core dump: does anyone know what the 3rd parachute is for? "Equipment" can mean a lot of things. If it's something top secret, I'm not sure I'd want it dangling from a canopy for all to see the landing location
Most ejection systems/seats have a smaller drogue parachute that is sometimes thought to be another chute or crew member by (often unreliable) eyewitnesses. As this was a training version of the U-2, it would not have the most sensitive of equipment on board.
All the best to those and the families involved.