F-14 Space Launch Vehicle

Well it looks like there is another remarkable role the greatest plane(at least the best looking imo)ever built was capable of filling.

F-14 Space launcer

To bad, the Navy always wanted to have its own space launch capability. Didn't realize it was sitting right in front of them.

That seems a bit mental to me, almost as mental as trying to turn a Learjet into a spaceship, but someones trying that too!

Originally posted by danwild6
Well it looks like there is another remarkable role the greatest plane(at least the best looking imo)ever built was capable of filling.

F-14 Space launcer

To bad, the Navy always wanted to have its own space launch capability. Didn't realize it was sitting right in front of them.

Why not think bigger and convert a 747 jumbo to a space shuttle?

it would take of horizontally then go vertical near space...


the air breathing jet engines would be supplied from on board oxygen near about 60000 feet as the atmosphere thins out..

just think of the payload you could carry...

what do you think?

any technical problems?

Originally posted by esecallum
Why not think bigger and convert a 747 jumbo to a space shuttle? it would take of horizontally then go vertical near space... the air breathing jet engines would be supplied from on board oxygen near about 60000 feet as the atmosphere thins out..

I think you may have misunderstood the concept (or i've misunderstood your post). The proposed idea in the link isn't to get the F-14 into space, it's just meant to carry the rocket underneath it up to a certain height and then let it go from there. Like how the White Knight/SpaceShipOne works basically.

I don't think it would be possible to attach something underneath a 747, not without some serious modification (correct me if i'm wrong on that). You could attach something above in a similar fashion to the 747 that transports the shuttle, but launching something from on top is a lot more risky and dangerous and generally just not a good idea overall.

From the pictures on the website danwild6 linked to, it seems that there might be some issues with the F-14's landing gear during takeoff. It looks like there is a big space between the nose of the rocket and they payload area to accomodate the F-14's nose gear - but then it looks like there's a big tank of kerosene in the nose, too. It would probably be easier to rig up some sort of wheeled carriage to support the nose of the F-14/rocket combo until just after takeoff, then jettison the carriage once airborn, but that hardly seems ideal, either...

In any case, it will be a tough job to make this setup more economical than the similar-in-concept Pegasus launch vehicle. Granted, the L-1011 used by Orbital for Pegasus launches is traveling at ~40,000 feet and signficantly less than Mach 1 when the Pegasus is launched - lower and slower than a conceptual F-14 launched rocket - but I'm not convinced that using an F-14 as a carrier aircraft is the best way to go.

There has to be a pretty goodly amount of drag on the F-14 carrying an underslung rocket, and what does carrying that size and shape of payload do to the handling qualities, trans-sonic/supersonic performance, and fuel economy of the F-14? Another potential problem is that - unless I disremember - the F-14 is a pretty maintainance-heavy airplane. It sounds like they're considering making custom modifications to an aircraft that already requires a lot of maintainance, and I'm not sure that's the best idea in the history of rocket science...

This has been discussed on ATS before..

Originally posted by jra

Originally posted by esecallum
Why not think bigger and convert a 747 jumbo to a space shuttle? it would take of horizontally then go vertical near space... the air breathing jet engines would be supplied from on board oxygen near about 60000 feet as the atmosphere thins out..

I think you may have misunderstood the concept (or i've misunderstood your post). The proposed idea in the link isn't to get the F-14 into space, it's just meant to carry the rocket underneath it up to a certain height and then let it go from there. Like how the White Knight/SpaceShipOne works basically.

I don't think it would be possible to attach something underneath a 747, not without some serious modification (correct me if i'm wrong on that). You could attach something above in a similar fashion to the 747 that transports the shuttle, but launching something from on top is a lot more risky and dangerous and generally just not a good idea overall.

my idea is to get the 747 into space
WITHOUT external additions.

the 4 engines would be modified to provide much higher thrust such that they can support net acceleration upwards when clearing the atmosphere and when the plane is vertical and not using wings anymore as it nears outer space...

remember a 747 can last 10 hours or more on a flight inside the atmosphere..

thus the thrust or acceleration upwards does not have to be huge like a saturn 5 rocket etc....

a normal rocket must provide huge thrust and be able to accelerate the rocket upto 7 to 11 km/sex within 5 to 10 minutes and use all that fuel up.


a smaller thrust or acceleration upwards for LONGER time will achieve orbit also.

thus we should focus on modyfying a 747 instead of f-14 or learjets as they are too small and lack ambition.

Originally posted by esecallum
thus the thrust or acceleration upwards does not have to be huge like a saturn 5 rocket etc.... a normal rocket must provide huge thrust and be able to accelerate the rocket upto 7 to 11 km/sex within 5 to 10 minutes and use all that fuel up. a smaller thrust or acceleration upwards for LONGER time will achieve orbit also. thus we should focus on modyfying a 747 instead of f-14 or learjets as they are too small and lack ambition.

You need to be traveling at least 7800 m/s if you want to maintain a low Earth orbit. That won't happen if you aren't traveling fast enough.

I don't think it would be possible to convert a 747 to go into orbit. One of many large issues would be the heat shield, or lack there of. I don't think those wings could handle the stress of re-entry either.

With all the work you'd have to do to convert it, one might as well just build something from scratch.

[edit on 15-1-2007 by jra]

Originally posted by jra

Originally posted by esecallum
thus the thrust or acceleration upwards does not have to be huge like a saturn 5 rocket etc.... a normal rocket must provide huge thrust and be able to accelerate the rocket upto 7 to 11 km/sex within 5 to 10 minutes and use all that fuel up. a smaller thrust or acceleration upwards for LONGER time will achieve orbit also. thus we should focus on modyfying a 747 instead of f-14 or learjets as they are too small and lack ambition.

You need to be traveling at least 7800 m/s if you want to maintain a low Earth orbit. That won't happen if you aren't traveling fast enough.

something from scratch.

[edit on 15-1-2007 by jra]

you are correct it must travel at 7800 m/s to MAINTAIN ORBIT.

the 747 takes of horizontally then angles upwards to 45 degrees

when it reaches about 60000 feet, oxygen is supplied to the engines from theinternal store..

as the AIR GET very THIN at above about 60000 feet the 747 would continue at a 45 degree angle this makes it gain altitude and maintain stability and becuase a 747 can burn fuel over at least 10 hours it will achieve 7800 m/s

why u ask?

because V=AT
VELOCITY = ACCELERATION X TIME

U CAN VARY A AND T IN ANY COMBINATION TO GET 7800 M/S.

lets put some figures in

5 m/s/s acceleration times 1560 seconds =7800 m/s

1560 seconds = half an hour of acceleration.

5m/s/s is 1/2 a g

g is 9.81 m/s/s which the the earts acelertion downwards...

or even at a lowly and morecomfortable 1m/s/s acceleration it will reach 7800 in 2.5 hours.


thus the 747 simply continues to gain altitude and speed..
and as the air gets thinner the higher it gets friction is not an issue....


get a pen draw a circle to represent the earth

then a larger circle to represent the atmosphere..


then draw a plane going up at 45 degrees with a line relative t the ground..


as you can see it will reach outer space and CONTINUE TO INCREASE FORWARD SPEED UPTO 7800 M/S AND CONTINUE TO GAIN ALTITUDE WHICH MEANS LEsS AND LESS FRICTION which allows it to increase speed upto 7800 or beyond...


do you see now?




as regards re-entry it will come back under engine power.

so no need for shielding.

the existing space shuttle has no fuel so it comes in at mach 25 hence the need for shielding.



as regards cost the space shttle has had over $40 billion wasted on it.

747 costs a lot less and modyfying it the cost will be nothing compared to the billions wasted on the clumsy shuttle.

any other questions?

[edit on 15-1-2007 by esecallum]

You misunderstand the principle behind air-breathing propulsion. The main reason jet engines won't work for exoatmospheric flight is that the propulsive medium they use (air) is no longer there. It is not a matter of not having anything to oxygenate the combustion reaction, but rather that the engine is not taking in any air to pump to make thrust. Even IF you could store enough compressed/liquid O2 to last a full mission (which I am highly doubtful of, given the enormous mass flow-rates of the CF6 class engines on board the 747) the engines simply won't run above 60k ft. Furthermore, the service ceiling of the 747 is in the 40k ft. area, not because of lack of O2, but because the engines no longer make enough thrust for lift to equal weight in level flight above that altitude.
All this being said, you touch on the important point many forget when considering low-cost orbital lift options. You are right that the orbital speed needn't be achieved in any given time-frame, so once you realize that it opens up a lot more options.

esecallum I think - no, I know - that you're oversimplifying the issues at hand. You can't just spray oxygen into the front end of a 747's high-bypass turbofan and expect it to run as is normal. It doesn't work like that. A Rolls-Royce concept called Skylon ran on a similar principle, but only after investing gobs of money in research and development.

Add to that the issues involved in getting a 747 to climb at a 45-degree angle for an extended period of time - even if they can do that, I doubt the airframe is designed for it - and in storing fuel and oxidizer onboard for ascent and a powered descent.

I don't think you're going to be able to modify a 747 to act as an SSTO. Sorry, but it wasn't designed for that environment.

I agree with what the previous posters have said and, If it were that easy to convert a 747 (or any plane) to fly in space, it would have been done already. Your idea sounds like it would require huge amounts of fuel, probably more than what a 747 could carry.

Originally posted by Nipples
You misunderstand the principle behind air-breathing propulsion. The main reason jet engines won't work for exoatmospheric flight is that the propulsive medium they use (air) is no longer there. It is not a matter of not having anything to oxygenate the combustion reaction, but rather that the engine is not taking in any air to pump to make thrust. Even IF you could store enough compressed/liquid O2 to last a full mission (which I am highly doubtful of, given the enormous mass flow-rates of the CF6 class engines on board the 747) the engines simply won't run above 60k ft. Furthermore, the service ceiling of the 747 is in the 40k ft. area, not because of lack of O2, but because the engines no longer make enough thrust for lift to equal weight in level flight above that altitude.
All this being said, you touch on the important point many forget when considering low-cost orbital lift options. You are right that the orbital speed needn't be achieved in any given time-frame, so once you realize that it opens up a lot more options.

ummmm...

a jet engine burns fuel mixed with atmospheric air and creates thrust
a rocket engine burns fuel mixed with onboard oxygen/air and creates thrust.

converting a air breather to an onboard oxygen breather is not an issue...
this has already been done in various experimental engine set ups and tested.

minor enginering details.


enormous flow rate of a 747 CF6??

a 747 can stay in the air easily for at least 20 hours without refueling.depending on payload.

A SATURN 5 ROCKET THROWS OUT 15 TONS OF PROPELLANT A SECOND.
NOW THAT IS ENORMOUS.

as the plane is going upwards at an 45 degree angle the wings provides most of the lift...reducing fuel consumption.

at over 40000 ft the engines take over and remember as the plane get faster and faster due to less and less drag the large 747 wings will still provide some lift.

i believe it is possible to possible to convert a 747 to a shuttle.

the reason people are opposed is the same reason every major technological idea has been opposed in recorded history.
people just dont want anyone else to succeed.

Originally posted by PhloydPhan
esecallum I think - no, I know - that you're oversimplifying the issues at hand. You can't just spray oxygen into the front end of a 747's high-bypass turbofan and expect it to run as is normal. It doesn't work like that. A Rolls-Royce concept called Skylon ran on a similar principle, but only after investing gobs of money in research and development.

Add to that the issues involved in getting a 747 to climb at a 45-degree angle for an extended period of time - even if they can do that, I doubt the airframe is designed for it - and in storing fuel and oxidizer onboard for ascent and a powered descent.

I don't think you're going to be able to modify a 747 to act as an SSTO. Sorry, but it wasn't designed for that environment.

Actually this article proves my idea would actually work.in particular the engines going from air breather to onboard oxgen breathers..

the747 would not use fancy hydrogen with all its problems...

it would use standard aviation fuel mixe with onboard oxgen.

skylon is too small a vehicle and has no wing lift...

its too complicated and expensive.its TOO MUCH like the space shuttle...with all its problems.

skylon is just a re-invention of the wheel and a very bad wheel at that....

the 747 would have engine thrust available from take off to orbit and back to landing again and would not be subject to those huge forces.

it would use small sustained acceleration and deceleration over much longer time periods. This is the most important advantage.longer time periods.

remember the time frame would be much larger for the vehicle to attain high velocities and also to go from high velocity to low velocity again using engines.


the 747 air frame may not be designed for that but it can be modifed....
in fact it already has been modified for various experiments already including
transporting the space shuttle!!....


i am afraid minor engineering issues are being used to oppose the idea in principle.

You are still comparing apples to oranges in terms of propulsive mechanisms. Turbofan engines do indeed burn fuel and air, but they make thrust by pumping atmospheric air, NOT by pumping internally stored fuel and oxidizer. THAT is why they have so much better fuel consumption than rockets. For your concept to work, you would have to carry all the air that is used for thrust as well as any used for oxidizing the combustion reaction...all this in addition to your fuel load. Since the TOGW of a 747 is just shy of 1,000,000 pounds, I cannot fathom how you plan to bring all this propulsive medium with you for a multi-hour journey. The 747 has a ceiling for a reason, it simply cannot make thrust much above 40k. That is not because it cannot sustain combustion due to lack of O2, but because there is not enough air for its engines to pump to make thrust to keep L=W. Even if you were to take off with only fuel and fly normally to 40k, and then gather up atmosphere and make thrust off your internally stored air, you are going to deplete that reserve of propulsive medium extremely rapidly with 4 CF-6's cumulatively pumping over a ton of air per second at 40k. These aren't minor engineering issues, these are show-stoppers.

Originally posted by Nipples
You are still comparing apples to oranges in terms of propulsive mechanisms. Turbofan engines do indeed burn fuel and air,.

THE 747 ENGINES ARE NOT FIXED IN STONE..THEY ARE DETACHABLE.

suitable engines as explained above can be used.

THEY HAVE ALREADY BEEN TESTED BUT LACK ANY VEHICLE IN WHICH TO BE USED.

turbofans can be replaced with jet engines as i have stated above.where is a will there is a way....

also thrust comes from the products of air/fuel or fuel/oxygen in a jet engine/rocket.



i am afraid you are letting minor engineering issues cloud the principles of sustained thrust which i have outlined above in detail.

[edit on 18-1-2007 by esecallum]

esecallum

I think you need to look a lot more closely at how space launchers work, there is no way to modify a 747 to get to orbit.

Have a look at these links

Gravity losses, still think you can accelerate slowly to orbit?
Specific impulse note Rockets = 450 Jets = 3000 try to work out why there is a difference and how this would effect your 747.



[edit on 18-1-2007 by Nacnud]

Even if it was possible for a 747 to get into orbit, which it IS NOT, the wings aren't swept enough for reentry. They would just simply shear off, they are not designed for such strains. Ever noticed how little wing area the shuttle has? That because it effectively uses its belly for air resistance to slow down, but is still travelling at speeds so high it requires a heat shield.

i am afraid minor engineering issues are being used to oppose the idea in principle.

You keep saying this but I really think you need to get a grasp of engineering yourself. Take a course on engines at least, to understand how wrong you are.

Maybe, just maybe, the idea could work in principle but the amount of modifications required to make a 747 space-worthy would stop it being a 747 all together. You might as well just design a new, more efficient shuttle from landing gear up.

Escallum, leaving the engine issue aside, even though you have not explained how the amount of fuel needed would be stored satisfactorily, even if such a thing were possible, I am curious how you would modify the 747 for orbital flight and return.

How do you modify the structure to withstand the stresses and how do you make sure the wings don't snap off?

'Strengthen them' doesn't cut it, how do you strengthen such a structure without adding so much weight that it can barely fly at all, never mind into space?

You seem to think that the issuer is just making the thing fly higher, its much more complex that. How do you propose to continue climbing after you have reached the point where the wings are completely ineffective? How do you plan to harness the thrust required without breaking the wing structure AND without making it too heavy?

The entire scheme is a ridiculous, impossible fantasy.

So just what engines are you referring to when you say the engines to be used already exist? Those 'Sabre' engines on the 'Skylon' were, and still are, pure fantasy. Show me an operational engine that produces 200000+ #s of thrust that can also fly supersonic. The GE90-115B only makes 120,000#s, and it can't fly supersonic. The GE4 would have powered the American concord competitor, and it only made 60,000+ #'s. I would classify it as the most powerful military/high-speed jet engine to ever reach an operational state. These 'Sabres' are paper engines...nothing more. I'll give you the benefit of the doubt in assuming that when you say swap turbofans with jets you mean swap turbofans with turbojets (since both are jet engines). What jet (turbofan or turbojet) engines operate higher than 100k? Perhaps the J93, or J57? Those will maybe get you to 100k, but with both being turbojets they will suck gas far faster than what the 747 is used to. Kiss that 10 hour mission goodbye. Now what's getting you from 100k to 300k? Not those jets that still don't have any atmosphere to pump to make thrust. Sure, they can burn their gas, and pump it and a stored oxidizer out the back, but that's not what jets are for. All you've done there is make a really bad rocket. So while you're running out of atmosphere to create lift the engines have to pick up more of the plane's weight by thrusting upwards...only they are starving for air too and are producing less thrust. What minor engineering issue are you going to fix to get around this major problem?