The last third generation Tracking and Data Relay Satellite (TDRS) has finally joined the remaining nine in a geosynchronous fleet. Initially called the TDRS-M, and later renamed the TDRS-13, it was launched in August of 2017. It was built in California by Boeing and has a design that is nearly identical to the other two produced by the same company. Now that it has joined the others, the entire space-fleet is full and can continue to monitor and relay data until at least 2020.

TDRS satellites are vital in the operation of NASA missions, as they are the source of communication and navigation. The project began in 1973 with the first TDRS satellite being launched just a decade later. NASA was able to dramatically increase contact time and data rates when communicating with spacecraft in orbit. Based on this success, they continued developing the program, expanding the network and advancing its capabilities.

The so-called Space Network, or constellation consisting of ten TDRS satellites, orbits 22,300 miles above Earth. This arrangement gives NASA researchers and scientists on the ground near-instantaneous access to communications with crafts and satellites such as the Hubble Telescope and the International Space Station. Currently, the network can facilitate communication between astronauts and ground control, as long as they are not higher than 250 miles above earth.

NASA isn’t abandoning tracking or data/signal relay. Instead, they are focusing on designing next-generation crafts, capable of longer range monitoring. Deputy associate administrator for Space Communications Badri Younes said that NASA recognizes the increased reliance almost all communications have on commercial networks. In addition, satellites need to be capable of receiving and relaying data over further distances. As a result, they are planning to develop new and improved ways to meet those long-term communication needs.