Why does the InSight Mars lander mission intend to launch from Vandenberg, which does not allow for prograde launches? Will it launch into polar or retrograde orbit? Why? It will do an interplanetary transfer, so would the best orbit not be around the ecliptic, so about 23.5º and prograde, because it saves fuel?
I googled around for a bit and the only thing I found was, that it is the first interplanetary launch from Vandenberg, which totally makes sense to me, because why would you launch those from there.