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Solar Wind Ion Mass Spectrometer (SWIMS) and Solar Wind Ion Composition Spectrometer (SWICS): These two instruments are time-of-flight mass spectrometers, each tuned for a different set of measurements. They analyze the chemical and isotopic composition of solar wind and interstellar matter.
Ultra-Low Energy Isotope Spectrometer (ULEIS)
ULEIS measures ion flux and is sensitive to a range from helium through nickel to determine the makeup of solar energetic particles and the mechanism by which the particles become charged by the sun.
Solar Energetic Particle Ionic Charge Analyzer (SEPICA)
As of 2008, this instrument is no longer functioning due to failed gas valves.
Payloads are separated by bullets ( · ), launches by pipes ( | ). Manned flights are indicated in bold text. Uncatalogued launch failures are listed in italics. Payloads deployed from other spacecraft are denoted in brackets.