A Plasma Electron And
Current Experiment instrument can measure the three dimensional
velocity distribution of electrons in a space plasma, for an energy range from
a few electronvolts to about 30 kiloelectronvolts. A PEACE instrument is flying
on each of the four Cluster II spacecraft, which were launched in the summer
of 2000. The science phase of the mission officially started in February 2001.
The mission is now usually referred to as Cluster rather than Cluster II. MSSL
is the PI Institution for the PEACE instruments.