I read that Adronos bought a former General Dynamics' plant in Mississippi to mass produce its solid fuel. Mass production could bring prices down. Especially with potential foreign military clients.
 
Why doesn't SpaceX use solid fuel? Business choice?

They are not energy-efficient. They are storable, durable, simple - but their efficiency is way below liquid ones. For the military missile, the simplicity of handling and durability is important. But for commercial rocket the efficiency is the core parameter.

Also, they do not fit into SpaceX reusability program. Solid engines could not be stopped and re-started. There is no practical way of "switching off" solid-fuel rocket once it get ignited. The way space boosters do that (if they needed to switch off the thrust at some exact moment), is basically by cancelling thrust: they blow side ports in solid fuel booster casting, so the hot gases could escape before reaching the nozzle - thus cancelling the thrust, but the fuel would continue to burn anyway.
 
Solid engines could not be stopped and re-started. There is no practical way of "switching off" solid-fuel rocket once it get ignited.
I believe it's possible - Orionblamblam will know more, but it seems to involve rapidly increasing the nozzle area, causing a drop in chamber pressure and the flame being extinguished. I think it's even possible to make a restartable solid motor this way.
 
I believe it's possible - Orionblamblam will know more, but it seems to involve rapidly increasing the nozzle area, causing a drop in chamber pressure and the flame being extinguished. I think it's even possible to make a restartable solid motor this way.
I'm not sure it would be reliable. The channels, drilled through the solid fuel mass to ensure regular efficient burn would most likely lose shape, so the next ignition would be irregular, with thrust & impulse varying chaotically.
 
Why would the flame be extinguished? Surely the charge would continue to burn but just not push any more. Also ‘rapidly increasing the nozzle area’ would shock the charge to some extent and I remember 60 years ago handling a cuckoo motor with exaggerated care while installing it in case that very thing happened.
 
I believe it's possible - Orionblamblam will know more, but it seems to involve rapidly increasing the nozzle area, causing a drop in chamber pressure and the flame being extinguished. I think it's even possible to make a restartable solid motor this way.
I'm not sure it would be reliable. The channels, drilled through the solid fuel mass to ensure regular efficient burn would most likely lose shape, so the next ignition would be irregular, with thrust & impulse varying chaotically.
Los Alamos has made a start on the idea:

 
I'd swear I recall seeing articles from the late 50s to mid 60s where various companies were working on versions of solids that could be started and stopped and then re-started along with being able to throttle them on-demand.

Randy
 
I wonder if this ALITEC propellant is used in the AIM-260's rocket-motor?
You definitely want a high thrust and long burning engine for that monster.

Definitely. I suppose that another way to extend range by reducing drag would for the launch lugs to fold away after launch just like they do on the AARGM-ER.
 
I wonder if this ALITEC propellant is used in the AIM-260's rocket-motor?
You definitely want a high thrust and long burning engine for that monster.

Definitely. I suppose that another way to extend range by reducing drag would for the launch lugs to fold away after launch just like they do on the AARGM-ER.
And to fly as high as possible during the cruise phase, before diving down at the target. I think I've seen 100kft plus for the AMRAAM.
 

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