Launched in the summer of 2000, Cluster II was part of the Solar Terrestrial Science Programme Cornerstone (together with SOHO) of ESA's Horizon 2000 programme. The quartet of Cluster spacecraft orbited the Earth exploring the magnetosphere and solar wind close to Earth. The mission was brought to a close on September 8th 2024 when the Salsa spacecraft became the first of the four to re-enter the atmosphere.
Each Cluster spacecraft carried a suite of instruments to study the waves, fields and particles in the magnetosphere. Part of that suite was the PEACE (Plasma Electron And Current Experiment) instrument. Two PEACE sensors on each spacecraft measured the 3D velocity distributions of the electrons that make up part of the space plasma surrounding the Earth.
The PEACE instrument was designed and built by MSSL. MSSL are responsible for the operation of the instruments and the processing and calibration of the raw instrument data. These data are then delivered to the Cluster Active Archive to enable scientists from around the world to participate in the analysis of Cluster data. Prof. Andrew Fazakerley is the instrument's Principal Investigator.
PEACE is one part of a family of particle detectors developed for investigating a range of space plasmas. Instruments based on the heritage of PEACE have been flown on the Cassini and spacecraft and are currently flying onboard the Solar Orbiter spacecraft.
The Cluster II Mission
The Cluster II mission, together with the Solar and Heliospheric Observatory (SOHO), forms the First Cornerstone of ESA's Horizon 2000 programme.
The PEACE Instrument
PEACE is a top-hat electrostatic electron analyser. It is designed to measure the 3D electron velocity distribution in the energy range 0.7 eV to 32 keV in the vicinity of the Cluster spacecraft.
PEACE Publications
Details of publications using data from the PEACE instruments onboard Cluster II
Mission Concept
The Cluster concept was to fly four well instrumented space plasma research spacecraft in formation, which will typically be tetrahedral for as long as orbital mechanics permit.
PEACE Data Access
PEACE data and Quicklook plots are freely available online.
Cluster: End of Mission
After 24 years of successful operations, the Cluster mission finally ended on September 8th 2024 when the SALSA spacecraft re-entered Earth's atmosphere
MSSL Cluster II contacts
