Re:"trapped"? (Score 1)

I'd assume it goes something like this:

1. U2 spyplane is flying through the stratosphere more or less horizontally.
2. Space dust is falling through the stratosphere more or less vertically.
3. Paths of plane and space dust intersect.
4. Space dust particles, being in general much smaller than a U2 spyplane*, stick to the plane rather than the other way around.

*) If the dust particles are large enough, however, it is possible for the plane, or at least pieces of it, to stick to the particle as it plummets towards the Earth. Space dust particles of such size are usually called meteors, and their encounters with high-altitude spyplanes are usually referred to as "shit happens".