Dual air/space superiority?

[RayCav of ASVS]

Would it be better to combine air and space superiority into a single fighter type or have different types for each realm?

[Alyeska]

If you can make the fighter areodynamic without sacraficing its space fighting capabilities, then it should be possible.

[RayCav of ASVS]

If you can make the fighter areodynamic without sacraficing its space fighting capabilities, then it should be possible.

But it's not necessarily as simple as that

My point is, it seems as if most Sci-Fi universes seems to think it's a snap to make a dual role fighter.

But what if it's not?

All a space superiority fighter needs is an engine and some guns, with a pilot strapped in.

But an atmospheric fighter is a bit different. You need an aerodynamic shell, with possibly wings. But the biggest kicker is an internal bomb bay, depending on what weapons your using. No matter what the weapon is, chances are you could just hang it off a space fighter.

There are also other considerations. What if your sublight space propulsion drive emits toxic byproducts? You then need something with conventional fossil fuel engines for atmospheric work. Or what if the physics of your technology simply don't allow very good integration with the two realms, or not at all?

[The Yosemite Bear]

In one of my stories the Altherians flooded their world with their fighting, Their Snubfighters are considered very poor in space. However their fighters are very good in the air and underwater as the redundancies (The missile launcher's resemble torpedo Bays etc.) Still the skill of their pilots are often a strong factor.

[Omega-13]

biggest problem is $$

how much is it going to refuel fighters in space, that can't enter the atmosphere to refuel,
big money

[Evil Jerk]

It would all depend on your level of technology and resources, I'd assume.
With little of either I'd be expensive and pointless, it would have to be aerodynamic, be able to survive re-entry into an atmosphere, be able to function well in both an atmosphere and space, be able to reach escape velocities (or use boosters which would be clunky and expensive) and still have to be effective enough to not be a flying target.
It might be more efficient to simply make dedicated craft for each role.

[RayCav of ASVS]

biggest problem is $$

how much is it going to refuel fighters in space, that can't enter the atmosphere to refuel,
big money

Ummm, they just dock in space?

Really, we refuel planes air-to-air routinely. What makes you think it's going to be so difficult in space? Pumps are unaffected by the vacuum of space and it would make no difference. You can "spaceify" two F-15s and a KC-10 and they'll work in space just like they do on Earth.

[Omega-13]

biggest problem is $$

how much is it going to refuel fighters in space, that can't enter the atmosphere to refuel,
big money

Ummm, they just dock in space?

Really, we refuel planes air-to-air routinely. What makes you think it's going to be so difficult in space? Pumps are unaffected by the vacuum of space and it would make no difference. You can "spaceify" two F-15s and a KC-10 and they'll work in space just like they do on Earth.

uhh, think about this a little more clearly, how much do you think it costs to send up 20 tons of fuel? every couple weeks

[The Yosemite Bear]

Ahh but some Sci-Fi fighters can refuel for free using the atmospheres of planets and gas gaints.

[Omega-13]

Ok I thought we were talking about real life fighters being built

[RayCav of ASVS]

biggest problem is $$

how much is it going to refuel fighters in space, that can't enter the atmosphere to refuel,
big money

Ummm, they just dock in space?

Really, we refuel planes air-to-air routinely. What makes you think it's going to be so difficult in space? Pumps are unaffected by the vacuum of space and it would make no difference. You can "spaceify" two F-15s and a KC-10 and they'll work in space just like they do on Earth.

uhh, think about this a little more clearly, how much do you think it costs to send up 20 tons of fuel? every couple weeks

You do realize I'm implying a civilization that can do that easily, right?

[Omega-13]

Ummm, they just dock in space?

Really, we refuel planes air-to-air routinely. What makes you think it's going to be so difficult in space? Pumps are unaffected by the vacuum of space and it would make no difference. You can "spaceify" two F-15s and a KC-10 and they'll work in space just like they do on Earth.

uhh, think about this a little more clearly, how much do you think it costs to send up 20 tons of fuel? every couple weeks

You do realize I'm implying a civilization that can do that easily, right?

realised that too late! sorry, i thought we were talking about current real life,

[Enlightenment]

There's no way to build a dual-mode fighter that doesn't suffer from a major performance penalty in both modes. The reason for this is simple: the propulsion and control systems needed for atmospheric flight are mutually exclusive with those needed for spaceflight. An atmospheric fighter needs wings, air-breathing engines, and aerodynamic control surfaces. In space these would just be deadweight--and a lot of it. A space fighter needs a high-thrust rocket for main propulsion and an elaborate reaction control system for attitude control. In the atmosphere all this gear would be deadweight. Some degee of engine sharing between both modes is possible but this doesn't buy all that much because significant portions of the engine mass will be air- or space- exclusive. While it would be possible to build a dual mode fighter, the inherant performance penalties will be so bad that any dual mode fighter would simply be eaten alive by a fighter dedicated to operating either in space or in an atmosphere.


Incidentally, from a physics and engineering perspective space-based fighters make about as much sense as an Exploding Console. The fuel mass numbers come out very heavily in favor of expendable missiles sent on one-way trips rather than recoverable fighters.

[Neko_Oni]

Damnit Enlightenment beat me too it. I think the dead-weight point sums it up. Too much stuff that's only useful in one environment. However on the engine side of things didn't NASA recently release something 'bout an Aerospike engine, some sort of combination engine that can burn its fuel with normal air, then shut off the inlet for space use. Or am I getting sci-fi confused with reality again?

[Crown]

Aerospike Engine Rockwell started development of it in the 60's. Lockheed and NASA hoped to use it for their Venture Star project (replacment for the Shuttle). The engine has never made past static testing. Venture Star project has been cancelled. Although this could be because the entirely composite fuel tanks essential to the design could not be built with existing technology, and not the areospike's failure. However the issue is mute.

As for a air/space fighter with current tech, NO WAY! With Sci-fi tech, yes and easily so. I won't go into all the details, unless someone actually wants me to justify this, but I will say this every single fighter/plane today is a design comprimise there are no exceptions to this rule, it's the first thing I got taught.

The other thing I will say is that Enlightenment mentioned that a/c require air breathing engines, and space craft do not and thus dead weight arrises. You are correct in terms of today's tech but not sci-fi's tech. I mean you can have just one, and no dead weight, I mean how do you think they get off the ground anyway?

[Shaka[Zulu]]

this is reminiscent of the VF-1 vs thread... to expand upon what I said there, given equal tech levels, any multimode vehicle (be it a veritech, or just a dual environment -- ie air/space -- vehicle will get utterly pasted by a dedicated craft when in that craft's 'home' environment, unless the multi-mode vehicle can use its' abilities to advantage. Even then, such craft simply cannot carry the payload that a single-mode vehicle can.

[Crown]

You are assuming quite a lot there. Different fighter aircraft of today, that we lable 'air superiority', would get their asses handed to them if they weren't employed in their own optimal environment. Fighters are mostly designed in what is termed 'right side of the performance envelope' which means high thrust to weight ratio, low wing loading, and a design which is inherently unstable, not trimmed. While the dual role would get it's ass handed to it (maybe) if it were to try apply it's self in the low left of the envelope, it will out distance and out perform any fighter in the 'right hand side' of the envolope. It's operational altitude makes it invunerable to any kind of conventional attack, and it can exchange altitude for energy, thus giving it a decided advantage.

[Larz]

I would have to say it would be easier to just build to different ones. Though it is possible to build an aero-dynamic design, it would be harder to fit all the junk needed to use it in booth enviroments. I have a program called X-Plane where one can design their own airplane and hopes it flys. Though I've made some rather wonderfully fast crafts that could probably do very well in space with a couple of menuverability thrusters, in the atmosphere it tends to act like a 15G missle. Though I'm not saying that it couldn't be done, the cost to make smaller, lighter components that would keep the preformance bar high would be, IMO, a waste.

[Shaka[Zulu]]

Ahhh... X-Plane... Alas, I know it well. Havent yet built a plane from scratch, but have been known to tweak some, especially if I needed to convert from one version to another -- case in point the Atlantica BWB homebuilt, currently preparing for real-life flight testing just up 95 from me in Melbourne, FL. The Dynamic Wing Co. has a version of it for version 5.x, but I needed to import it to 6.x and tweak to get it to controllably fly at all, as 6.x includes a bunch of changes in the file format that messed the 5.x file up. Needless to say I am anxiously awaiting the new combat version!

[GrandMasterTerwynn]

I would have to say it would be easier to just build to different ones. Though it is possible to build an aero-dynamic design, it would be harder to fit all the junk needed to use it in booth enviroments. I have a program called X-Plane where one can design their own airplane and hopes it flys. Though I've made some rather wonderfully fast crafts that could probably do very well in space with a couple of menuverability thrusters, in the atmosphere it tends to act like a 15G missle. Though I'm not saying that it couldn't be done, the cost to make smaller, lighter components that would keep the preformance bar high would be, IMO, a waste.

Ahhh, I have the exact same program, and I have come up with several successful designs. I thought them up for my own sci-fi universe, and I thought I'd see if they'd actually work.



I called this one the Vincent. At lower speeds (< 500 MPH) it's fairly agile (not nearly as agile as modern fighters.) At faster speeds, it's sluggish and has marked instabilities.



I call this one the Trident. The three engine nacelles actually give it a lot of maneuverability (depending on how you manage the throttle.) It approaches the agility of modern fighters, but improper throttle management can make it rather unstable.



This isnt a human-designed fighter (but it is from my universe.) It is from the Star League. It is a standardized light-fighter called the Phalanx It bears a rather unfortunate resemblance to some TIE variant. Even more astonishing . . . it flies. It flies very, very well too. It turns on a dime (it's just as maneuverable as modern air superiority fighters,) and it's reasonably fast. The two Human fighters listed above would be cannon fodder for this craft in the atmosphere. (In space, it's a slightly different story.)

[GrandMasterTerwynn]

Ahhh... X-Plane... Alas, I know it well. Havent yet built a plane from scratch, but have been known to tweak some, especially if I needed to convert from one version to another -- case in point the Atlantica BWB homebuilt, currently preparing for real-life flight testing just up 95 from me in Melbourne, FL. The Dynamic Wing Co. has a version of it for version 5.x, but I needed to import it to 6.x and tweak to get it to controllably fly at all, as 6.x includes a bunch of changes in the file format that messed the 5.x file up. Needless to say I am anxiously awaiting the new combat version!

Bizarre craft built entirely from scratch? That's me.

And a combat version? Wow!

[Enlightenment]

I won't go into all the details, unless someone actually wants me to justify this, but I will say this every single fighter/plane today is a design comprimise there are no exceptions to this rule, it's the first thing I got taught.

True. But the design compromises necessary to make an F-22 (cost/performance, external stores/supercruise, performance/radar signature, aerodynamic stability/performance) are far different than the kind of tradeoffs that are necessary in a dual mode fighter. A fighter that's dedicated to one mode or the other can play the overall tradeoffs much better in its area of expertise than can a dual mode fighter that much play the tradeoffs in both operating modes. As such a dual mode fighter would be bait to any dedicated fighters.

The other thing I will say is that Enlightenment mentioned that a/c require air breathing engines, and space craft do not and thus dead weight arrises. You are correct in terms of today's tech but not sci-fi's tech. I mean you can have just one, and no dead weight, I mean how do you think they get off the ground anyway?

Fuel load. Chemical rocket engines burn an incredible amount of fuel per unit time. The quantity of fuel necessary to keep a rocket running for the hours that an air-fighter has to operate is simply not transportable on a fighter-sized vehicle.

While dual mode nuclear engines would be fairly easy to build, the atmospheric exaust would be radioactive enough to class as a weapon of mass destruction. Look up project pluto sometime to see what I mean.

[Shaka[Zulu]]

yeah... when it (X-Plane Combat!) finally ships, we will be able to design our own weapons, mount them on the airframe of our choice, and do some really interesting stuff!

[Shaka[Zulu]]

Fuel load. Chemical rocket engines burn an incredible amount of fuel per unit time. The quantity of fuel necessary to keep a rocket running for the hours that an air-fighter has to operate is simply not transportable on a fighter-sized vehicle.

not necessarily true... dual mode conventional engines such as ram-rockets and turborockets have potential, but would likely be best suited to interception and satellite hunting -- I am thinking that they would either use a Black-Horse flight profile (tanking up at altitude from a KC) and then proceediing to space, or carrying drop tanks for the extra fuel they need.

While dual mode nuclear engines would be fairly easy to build, the atmospheric exaust would be radioactive enough to class as a weapon of mass destruction. Look up project pluto sometime to see what I mean.

I was wondering when Pluto would rear its' head... man that thing would have been pure evil if it ever flew. That said, there may be other ways to use nuclear to drive an air-breathing or dual-mode propulsion system that wouldnt be so problematic.

[Crown]

True. But the design compromises necessary to make an F-22 (cost/performance, external stores/supercruise, performance/radar signature, aerodynamic stability/performance) are far different than the kind of tradeoffs that are necessary in a dual mode fighter. A fighter that's dedicated to one mode or the other can play the overall tradeoffs much better in its area of expertise than can a dual mode fighter that much play the tradeoffs in both operating modes. As such a dual mode fighter would be bait to any dedicated fighters.

You are correct, which is why I conceeded on the point if the dual space/air fighter was meant to be used as a 'ground attack' a/c, however in the pure fighter sense it would be untouchable. It's combat altitude proves this. Remember that one of the reason's that the F-22 outperformes most (if not all fighters today) is because it's optimised for the RHS of the performance envelope. A dual mode air/space fighter will leave it for dead.

Fuel load. Chemical rocket engines burn an incredible amount of fuel per unit time. The quantity of fuel necessary to keep a rocket running for the hours that an air-fighter has to operate is simply not transportable on a fighter-sized vehicle.

While dual mode nuclear engines would be fairly easy to build, the atmospheric exaust would be radioactive enough to class as a weapon of mass destruction. Look up project pluto sometime to see what I mean.

Again you are correct, I did say from the start that if we are dealing with existing tech that it wouldn't stand a chance. And if this post was in the Science, Logic and Morality forum we wouldn't even be having this discussion. However since the thread is in the Other Sci-Fi forum, we have many more exotic toys to play with.

If I have misunderstood that this thread was meant to be a serious topic about existing tech, then I apologise, however if it is just meant to be a topic about using tech we see in Sci-Fi, then I stand by my statements.

X-Plane, good program, however not entirely accurate. A group of my friends designed a Stealth Fighter for the AIAA comp last year, and they discovered that when they used X-Plane their a/c which had air breathing engines performed admirrably in outer space!