Japan’s QZSS constellation to receive replacement satellite

July 20, 2021  - By

The successor to the first quasi-zenith satellite, dubbed Michibiki, is expected to launch this year.

Michibiki was launched by the Japan Aerospace Exploration Agency (JAXA) in September 2010 and was transferred to the Cabinet Office in 2017. The replacement satellite is now undergoing prototype testing at the satellite manufacturer’s facility  (Mitsubishi Electric Co. Ltd. Kamakura Seisakusho) in Kanagawa. 

The tests will confirm performance of the replacement satellite before it is put into service. It is undergoing acousitic, vibration and thermal vacuum tests to ensure it will remain functional after launch and in space. 

After testing, the satellite will be transported to the Tanegashima Space Center for launch, which is expected to take place later this year.

Replacement for Michibiki: The L-band antenna that transmits the positioning signal is mounted on the Earth-oriented left side. (Photo: JAXA)

Replacement for Michibiki: The L-band antenna that transmits the positioning signal is mounted on the Earth-oriented left side. (Photo: JAXA)

Though built to succeed the first QZSS satellite, the replacement is based on the second and fourth satellites

Main specifications of the successor to the first satellite and other satellites:

item First machine Units 2 and 4 Unit 3 Successor to the first machine
Orbit Quasi-zenith Quasi-zenith Rest Quasi-zenith
Positioning signal L1-C / A,
L1C, L1S,
L2C, L5, L6
L1-C / A, L1C,
L1S, L2C,
L5, L5S, L6
L1-C / A, L1C,
L1S, L1Sb, L2C,
L5, L5S, L6
L1-C / A
(L1-C / B (* 1)),
L1C, L1S, L2C,
L5, L5S, L6
L band antenna Helical method
(* 2)
Helical method
(* 2)
Patch method
(* 3)
Patch method
(* 3)
Generated power 5.3kW 6.3kW 6.3kW 6.3kW
mass About 4t About 4t About 4.7t About 4t
Design life 10 years or more Over 15 years Over 15 years Over 15 years
Launch year 2010 2017 2017 2021
(planned)
Launch
rocket
H2A202 H2A202 H2A204 H2A202
(* 1) Signal transmitted by BOC (Binary Offset Carrier) modulation of L1-C / A code
(* 2) Antenna with spiral antenna elements arranged
(* 3) Antenna with planar antenna elements arranged

.

 

About the Author: Tracy Cozzens

Senior Editor Tracy Cozzens joined GPS World magazine in 2006. She also is editor of GPS World’s newsletters and the sister website Geospatial Solutions. She has worked in government, for non-profits, and in corporate communications, editing a variety of publications for audiences ranging from federal government contractors to teachers.