This is a discussion on Air Launched ICBM? BAE's Sweet Design. within the Missiles & WMDs forum, part of the Global Defense & Military category; I had seen Minuteman 1 ICBM Air Launch - YouTube of a Minuteman I being Air Launched out the back ...
I had seen Minuteman 1 ICBM Air Launch - YouTube of a Minuteman I being Air Launched out the back of a C-17, so I have known for a long time that the 'Air Launch' concept had been developed in the past. However I just came across a blog that detailed BAE's fairly recent patent for an aircraft that vertically stores and launches multiple ICBMs.
I am going to put practicality aside for a moment and just say...this is awesome.
Let's suppose that at the hieght of Lemay's alert force, we had Air-Launched ICBMs. What leg of the triad would they fall under? Would they be considered a bomber weapon, or just alternate launch platform for an ICBM? Would they constitute a fourth leg to the triad (Quadriad?). I think that they would fall under the ICBM leg, but I am open to alternate suggestions.
I suppose that there are commercial uses for this as well, at least in small satellite spacelift. It would significantly increase spacelift capacity, and maybe even reduce the cost of spacelift.
Last edited by Deterrence Wonk; August 21st, 2011 at 02:22 PM.
Reason: typo
It would significantly increase spacelift capacity, and maybe even reduce the cost of spacelift.
Physics don't agree with you there.
Launching a SLV hanging from a parachute (read: negative initial velocity vector) will need more thrust to bring the final stage to orbital velocity than launching it from the ground.
The idea is quite reminiscent of this Popular Science article from a few years back.
As far as the thrust issue goes. What kato says is true, although it seems to me like there still might be fuel, weight, and payload savings to be had. Starting at a higher altitude would conceivably reduce the distance the rocket would have to propel itself, distance it would have to otherwise burn fuel travelling...
Air launching can get you benefits, you are above a significant portion of the earths atmosphere and hence most of the drag (particularly at high speed). Ideally you would also take advantage of the launch platform kinetic energy (speed), imparting it to the missile. (ie 1000km/hr). You can also get much closer to the target, its also atypical of a ICBM launch so may not be picked up or atleast buys you more time.
With this system you get additional range, a sneaky launch platform that can respond to changes much quicker than a sub.
Starting at a higher altitude would conceivably reduce the distance the rocket would have to propel itself
To achieve orbit you don't need altitude, you need speed. Roundabout 7.8 km/s.
Quote:
Originally Posted by StingrayOZ
Ideally you would also take advantage of the launch platform kinetic energy (speed), imparting it to the missile. (ie 1000km/hr)
You'd need to fire in the direction of your speed vector for that (there are airlaunched space launcher that do that). Not shove it out the back and let it drop suspended from a parachute.
On a side note (not mentioned yet) the launch aircraft in 1974 for that Minuteman I was a C-5A, not a C-17. The missile was pulled out at 20,000 ft and dropped by a full 12,000 ft before firing the first stage.
Well one of the problems with rocket motors is that they dont perform as well at certain hights.
Where as one design might work well at low level and be less fuel efficent/less powerful at high level the reverse is also true.
Plus there is the speed advantage as was said.
I think if we were to do such a thing today it would function more like Spaceship 1 and its carrier.
Quote:
Originally Posted by Kilo 2-3
The idea is quite reminiscent of this Popular Science article from a few years back.
As far as the thrust issue goes. What kato says is true, although it seems to me like there still might be fuel, weight, and payload savings to be had. Starting at a higher altitude would conceivably reduce the distance the rocket would have to propel itself, distance it would have to otherwise burn fuel travelling...
I think if we were to do such a thing today it would function more like Spaceship 1 and its carrier.
Look up Pegasus. It's been launched over 40 times from B-52s and TriStars. The wikipedia article also expands a bit on why the air launch isn't viable for "boosting", and why air launch is used at all.
Launching a SLV hanging from a parachute (read: negative initial velocity vector) will need more thrust to bring the final stage to orbital velocity than launching it from the ground.
I was referring to the BAE design, not the video... BAE's desgin would have no negative velicity vector. Even so, that would depend on many factors.
Space lift from an air launched platform is not new but BAE's design would 'wholesale it'
What matters when getting something into space is how long it has to accelerate to get to a orbiting velocity (or at least an orbit that takes it to its target when full orbit isn't achieved). A c5 taking a minuteman I to 20,000 isn't a great system, but I doubt that's what bae has planned. If a missile has great thrust and can make it to an altitude where air friction is greatly minimized as fast as possible, it will have more fuel to burn without resistance. So, if you can start it from 30,000 feet, do it! And even if it doesn't confer a great economic advantage, which I think it does, it still adds to deturrence. Seems like air launches are a good idea.
Does this mean BAE designers play too much ace combat. Because to have a aircraft that can vertically launch ICBM's you would need a very big aircraft.
Does this mean BAE designers play too much ace combat. Because to have a aircraft that can vertically launch ICBM's you would need a very big aircraft.
Big aircraft do exist. A Minuteman III is well within the weight capacity of a C-5 Galaxy.
Air Launch gives the operator massive flexibility for both commercial and military applications. Obviously, launching as close to the equator as possible yields advantages for commercial uses that's why the French built their Spaceport in Guiana and why SeaLaunch is so viable (in concept). Air Launch gets the operator to the optimum launch location without having to invest billions in a facility, or building a vulnerable military.
Designing a launch vehicle for Air Launch adds some new variables to the load calcs but as Orbital has shown with the Pegasus this isn't an insurmountable problem. I've always wondered about possible military applications for the Pegasus. How hard would it be to put a few MARV's in a bus for a ride in a sub-orbital Pegasus? Hell, even a few conventional warheads - that would be a nice 1st effort at a Global Strike platform without having to develop a Mach-15 vehicle.
The problem is not the weight but the length. To vertically launch a Minuteman III from an aircraft the cargo compartment needs to be over 19 meters high, the C-5 Galaxy is slightly over 4 meters. Even the Super Guppy is less than 8 meters.
Whatever missile BAE is assuming, it has to be a lot smaller than an 18 meter Minuteman III.
