The missions' first four delays were to allow for additional time for checkouts and processing on the Falcon 9 rocket they'll ride to space, according to NASA. Now, the delay is "due to the availability of a launch opportunity on the Western range," NASA said in an update.

NASA and SpaceX are preparing to launch a first-of-its-kind mission to study the powerful electric currents that surge through Earth’s atmosphere during aurora displays. These“auroral electrojets” push millions of amps of electrical charge around the planet’s poles every second,

Scientists have been wondering about auroral electrojets for a long time. This mission could change how we understand them.