Why didn't the U-2 spyplane have any chaff? The U-2 spyplane was shot down over Russia in 1960 and over Cuba in 1962, both times by a radar-tracking missile. Why wasn't it equipped with any chaff to throw off the missile?

Chaff is just a cloud of aluminum particles that return a big radar blur, masking the real craft so it can get away. The missile would home in on the chaff instead since it's a big juicy radar target. Chaff can be stored in very small cylinders near the tail of the plane, and the radar lock warning would let the pilot use it at the right time.

Chaff was invented in World War 2, giving plenty of time all the way to the sixties. So why wasn't this airplane equipped with chaff?
There are two main reasons for this:


USAF and CIA believed that the Russians (or anyone else) wouldn't be able to shoot down aircraft operating at (>60000ft).
Most of the aircraft operating during that time did not have chaff dispensers to deploy chaff as needed. For that to work, the pilot has to either visually acquire the missile or have a RWR, which became widely used only in the later stages of Vietnam War.


Another important reason is tactics. The chaff was not used in WWII in a tactical capacity i.e. to protect individual fighters, but to provide blanket coverage to bomber fleets. This practice continued well into the Vietnam War. For example, specialized aircraft (usually fighters) will dump chaff to provide a 'corridor' for following bombers. For an aircraft on reconnaissance mission, this is as good as advertising its presence. 

A lot of aircraft in that era went without any countermeasures. For example, the English Electric Lightning carried no chaffs till its retirement in 80's.