TDRS
NASA relay satellite network linking spacecraft to Mission Control.
Last refreshed: 3 April 2026
What happens to astronaut communications when Orion flies beyond the relay satellites reach?
Latest on TDRS
- What is the TDRS satellite system?
- A constellation of NASA relay satellites providing near-continuous communication between spacecraft and Mission Control since 1983.Source: NASA
- How does Artemis II communicate with Earth?
- TDRS handles communication near Earth; the Deep Space Network takes over as Orion moves beyond geosynchronous orbit toward the Moon.Source: NASA
- Is the TDRS constellation being replaced?
- Several satellites have exceeded their design life. NASA is debating replacement timelines against commercial alternatives.Source: NASA
Background
The Tracking and Data Relay Satellite System (TDRSS) is a constellation of geosynchronous communication satellites operated by NASA to provide near-continuous contact between Mission Control in Houston and spacecraft in orbit or beyond. Before TDRS, NASA relied on a chain of ground stations that left spacecraft out of contact for large portions of each orbit. The first TDRS satellite launched in 1983; the current constellation provides coverage across most of low Earth orbit and deep space transit corridors.
For Artemis II, TDRS handles the critical communication relay during Earth-proximity phases of the mission, passing voice, telemetry, and commanding data between Orion and Houston. As the spacecraft moves beyond geosynchronous orbit toward the Moon, communication transitions to the Deep Space Network (DSN). The handoff point is operationally significant: TDRS provides higher bandwidth and lower latency than DSN, meaning crew communication quality degrades as they move further from Earth.
The constellation is ageing. Several satellites have exceeded their design life, and NASA has debated replacement timelines against commercial alternatives. For Artemis II, TDRS availability during launch and trans-lunar injection is a mission constraint that flight planners must account for in launch window calculations.