AHChallenge: Rocket-powered Aircrafts as Mainstream in Military Service

Yes, the challenge is to make rocket-powered aircrafts beat jet-powered ones in military service.

I know that there are MANY disadvanges in rocket aircraft, but how can we solve them.

Thanks in advance!
 
Space fighters maybe. Atmospheric aircraft with rocket engines suffer from to many limitations to be effective as anything but point defense in a very narrow window. Even then they were death traps for the pilots.
 
Rockets are inherently short ranged. In something as small as a fighter airframe, at best you could have enough range for a point defense interceptor. It could never completely replace other forms of propulsion for roles which require longer legs.
 
The big problem is that rockets carry their own oxygen with them, but at the level where theres not enough oxygen to sustain a jet engine the atmosphere gets a bit thin to steer aircraft. This is why the NF104 had rocket thrusters for attitude control. I struggle to imagine scenarios where it is militarily useful to fly and fight at altitudes above 100,000 ft where rocket engines are needed.
 
Niche roles perhaps?

Point defense interceptors have already been mentioned, though how these have any real advantage of SAMs is not clear to me.

Long range bombers (Sanger anyone?) might be another possibility however. Assume that truly effective ABMs (an outgrowth of SAMs?) are developed that make ballistic missile systems ineffective but are not capable of dealing with manned systems. One might posit that this would be because manned systems can perform in unexpected ways (unlikely), or simply that the various countermeasures for dealing with ABMs/SAMs are so expensive that manned (i.e. non-disposable) systems are the only way to use them in a cost effective manner. Either way, for some roles manned rockets might be an option...

Along the same lines, ultra-high speed penetrators (either for strike operations - unlikely - or recon operations) might be another niche. You would have to assume away satellites (for recon) and once again presume very effective SAMs/ABMs, but this is not entirely unreasonable.
 
... the various countermeasures for dealing with ABMs/SAMs are so expensive that manned (i.e. non-disposable) systems are the only way to use them in a cost effective manner.

Manned aircraft are generally non-disposable, but the reverse is not always true - non-disposable aircraft do not have to be manned. It's not impossible to imagine a drone or remote-piloted aircraft to conduct these missions, especially if they're as dangerous as suggested. Then, of course, people worldwide will thrill to the daring exploits of "Semi-autonomous delivery system FB-37" (1). And who could forget the 60's movie "Taxi" with it's unforgettable portrayal of warhead bus #179?

Basically it's very hard to think of any roles which require a) rocket propulsion and b) a human crew, and f1b0nacc1 has dealt with those I think.

(1) Which actually sounds like an anime, now that I think about it, although the delivery system would have to resemble a young girl (for reasons not adequately explained) and probably have an improper relationship with it's/her servicing center.
 
What about parasite fighters, like the FICON setup in the 50s? Use a conventional mothership for delivery to target, have the rocketplane dash in and bomb the place, then rendezvous again for return to base.
 
What about parasite fighters, like the FICON setup in the 50s? Use a conventional mothership for delivery to target, have the rocketplane dash in and bomb the place, then rendezvous again for return to base.

Interesting idea. Since we're pretty much ASB already, how about a nuclear-powered dirigible mothership?
 
Interesting idea. Since we're pretty much ASB already, how about a nuclear-powered dirigible mothership?

If we're going for rule-of-cool, may I suggest we keep the nuclear propulsion, but make it a gigantic flying wing instead of a dirigible, like the Lockheed CL-1201.
 
If we're going for rule-of-cool, I say we keep the nuclear propulsion, but make it a gigantic flying wing instead of a dirigible, like the Lockheed CL-1201.

Better speed, but higher P/W ratio required to remain aloft. By my estimate, the highest ratio achievable with nuclear is a fast reactor using boiling plutonium 239, probably circulating in graphite pipes through a core open to the atmosphere - a turbojet, essentially. God help us if there's a core leak... escort aircraft better carry radiation detectors.
 
Better speed, but higher P/W ratio required to remain aloft. By my estimate, the highest ratio achievable with nuclear is a fast reactor using boiling plutonium 239, probably circulating in graphite pipes through a core open to the atmosphere - a turbojet, essentially. God help us if there's a core leak... escort aircraft better carry radiation detectors.

The CL-1201 group wanted to use a solid fuel reactor with a binary liquid sodium coolant cycle powering heat exchangers. The document I have doesn't specify if it would be fast or moderated, but the ANP program back in the 50s wanted to use beryllia moderators; I'd guess they'd do the same.

Interestingly, a NASA-Lewis study back in the 70s calculated that, with a large enough plane, you eventually reach a point where the P/W ratio of the nuclear system is better than the conventional system, if you count the fuel as part of the weight. This is because the nuclear system mass is dominated by the shielding, which is roughly proportional to the reactor surface area, which scales sublinearly with power. The breakeven point is supposedly somewhere between one and five million pounds, depending on whose study you read.
 
Have no ICBMs. I don't know how you would butterfly that away, but this will lead to more strategic bomber development during the Cold War, which will in turn encourage development of point-defense interceptors, which will either be partially or fully rocket-powered.
 
I don't know what assumptions were made for that study, but there are lots of ways to get the P/W ratio up (in theory):

1. Fast reactor - no moderator, less bulk, less shielding.

2. Isotopically pure fuel.

3. Only provide shielding on the crew-ward side. Everyone else better stand the fuck back when the reactor is on.

4. Higher temperature operation. An airborne reactor is of course ultimately air cooled, which limits heat wasting; if you operate at the boiling point of plutonium you get about 20x the work/waste ratio (and thus 0.05 as much core for a given airflow) as compared to a commercial power reactor.

5. Direct air cooling of the core, eliminating a lot of pumps, pipes, and heat exchangers.

6. No sissified redundant backup cooling systems or decay heat removal. What, do you want to live forever? We only shut the reactor down at airfields that have cooling water pumps.

7. Molten salt/metal coolant. Low pressure eliminates the need for a massive pressure vessel for the core.

8. On-line purging of xenon from liquid fuel.

9. Sacrificial neutron shielding using using separated isotopes of cadmium and gadolinium?

I bet an aircraft of only a hundred tons could achieve the same P/W ratio as a jet, without counting the fuel weight. And of course, it can fly for years without landing.

EDIT: Looks like solid gold might be a more cost-effective shield for fast neutrons. Even more cooler.
 
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Point defense vs area defense

Have no ICBMs. I don't know how you would butterfly that away, but this will lead to more strategic bomber development during the Cold War, which will in turn encourage development of point-defense interceptors, which will either be partially or fully rocket-powered.

I don't think so. The more dangerous the weapons being carried by the bomber (nukes are ALWAYS dangerous, but bigger are more dangerous, and if they have sophisticated penetration aids/decoys, more dangerous still), the longer the range that you want to intercept them at. More to the point, point-defense fighters require very, very good C3I systems (think of the Fighter Command in the BOB, it wasn't the Spitfire/Hurricanes that beat the Luftwaffe, it was the far superior C3I - not just radar but the ability to vector in the fighters) because of their short range. Certainly point defense fighters will be useful, but in a world without ICBMs (and you can't buttefly them away...though you could make useful defenses against them I suppose), long range interception and area defense (AWACS + long range fighters/missiles/SAMs) would be far more important.

As mentioned earlier, the interceptor (with the exception of a few specialized point-defense systems...hardly discernable from SAMs) isn't the place you would use rockets, but the bombers (or any delivery system...) might be
 
Soo, a rocket-powered fighters are basically useless?
Only suborbital bomber suitable with this technology?
 
Soo, a rocket-powered fighters are basically useless?
Only suborbital bomber suitable with this technology?

Rocket powered fighters would be fast and function OK at very high altitudes, but have a very short range. In any TL where SAMs are available, they'll be a better option.

The strengths of rocket powered fighters seem to be speed and the (debatable) value of having a human pilot. So basically we need a situation where human pilots are required in order to achieve the fighters role, and the fighter can do it's job very close to it's base. A rapid-response/high-altitude point-defence interceptor in the period before electronics make guided weapons possible seems like the only option.
This is a very difficult situation to plausibly achieve, to put it mildly. Looking at a far-out possibility, however, how about an aircraft designed to intercept sub-orbital bombers in the 1940s? If there is somehow a situation where for example Sanger's Amerika Bomber is considered a credible threat, the US might decide they need something to prevent it dropping it's payload - thus, your rocket-powered interceptors.

Dog alone knows how you'd engineer that sort of scenario arising, though.
 
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