Yet, compared to some other potential implementations of a coilgun launcher with relatively higher requirements for pulse power switching devices (an example being an escape velocity design of 7 kilometers length after a 1977 NASA Ames study determined how to survive atmospheric passage from ground launch), L5 News, Sept 1980: Mass Driver Update which are not always semiconductor-based, the 130-km acceleration tube length of Gen-1 spreads out energy input requirements over a longer acceleration duration.