"Beep beep beep beep," said Leonard Nimoy, imitating his favourite piece of space hardware. But what is one voice in the vast night sky? You want yourself a satellite network, Len my son. That's the focus of update 1.2 for Kerbal Space Program [official site], which launched last night. It lets players link satellites and other hardware to bounce and boost signals all over, and also use satellites to map terrain. Oh, and the update makes your wheeled vehicles and flying vehicles more stable, less prone to wonky physics explosions - unless that's what you really want, of course.
The full changelog for the 'Loud and Clear' update 1.2 is over here. It explains things like communications networks:
"Additional functionality and gameplay components to the Antenna and Probe parts through a series of distinct but related mechanics. When CommNet is enabled, probes will require a connection back to Kerbin or to a control point to have full control, and crewed vessels lacking pilots will have slightly limited control without such a connection. Relays can extend the range of such connections and bounce signals around planets and moons that would otherwise occlude. Science transmission receives a bonus for high signal strength. New antenna parts allow building complex networks, which can be visualized in map view."
* Added KerbNet, which allows the player to see terrain under their satellite, and place custom waypoints with a targeting interface. Allows the player to see biomes and anomalies at higher levels. Scan field of view for KerbNet varies by part and smoothly changes between surface altitude and orbital altitude.
* KerbNet allows all probes and labs manned by a scientist to map as long as they have a communications network connection that eventually bounces to Kerbin.
If you want the patch notes in a more easily-digestible format, here's a trailer with an overview: