I wonder if modern heat seeking missiles would even lock on to a J3?
Especially when you have 10 minutes. That's not a long time, especially when some of that time will be spent evaluating the thread and deploying defenses.
Imagine a J3 diving with the engine off how would you shoot it down?
Would a stinger type weapon be able to lock on to a stopped J3 engine?
Small arms fire is probably not going to do it.
You can poke a lot of holes in a J3 and unless you hit the main wing beam it might keep on its ballistic course. I suppose a 20 mm round on the engine or the explosive payload would take care of it, but how hard would that be to accomplish?
I hope the USSS has already figured this out.