NASA WING | Spring Lightbulb Drop Tower Experiment 

This drop tower experiment was a part of What If No Gravity? (WING). WING is a NASA educational program for teams of students to design and build an experiment to be tested in a NASA microgravity drop tower.
In the beginning, gravity causes the hanging springs to expand towards the ground. In microgravity, the springs recoil. Because of the module's design, the recoiling springs cause the lightbulb to turn on.