QZS-5: Difference between revisions – Wikipedia

QZS-5 (Michibiki No.5) is a Japanese navigation satellite consisting part of the Quasi-Zenith Satellite System (QZSS). QZS-5 will be deployed to a quasi-zenith orbit (QZO). With the launch of QZS-5, QZS-6, and QZS-7, the QZSS will expand from a GNSS augmentation service to a independent regional navigation satellite system (RNSS) covering the Asia-Pacific region.

QZS-5 is the second of three Michibiki satellites to be launched to expand QZSS to a seven-satellite constellation. In 2017, Michibiki’s four-satellite constellation established, and with it there are at a minimum two Michibiki satellites (one in QZO and one in GEO) constantly visible from Japan. Satellite navigation requires at least four satellites to be visible, so users need to receive signals from QZSS and other global navigation satellite system (GNSS) at the same time.^[3] In its seven-satellite constellation, four Michibiki satellites (one in QZO, two in GEO, and one in quasi-geostationary orbit (QGEO)) will be constantly visible from Japan, thus eliminating the system’s dependancy on other GNSS. QZS-5 will join QZS-2 and 4, QZS-1R in Quasi Zenith Orbit.

QZS-5 was manufactured by Mitsubishi Electric (MELCO), and its positioning mission payload was manufactured by NEC.^[4] QZS-5 has a design life of 15 years.^[2] Like QZS-6 and QZS-7, the satellite has a Precise Ranging Payload (PRP) consisting of Inter-satellite ranging (ISR) and satellite/ground bi-directional ranging. PRP enables the satellite to achieve a precise positioning measurment compared to previous Michibiki satellites. The Japan Aerospace Exploration Agency‘s Advanced Satellite Navigation System (ASNAV) project is responsible for Michibiki’s PRP.^[5] For ISR QZS-5 will be the source of the signals. QZS-6 and QZS-7 meanwhile will receive QZS-5’s signal to measure the distance between them.^[6]

QZS-5 is planned to be launched in December 2025.