Flux capacitor

The Flux capacitor was the key component for time travel and thus the major enabler for the DeLorean time machine and Jules Verne Train.

History
Invented by Dr. Emmett Brown by accident in 1955, the flux capacitor was first utilized in the year 1985 for the first temporal displacement. It initially required plutonium and a miniaturized nuclear reactor while the vehicle it was attached to attained 88 miles per hour in order to generate the 1.21 gigowatts required for time travel.|Back to the Future

When Emmett Brown visited the year 2015 the plutonium was no longer required and the flux capacitor now utilized the energy extracted by the removal of hydrogen atoms from garbage via the Mr. Fusion Reactor. |Back to the Future, Part II

When Doctor Brown encountered the stranded USS Voyager away team he requested their help in rescuing Marty McFly and recovering the flux capacitor which Marty had hidden to prevent the technology from falling into the hands of Biff Tannen and Armus.