The Jupiter Magnetospheric Orbiter (木星磁気圏オービター, JMO) is a cancelled space probe proposed by the Japanese Aerospace Exploration Agency (JAXA), to undertake detailed in situ studies of the magnetosphere of Jupiter as a template for an astrophysical magnetised disk.
The JMO was originally proposed in 2006 as the Japanese contribution to the now cancelled Europa Jupiter System Mission (EJSM).
[3][4][5] However, the EJSM collaboration was disbanded and NASA renamed its initiative with Europa Multiple-Flyby Mission, ESA's Jupiter Icy Moon Explorer, and Roscosmos's Laplace-P.
The size and weight of the JMO would have been limited to carry a payload up to 10 kg, equivalent to 2 to 3 scientific instruments.
In order to conduct observations never made before, the spacecraft would have carried an X-ray imaging spectroscope, featuring different wavelengths from instruments onboard NASA's Juno probe.