This page explains main subsystems of Misasa Deep Space Station.

Overall Antenna Telecom LNA Time and Frequency Signal Generator Open-loop Multi-band Receiver Others

Overall Overview

The subsystem configuration of Misasa Deep Space Station is as follows, and the main subsystems are Antenna, Telecom, X-band LNA, Ka-band LNA, Time and Frequency Signal Generator, and Open-loop Multi-band Receiver.

Responsive image

Antenna Subsystem

Antenna Subsystem gathers radio waves from noise spacecrafts from as much as possible. MDSS can receive not only X-band but also Ka-band.
Responsive image

Responsive image



Vertical: 54026.4mm
Side: 54027.6m at an elevation angle of 15 degrees

Drive range


Antenna drive machine

  • Mounting method: Az-El
  • Drive method: The anti-backlash mechanism
  • Maximum drive speed: Az:1.0016deg/sec, EL:1.0016deg/sec
  • Drive control: less than 0.1mdeg
  • Drive mode:
    X-band: program tracking
    Ka-band: program tracking, auto tracking
  • Scan method: angle offset, 5 points method, cross elevation and cross direction
  • Auto tracking accuracy: 1.5mdegrms
  • Drivable wind speed: over 30m/sec
  • Survival wind speed unbreakable wind speed: over 65m/sec


X-band: 54.69dB/K@EL=15deg
Ka-band: 60.97dB/K@EL=15deg

Antenna gain

X-band(UPLINK): 69.62 dBi
X-band(DOWNLINK): 72.59 dBi@EL=15deg
Ka-band(DOWNLINK): 83.26 dBi@EL=15deg

Design life

Over 20 years


2240tons Approx.

See the User's guide for more details.

Telecom Subsystem

The telecom subsystem includes many components. Most of them are placed inside the alidade building. The telecom subsystem has the following functions.

Responsive image

Responsive image


Uplink Frequency


Downlink Frequency

X-band: 8400-8500MHz
Ka-band: 31800-32300MHz

Supported polarization


Modulation type


See the User's guide for more details.

Low Noise Amplifier (LNA)

Low Noise Amplifier (LNA) expands signals gathered by antenna and transmits them to the Telecom subsystem.
X-band LNA consists of the low noise amplification unit, the remote control monitoring unit, the refrigerator compressor and the turbomolecular vacuum pump. In order to achieve the required performance and the input equivalent noise temperature of less than 21K, the cooling amplifier of the low noise amplifier is cooled to the cryogenic temperature of -269°C (4K).
JAXA has manufactured and installed the first Ka-LNA for deep space exploration in Japan by JAXA in-house. The Ka-LNA uses a GM (Gifford-McMahon) refrigerator with gaseous helium for cryogenic cooling to reduce noise. X-LNA uses the same method, and the equipment of X-LNA and Ka-LNA are shared.
Responsive image

X-band Low Noise Amplifier
Responsive image

Ka-band Low Noise Amplifier (by JAXA in-house)
Responsive image
See the User's guide for more details.

Time and Frequency Signal Generator

Responsive image

Open-loop Malti-band Receiver

Responsive image

Other equipments

  1. GNSS receiver
  2. It is a monitor station for the Quasi-Zenith Satellite System and is expected to be a very useful observation station in the international positioning field because it colocates with the 54m antenna (VLBI observation station).
    The acquired observation data is provided to the IGS (International GNSS Service) on a daily basis and utilized worldwide. This station is registered with the IGS as ID: MSSA00JPN.

    Responsive image

  3. Radio seeing monitor
  4. When radio waves pass through the earth's atmosphere, phase fluctuations called "radio seeing" occur. When the frequency is low, the radio seeing of the electron density in the ionosphere is the main factor. On the other hand, the higher the frequency, the more the water vapor density in the troposphere becomes the main factor. Large antennas such as MDSS, which handle high frequencies, are greatly affected during observation, so a radio seeing monitor device is installed to constantly monitor them.

    Responsive image

  5. Water vapor radiometer
  6. At high frequencies, the amount of water vapor in the atmosphere affects the amount of radio wave attenuation, so a water vapor radiometer constantly monitors the state of water vapor in the atmosphere.

    Responsive image