The uplink transmitters of the Deep Space Network (DSN) perform three key functions in support of space missions: navigation, command uplink, and emergency recovery. The transmitters range in frequency from S‐band to Ka‐band, and range in RF transmit power from 200W to 400kW. Future improvements to the uplink transmitters will focus on higher frequency transmitters for high data rate communications, high power X‐band uplinks for emergency recovery, and/or in‐phase uplink arraying for either application. © 2003 American Institute of Physics