Tracking and Communications Center’s Domestic Stations

Usuda Deep Space Center in Nagano Prefecture

The Usuda Deep Space Center was constructed to transmit operational commands to deep-space probes that approach and observe astronomical bodies such as comets, planets and asteroids, and receive the observation data from the probes. This site was selected in order to receive the weak signals from probes in deep space. The distance is so immense that there needed to be very low radio wave interference and other such noise common to a city. This Center opened in October 1984. The large parabolic antenna as the core of the facility has a reflecting mirror with a diameter of 64m and the total weight is 2,000 tons. Communications with spacecrafts are performed using band S (2GHz) and band X (8GHz). The US (NASA), Russia, ESA, China and India own antennas designed for the same purpose. Previously, the parabolic antenna with a diameter of 10m was used to obtain the VLBI (Very Long Baseline Interferometry) observation data from the Radio Astronomical Satellite “HALCA” that orbits the earth. Now however, it is used for various experiments for VLBI or high-speed data transmission. The antenna with a diameter of 64m is used for spacecraft high precision orbit determination using VLBI technology, and also high precision antenna position land survey and astronomical observation.

Misasa Deep Space Station (Nagano Prefecture)

Misasa Deep Space Station (MDSS) is a large antenna facility located in Saku City, Nagano Prefecture. Featuring a 54-meter parabolic antenna, it was constructed as part of the Usuda Deep Space Center to support the operation of spacecraft travelling through deep space – regions more than two million kilometers from Earth.

MDSS was completed in March 2021 and begun full-scale operations in April of the same year. By March 2024, the facility underwent major upgrades to improve reliability and operational flexibility, enabling it to better support international missions. To ensure steady support for future deep space exploration, the station now uses Ka-band, first introduced during the Hayabusa2 mission. It is also being prepared to handle the large volumes of data expected from upcoming lunar and Lagrange point missions, while strengthening global collaboration in space activities.