NASA has satellites in GEO called TDRS, Tracking and Data Relay Satellites, which relay commands and telemetry from LEO satellites. Prior to TDRS, astronauts could communicate with the Earth for only about 15% of the orbit, using 14 NASA ground stations around the world. With TDRS, coverage of low-altitude satellites is global, from a single ground station at White Sands, New Mexico.
The introduction of NASA's TDRS system has enabled global communication with low Earth orbit satellites, previously limited to only about 15% of the orbital period. This improvement in communication capabilities relies on a single ground station at White Sands, New Mexico, rather than the 14 stations used prior to TDRS.