Japan’s QZSS constellation to receive replacement satellite
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)
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
.