Scientist John Bonnell and (later in the movie) engineer Bill Donakowski help with a test of how the electric field instrument (EFI) boom that is located on the spin axis (axial boom) expands. See the axial boom deployment movie for a close-up of this boom deployment. In this movie, the test takes place in a clean room and at a time when the EFI axial boom is on the satellite with the other instruments. There are engineers outside the clean room helping with the test, talking about when the test is successful. When you hear a “click,” this indicates that one of the axial booms has been deployed. The second click is associated with the second axial boom.