reply to post by Dr Love
The simple answer is that we already have "backward firing missiles" - or, at least, missiles that can acquire a target behind the firing
This is accomplished through "datalinking" - networking, essentially. Coarse coordinates can be delivered from any networked source that can
deliver a valid track. Theoretically, this can be almost anything - the RWR from the firing aircraft, the AWACS supporting the firing aircraft, the
aircraft's wingman (an IR, radar, or optically derived track), satellites, even other missiles and ordnance with sufficient uplink capacity.
It's not necessary to guide the missile into the target - it has its own onboard seeker and guidance system for that. All it needs to do is know how
to position itself so it can pick up the target with that seeker, and any information that will help it isolate that as the target (helps to avoid
being spoofed by chaff/flares/etc).
In this respect, it doesn't matter where the target is in relation to the firing - or targeting - aircraft. An electronic support aircraft can be
'spiked' by a tracking radar, completely unarmed. An escort aircraft - even if it is currently engaged - can fire a missile on the aircraft (or
ground target) illuminating the electronic support aircraft. The only real factor is the kinetic factors of the firing aircraft and how that will
impact the kinetic performance of the missile being fired (firing a missile forward makes it go farther than making it have to turn around and fly
backwards relative to the firing aircraft).
One of the things being done, now, with loiter aircraft like the B-52 is having them fly a high-orbit above a conflict area. At some hierarchical
level, ground troops are assigned laser designators with uplinks to the same network the bomber is on. When they run into more difficult targets,
they can place a request to have a "bomb on demand" delivered from that bomber.
Not exactly missiles being fired backwards - but to similar ends - something behind you that you need blown up being blown up.
The only other thing I can think of is some mention -in fictional novels (Dale Brown) - mentioning "air mines" deployed from the back of large
aircraft (such as the fictional EB-52 "Megafortress" and the EB-1 "Vampire" ) - explosive canisters of shrapnel launched behind the aircraft and
into the path of a close-trailing hostile. A sort of hybrid between a missile and the old .50 cal tail-guns.
I'm not sure if such a thing has been tested to the prototype phase, or has simply stayed on papers and laboratories. I'm not aware of anything
actually employing such a system, however.