U.S. Air Force has shot down multiple air-launched missiles in a test

Re:U.S. Air Force has shot down multiple air-launched missil... by Symmetry on Tuesday May 07, 2019 @09:32AM (#19849121)

An ablative shield will would help protect a missile from a laser burning through it but it won't protect form the shock wave caused by the rapid heating of the missile surface. I'm not actually sure which of those is the important mechanism in this case.

But more importantly I'm not sure how you can have one and still have a missile guidance system on board, and also they tend to be pretty heavy.

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Re:U.S. Air Force has shot down multiple air-launched missil... by wnkrshm on Tuesday May 07, 2019 @11:31AM (#19850439)

I don't know anything about mechanical shock waves due to rapid heating in the material but in terms of the weight of an additional heat shields and their effectiveness I've found this:

AVCOAT 5026-39 which apparently is an ablative heat-shield material for NASA's Orion (and has been developed during the Apollo years) has a density of 0.51g/cm³ so about half the density of water and one fifth that of aluminum (of which a guided missile is made mostly, I believe).

From reading some reports of the performance of Apollo era heat shields it's clear though that reentry is a way more gentle affair in terms of thermal load, than a 50kW laser in a 1cm2 spot.

The endured peak heat flux per area is about 0,48 kW/cm2 for the heat shield, magnitudes off, if the 50kW laser can achieve a 1cm2 spot.

The total amount of heat flux the ablator was required to endure results in a total amount of heat energy/area of 0,0141 kWh/cm2 - which 50kW in a 1cm2 spot would saturate in about 1 second. Reentry lasted 800-1000 seconds.

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Re:U.S. Air Force has shot down multiple air-launched missil... by quakeguy on Tuesday May 07, 2019 @12:12PM (#19850828)

Just rotate the missile in its trajectory? Even ablation and guidance is still possible... -another arm chair general-

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