that MiG 25 photo. With it you fly about half as high, and 70% as fast as SS1--and for less money.

I also remember on program relating how an F-4 was left behind by the Foxbat it was following. Didn't the Foxbat get the altitude record away from the NF-104 Yeager flew?

Nicolas
2005-Aug-10, 09:40 PM
Space Adventures does do "edge of space" flights with it. You get high enough to see the atmosphere getting darker and a bit of the curvature of the earth.

The Supreme Canuck
2005-Aug-10, 10:10 PM
Hey, uh, guys? Why are we bothering to talk about a space shuttle that can fly itself where it wants to go? Why not just land it where you want it? I mean, the thing is already in orbit. Just glide to the proper place. Sure, you may need it at a facility other than KSC, but wouldn't it be easier to move the facility than to design a new shuttle (or modify existing ones) for powered atmospheric flight?

madamwitty
2005-Aug-11, 01:59 PM
I couldn't find any specifics via google (at least not in an admittly brief search), but I'd guess the Shuttle would need to reach an absurdly impracticle speed to generate enough lift to take off or even maintain flight.

Yeah, I couldn't find much either. I found a few documents on the NASA Technical Reports Server (http://ntrs.nasa.gov/), but I'd have to order them from NASA since they don't have it the ones I'd want in electronic format, and I'm too impatient for that... :)

publiusr
2005-Aug-11, 06:03 PM
Hey, uh, guys? Why are we bothering to talk about a space shuttle that can fly itself where it wants to go? Why not just land it where you want it? I mean, the thing is already in orbit. Just glide to the proper place. Sure, you may need it at a facility other than KSC, but wouldn't it be easier to move the facility than to design a new shuttle (or modify existing ones) for powered atmospheric flight?

It takes a lot to mount the orbiters atop the 747 carrier--more of the 'standing army' deal. A buran like craft is not that hard a build. Remember--the big hydrogen engines go under the ET--and the only rockets are the kero/lox thrusters the equivalent of our OMS. This is a Rutan scale project in that the thrusters and the jets are around his scale of construction.

A "Rutan Buran" would be perfect for him. NASA builds an Energiya type HLLV for VSE, and Rutan builds that but with a better heat shield.

So you keep the rocket people and airplane people out of each others hair. With self-ferry jets, you could land most anywhere and not have delays with dead-stick gliders that have to have everything just so.

Such a self-propelled Buran type craft would also be turned around so much more quickly.

The Supreme Canuck
2005-Aug-11, 06:24 PM
Sure, but why not just have everything you need to launch right where you land the thing? No need to ferry it at all.

Argos
2005-Aug-11, 06:29 PM
I donīt think you could launch from Edwards (safety reasons).

Edited.

The Supreme Canuck
2005-Aug-11, 06:32 PM
So land at KSC.

publiusr
2005-Aug-11, 06:33 PM
That may not always be possible. Storms, Hurricanes, etc. Self -ferry also makes the orbiter more usable and opens up a lot more abort profiles in case of medical emergencies.

The Supreme Canuck
2005-Aug-11, 06:36 PM
I suppose that's true. The first problem can be overcome by having backup landing strips and a transport plane ready to be used. Pretty much like now, but with less use for the plane.

The second problem, though, is a pretty valid point. But would it be worth the increased weight? Carrying around jet engines and jet fuel that would likely not be used seems to be a waste to me. If they could find a way to use the main engines, it could be viable, though unlikely.

Argos
2005-Aug-11, 07:29 PM
A propos:

http://www.spacedaily.com/news/shuttle-03o2.html

"NASA is already considering landing all future Shuttles at Edward Air Force Base in California, rather than landing them directly at Cape Canaveral, to minimize the impact of any future Shuttle crashing.

Although this will increase its operating costs still further. It is considered to be a minor miracle that no one in Texas was injured by any of falling debris"

The Supreme Canuck
2005-Aug-11, 07:56 PM
Hm. Didn't think of that. I was just thinking of when things work properly. So, scratch that idea. :-?

Nergal
2005-Aug-12, 02:41 PM
The second problem, though, is a pretty valid point. But would it be worth the increased weight? Carrying around jet engines and jet fuel that would likely not be used seems to be a waste to me. If they could find a way to use the main engines, it could be viable, though unlikely.
Well, I think that if we decide it's of some benefit to have a shuttle with powered atmospheric flight, then the next obvious question would be, "Do we need a shuttle as big as the current one?"

If we were willing to use HLVs to toss heavy cargo into orbit, and the shuttle only as a crew/service vehicle...would it be feasible to reduce the size, do away with the huge cargo bay (or most of it)? Basically change the shuttle from space-truck to space-sedan.

publiusr
2005-Aug-12, 06:50 PM
I think that is reasonable--but I want a wide wingspan to reduce wing loading--a metal heat-shield, etc. Fuel cells will add water to the jets--and help keep them warm in space.

Dream chaser looks fine--and a recent Popular Science article in 2002 had an early quiet supersonic platform design that has vanished from the web. It had a shuttle type wing--Churchill (Lifeforce) type canards--and the intakes were on top--to focus the sonic boom upward.

The underside was very flat--so that helps with the heatshield.


It looks like the Air Force is in trouble again
http://www.cnn.com/2005/US/08/10/car.vandalism.ap/index.html
http://www.xprizenews.org/index.php?p=1059

Future concepts for winged flight
http://www.globalsecurity.org/military/systems/aircraft/b-3_gallery.htm

publiusr
2005-Aug-17, 08:44 PM
Here is a similar self transporting Buran like craft:
Back to Heavy Lift--here are some interesting links:

http://www.buran.ru/htm/ok-92.htm
Updated!
http://www.buran.ru/htm/history.htm

Misc.
http://www.buran.ru/images/jpg/mtkkman2.jpg
http://www.buran.ru/htm/rocket.htm
http://www.buran.ru/htm/rocrt.htm
http://www.buran.ru/htm/compare.htm
http://www.buran.ru/htm/shutlkpr.htm

cockpit:
http://www.buran.ru/htm/soi.htm

energia-2 :
http://www.buran.ru/htm/41-3.htm

publiusr
2005-Aug-19, 07:55 PM
yet more:
http://www.nasawatch.com/archives/2005/08/cev_launcher_tr.html
http://www.space.com/news/050810_dod_launcher.html
http://www.space.com/businesstechnology/050803_shuttle-derived_cev.html

More Buran pics--self transport Buran?
http://es.wikipedia.org/wiki/Transbordador_Buran#El_Shuttle

http://makeashorterlink.com/?O264135AB


http://www.espacial.org/astronautica/vuelotripulado/buran5.htm
http://www.espacial.org/astronautica/vuelotripulado/buran.htm
http://www.espacial.org/astronautica/vuelotripulado/buran3.htm
http://www.espacial.org/astronautica/vuelotripulado/buran6.htm

Nice links:
http://www.space.com/businesstechnology/050810_mars_homestead.html


Iran has solids
http://www.spacewar.com/news/iran-05zm.html

Solar Sails! http://www.spacedaily.com/news/solarsails-05l.html

Superhard Ceramics
http://www.spacedaily.com/news/materials-05zj.html


Dust Devils
http://www.spacedaily.com/yesterday/spacedaily-2005-08-12.html

Name that Planet:
http://www.spacedaily.com/2005/050802153054.3eb77bsx.html
Asteroid hit:
http://www.spacedaily.com/news/early-earth-05h.html