NKC-135 Airborne Laser Laboratory

[KJ_Lesnick]

I was doing a search online and kind of stumbled upon an image of a modified KC-135 used for USAF systems command which involved a carbon-dioxide laser that was designed to destroy missiles.

Considering it was able to destroy drones and even sidewinders in tests, and sidewinders are really small targets (thinner than my waist, and with the exception of the AIM-9J/N, shorter than an NBA sized basketball hoop), and move at a decent clip: I'm curious -- if it's not classified, why it would be cancelled?

 

[stealthflanker]

Ausairpower actually have good article on it :

High Energy Laser Directed Energy Weapons

High Energy Laser Directed Energy Weapons

www.ausairpower.net

Regarding cancellation/retirement of the aircrafts, according to the article. It's because its demonstrator status and some problems encountered during tests which need new innovations (e.g adaptive mirror) To solve.

 

[fredymac]

The Airborne Laser Lab was cancelled because it was outdated. The laser was a gas dynamic design (basically a rocket engine which is why Pratt and Whitney and Rocketdyne was in the business). Getting the laser to activate was nightmare of pumps, valves, and plumbing and the beam quality was horrible. None of that mattered for the purpose of feasibility demonstration but it was not the way to go forward. The ALL did have deformable mirrors. As with all the mirrors (except the beam director), the mirrors were metal (molybdenum for stiffness/heat transfer) and were a brazed assembly with lots of cooling channels running through them.

The intent was to build ALL 2. This was a 747 with a Deuterium Fluoride chemical laser 4 times more powerful and a much bigger beam director. As usual, the cancellation was not followed with the replacement. In any event, chemical lasers gave way to COIL lasers and ABL came about. This book provides the official Air Force history of the program.

https://www.amazon.com/Airborne-Laser-Robert-W-Duffner/dp/0306456222

 

[KJ_Lesnick]

So, if the laser didn't activate as easily as desired means that, while they successfully zapped a couple of AIM-9's, they might very well have either have had no firings in some cases?

 

[fredymac]

It meant you needed to have the system up and ready before the launch. The only thing you didn't do was flow the chemicals but you had all the hardware activated and functional. The big thing about solid state lasers is that you can turn them on and off easily and leave them on for extended times (no chemical tanks to worry about). Solid state lasers still can't reach the power levels of chemical lasers but perhaps another 5 years they may start getting there. Free electron lasers are still the best for extreme power but the US seems to have shut down further work on them.