I've heard the USAF are interested in Starship for delivering payloads anywhere in the world in minutes, but I've not heard about any other interest.

If you have a stage 1 rocket that can deliver a hypersonic payload over some distance, then fly back for re-fuelling and re-arming in a short period of time (maybe minutes, maybe hours), why isn't this making bombers obsolete? Maybe fighters as well for that matter as they'd have no bombers to fight against.

Targeting can be done by stealthy drones or satellites or troops on the ground. I think they could even maybe use existing but adapted guided munitions.

You wouldn't want the fancy launch tower that SpaceX uses, just some landing legs. Ground support equipment would be, depending on the size of the rocket, a few trucks of methane/oxygen and a crane to load the weapons. The ground footprint would be smaller than an airfield, and could easily be moved. Deployment on a ship would also be possible without huge and hugely expensive aircraft carriers.

As for cost - what is the B-21 programme costing compared to the Starship programme?

I'm trying to think what they couldn't do - and it's only really loitering for ECM and reconnaissance, but you'd use drones for that. The rocket would be so fast, even for targets hundreds of miles away, that you should still be able to hit moving targets.

Anyway, waiting to be shot down in flames.

A bomber that you can see on radar 500 miles away would probably not get to target or return home to be reused very often. It takes more than a few trucks of fuel to fill a Starship for the return trip, and the methane and LOX need to be much higher grade than normal gas plants can put out.
But the Air Force is very interested in getting certain payloads to any place on Earth in an hour. As cheaply as they can build Starships, disposable ones might be more practical for military uses.
Everybody is waiting to see how the thing works out before they make any detailed plans.

Nomadd wrote:

A bomber that you can see on radar 500 miles away would probably not get to target or return home to be reused very often. It takes more than a few trucks of fuel to fill a Starship for the return trip, and the methane and LOX need to be much higher grade than normal gas plants can put out.
But the Air Force is very interested in getting certain payloads to any place on Earth in an hour. As cheaply as they can build Starships, disposable ones might be more practical for military uses.
Everybody is waiting to see how the thing works out before they make any detailed plans.

You talk about Starship, but I'm talking about rapidly reusable rockets generically, and the first stage of a rocket, not starship. I can't imagine the requirement would be for a rocket anywhere near the size of super heavy. That has a payload of 1200 tons. I don't know what the payload of the B-21 is, but probably less than 20 tons. I guess the size of it would depend on the requirements.

As for being seen 500 miles away - well maybe, but there's no SAM that can hit that far, and by the time the munitions were in range the first stage would be travelling back to base. Also, the rocket and its munitions would be travelling hypersonically. Much harder for a SAM to hit, and certainly much harder to hit than any manned aircraft, stealth or not.

As for fuel quality, you're not trying to reach orbit so you have much more performance margin. The BE-4 runs on natural gas so I don't see it as a big issue.

Sorry, I don't feel shot down in flames yet. although I do see how everyone would be waiting to see how it turns out.

If you are just talking about using the Space X reusable launcher to heave critical payloads into a surrounded city or area, then it may work. Medical supplies might be critical enough to worth the cost. Just need some small retro and parachutes and you can probavly hit a mile wide landing zone.

bt

kurtverbose wrote:

Nomadd wrote:

A bomber that you can see on radar 500 miles away would probably not get to target or return home to be reused very often. It takes more than a few trucks of fuel to fill a Starship for the return trip, and the methane and LOX need to be much higher grade than normal gas plants can put out.
But the Air Force is very interested in getting certain payloads to any place on Earth in an hour. As cheaply as they can build Starships, disposable ones might be more practical for military uses.
Everybody is waiting to see how the thing works out before they make any detailed plans.

You talk about Starship, but I'm talking about rapidly reusable rockets generically, and the first stage of a rocket, not starship. I can't imagine the requirement would be for a rocket anywhere near the size of super heavy. That has a payload of 1200 tons. I don't know what the payload of the B-21 is, but probably less than 20 tons. I guess the size of it would depend on the requirements.

As for being seen 500 miles away - well maybe, but there's no SAM that can hit that far, and by the time the munitions were in range the first stage would be travelling back to base. Also, the rocket and its munitions would be travelling hypersonically. Much harder for a SAM to hit, and certainly much harder to hit than any manned aircraft, stealth or not.

As for fuel quality, you're not trying to reach orbit so you have much more performance margin. The BE-4 runs on natural gas so I don't see it as a big issue.

Sorry, I don't feel shot down in flames yet. although I do see how everyone would be waiting to see how it turns out.

There's a big difference between acquiring a target with a SAM and the maximum intercept range. The further away they pick it up, the more accurately they can intercept it.
The BE-4 runs on purified methane, not regular natural gas, and performance margin isn't the issue. Not working when the fuel is wrong is the issue. Including the LOX. Making 95% pure oxygen is easy. 99.9% pure isn't.
And in case you forgot to read your own post, you were the one talking about Starship. It's also the only fully reusable rocket on the boards at the moment unless you want to talk about somebodies Powerpoint.

Nomadd wrote:

There's a big difference between acquiring a target with a SAM and the maximum intercept range. The further away they pick it up, the more accurately they can intercept it.
The BE-4 runs on purified methane, not regular natural gas, and performance margin isn't the issue. Not working when the fuel is wrong is the issue. Including the LOX. Making 95% pure oxygen is easy. 99.9% pure isn't.
And in case you forgot to read your own post, you were the one talking about Starship. It's also the only fully reusable rocket on the boards at the moment unless you want to talk about somebodies Powerpoint.

Sorry, I'm not buying the SAM argument. However easy it is to intercept a hypersonic missile, it's a lot harder than hitting any bomber, even a stealth one. And by the time it was in range you'd be dealing in submunitions, not the launch rocket. Try hitting maybe 20 hypersonic submunitions at the same time.

I don't know about the rocket fuel. To me it you either try and have a more tolerant engine or you have more ground equipment. One way or the other it's not a deal breaker.

If you'd read my post you'd see that I mentioned Starship because it's the only time a rapidly reusable rocket has been talked about by the military, and then only for transport.

I agree this is powerpoint at the moment, but I'm a bit surprised it's not been talked about more.

I'm not sure what the application would be.

Bombers are required anyway for their ability to loiter as well as their ability to identify and track moving targets. You're not going to replace them.

For short range tactical strikes against fixed positions, traditional air-launched (hypersonic or subsonic) cruise missiles work well.
A ship-launched cruise missile could consider a reusable first stage but I'm not sure how easy or safe it would be to recover the stage on a ship. Reusability also comes with reduced performance, which may be important for the restricted volume and weight available on ships.

For longer range strategic strikes, the scenario you'd use them in doesn't really expect significant reuse. ICBM sites are prime targets for both first strikes and counterattacks by hostile ICBMs.

mxaxai wrote:

I'm not sure what the application would be.

Bombers are required anyway for their ability to loiter as well as their ability to identify and track moving targets. You're not going to replace them.

Already countered. You use drones or satellites or troops on the ground for targeting, including moving targets.

mxaxai wrote:

For short range tactical strikes against fixed positions, traditional air-launched (hypersonic or subsonic) cruise missiles work well.

They do work well. Subsonic ones are more vulnerable. Both are more expensive because of their lack of reusability.

mxaxai wrote:

A ship-launched cruise missile could consider a reusable first stage but I'm not sure how easy or safe it would be to recover the stage on a ship.

Yes, that might be very difficult.

kurtverbose wrote:

mxaxai wrote:

A ship-launched cruise missile could consider a reusable first stage but I'm not sure how easy or safe it would be to recover the stage on a ship.

Yes, that might be very difficult.

Yeah it's one thing to land on a cheap autonomous barge in calm weather and another to land on the helipad of a multirole ship under all circumstances. Not to mention the risk of injuries to the crew, or even the loss of the entire ship, if something goes wrong.
How many boosters has SpaceX lost on landing? Would you rather throw away a rocket stage worth $1M or risk a ship and crew worth 100 - 1000 times that?

kurtverbose wrote:

Already countered. You use drones or satellites or troops on the ground for targeting, including moving targets.

The main point is the rapid and precise response ability of a crewed (or uncrewed) aircraft in the immediate vicinity of the battlefield. Traditional artillery can work as well but rockets launched from far away just can't replace a proper close air support. We're talking about response time differences between 30 seconds for traditional tactical support and 10-30 minutes for medium range missiles (even hypersonic).

mxaxai wrote:

Yeah it's one thing to land on a cheap autonomous barge in calm weather and another to land on the helipad of a multirole ship under all circumstances. Not to mention the risk of injuries to the crew, or even the loss of the entire ship, if something goes wrong.
How many boosters has SpaceX lost on landing? Would you rather throw away a rocket stage worth $1M or risk a ship and crew worth 100 - 1000 times that?

Sure, there are times when you'd rather throw away the first stage than risk the ship and crew. Falcon 9 was the first rocket to land on a drone ship. They have no need to land on any other kind of ship, or during a storm. If they needed to they probably could develop a rocket that could, so but don't pretend this is a deal breaker on the concept. It just isn't.

mxaxai wrote:

The main point is the rapid and precise response ability of a crewed (or uncrewed) aircraft in the immediate vicinity of the battlefield. Traditional artillery can work as well but rockets launched from far away just can't replace a proper close air support. We're talking about response time differences between 30 seconds for traditional tactical support and 10-30 minutes for medium range missiles (even hypersonic).

Ok, so you're talking about close air support, and only that, because a rocket is maximum 10 minutes from hitting a target. Your $200 billion B-21 project is just about close air support, because after 10 minutes a rocket is better. I think I'd rather spend my $200 billion else where.

kurtverbose wrote:

Ok, so you're talking about close air support, and only that, because a rocket is maximum 10 minutes from hitting a target. Your $200 billion B-21 project is just about close air support, because after 10 minutes a rocket is better. I think I'd rather spend my $200 billion else where.

It's not just about that but it's an important mission and it's a relatively frequent mission. You can't just discard it.
If you're designing an aircraft for that, you might as well develop something that can do all other strike missions too. And some aircraft, like the F-35, are not only good strike aircraft but can defend your airspace against intruding aircraft. They can even be reused after each mission, like your proposed rocket.

Your rocket system would have one role only, strategic strikes against fixed targets, and the military already has something for that. They're not going to spend $200 billion in development cost just to save $1 million per rocket launch.

How would one differentiate this conventionally armed system from a nuclear one?

Routine spacecraft launches are announced well in advance and are thus easy to identify as non-hostile. Your proposed system I assume would not be announced in advance - it’ll look like a nuke.

Non starter on this point alone.

mxaxai wrote:

Your rocket system would have one role only, strategic strikes against fixed targets, and the military already has something for that. They're not going to spend $200 billion in development cost just to save $1 million per rocket launch.

You keep repeating that but it's not true. You could hit moving targets, and multiple small targets, and it would be very hard to defend against, unlike existing systems.

Also, where do you get $200 billion for a rocket system from?

zanl188 wrote:

How would one differentiate this conventionally armed system from a nuclear one?

Routine spacecraft launches are announced well in advance and are thus easy to identify as non-hostile. Your proposed system I assume would not be announced in advance - it’ll look like a nuke.

Non starter on this point alone.

But there are a lot of nuclear delivery systems that can be confused with conventional, not just ICBM's. Cruise missiles can and are nuclear armed, existing bombers can and do carry nuclear arms. There even used to be nuclear artillery.

kurtverbose wrote:

But there are a lot of nuclear delivery systems that can be confused with conventional, not just ICBM's. Cruise missiles can and are nuclear armed, existing bombers can and do carry nuclear arms. There even used to be nuclear artillery.

A quick review of nuclear deterrence strategy:

With an ICBM the other guy has maybe 10 or 15 minutes to decide how to respond to an unannounced ICBM or missile launch. He has to get it right, millions of lives are at stake. Is it worth it to possibly mistake a transport booster with an ICBM? No.

With a manned bomber the warning time goes way up, hours instead of minutes.

Cruise missiles? U.S. ground and air launched cruise missiles with nuclear warheads were scrapped 30 years ago. Even the ALCM carrying B-52Gs, structurally modified to be easily identified, were scrapped long ago. What’s left? ship and sub based Tomahawks. Good luck proving shipbased Tomahawks “are” nuclear armed. My guess, the nuke armed Tomahawks are in a weapons depot somewhere far away from any ship or sub. Warning time on one of these is days and probably weeks.

IDK, maybe things have changed since Putin and Trump nullified the treaties. I’m guessing not.