As shown in the book/movie, each mission had its own gear capable of communicating with Earth, which seems redundant, yet still only be able to do so while the Earth is above the horizon.
However, why not have the first mission include a small constellation of communications satellites? That way, all later missions would only need much cheaper/lighter gear to reach a comsat, one of which would always be above the horizon and one of which would always be able to reach Earth.
In fact, the short-range gear to communicate with the comsats should be no more than a satphone, which means it should be light/cheap enough to put into every suit, rover, probe, etc. and have vastly increased capabilities and safety.
I know sending stuff to Mars isn't cheap, but if you are sending multiple manned missions, then the economics change dramatically. Putting long-range com gear in Mars orbit once seems a lot cheaper than safely landing it on the surface multiple times.