Spacecraft --- Space Shuttle --- Communication

Astronauts must be able to talk with flight controllers on the ground daily for the routine operation of the mission. Moreover, they must be able to communicate with each other inside the orbiter or its payload modules and when conducting spacewalks outside.

Talking with the Ground
NASA's Mission Control in Houston will send signals to an antenna at White Sands Test Facility in New Mexico. White Sands will relay the signals to a pair of Tracking and Data Relay satellites in orbit 22,300 miles above the Earth. The signals will be relayed by the satellites to the the space shuttle, vice versa.
The orbiter has two systems for communicating with the ground:
S-band - voice, commands, telemetry and data files
Ku-band (high bandwidth) - video and transferring two-way data files

Talking to Each Other
The orbiter has several intercom plug-in audio terminal units located throughout the crew compartment.
The communications control is battery-powered and can be switched from intercom to transmit functions. Astronauts can either push to talk and release to listen or have a continuously open communication line.
To talk with spacewalkers, the system uses a Ultra High Frequency (UHF), which is picked up in the astronaut's spacesuit, which is described in section Spacesuits.

Basic Structure and Launching Position and Orbit Communication Navigation Power Computer Returning to Earth