Re:SpaceX launches first U.S. national security space mission
by pilsetnieks on Monday December 24, 2018 @06:34PM
(#18754894)
Ion engines still need propellant, you might be thinking of the so far unproven EM drive.
Looks like they use a liquid fuel thruster lift it to its final orbit[0]. Some other missions have used ion engines for orbit raising[1]. I wonder why that wasn't incorporated into the GPS design.
[0] https://en.wikipedia.org/wiki/Lockheed_Martin_A2100 [1] https://space.skyrocket.de/doc_sdat/ses-12.htm