Vehicle: Airplane: Security
Cold Cloak   (+1, -1)  [vote for, against]
The trail has gone cold...

Passenger jets should have tanks of liquid nitrogen that they can spray out the back and cloke the plane from a heat seeking missle. Would only be required during takeoff and landing, & much safer than letting off flares over an urban area.
-- simonj, Aug 14 2003

Passenger jets should have tanks of liquid nitrogen just for the passengers to play with. That stuff is rad.
-- DeathNinja, Aug 15 2003

I'd like a cold Cloke, please. With ice.
-- Cedar Park, Aug 15 2003

//liquid nitrogen just for the passengers//

"For persons wishing to play with our in-flight liquid nitrogen, there will be a $4.00 fee for the storage dewar."
-- Amos Kito, Aug 15 2003

It's not a bad idea. I'm not sure that you could get enough into the atmosphere to adequeately mask the heat signature of a lumbering large craft like a passenger jet, though.

I have had the fortune to play with a few liters of liquid nitrogen and found it to be a really interesting thing. Freezing bananas and shattering them, etc.

Food stylists use it to make the food "steam" in food shots for commercials and film.
-- bristolz, Aug 15 2003

What to do if the heat seeking missle approaches from the front?
-- kbecker, Aug 15 2003

I don't think there'd be much of a thermal profile, approaching from the front. You could always have the LN exhaust from the nose of the craft, enveloping it. For something like this I don't think visibility is too much an issue.
-- phoenix, Aug 16 2003

Yeah, you'll forget about the missle as your plane flies through it's own cloud of liquid nitrogen and shatters
-- BikBear, May 06 2004

Extrapolating from what i know of stealth planes, it is not the hot air that is targeted by warheads, but the hot parts of the exhaust. Those are usually hid from 'view', to complicate the target acquisition, while cold air is brought in from the sides to mix with the exhaust and hinder the heating of the elements doing the hiding. Thus, a system as you propose would need to cool parts of the plane, which might be stressful for the material.
-- loonquawl, May 27 2009

random, halfbakery