Cassini Ion Neutral Mass Spectrometer (INMS)
The Cassini Ion and Neutral Gas Mass Spectrometer (INMS) was designed, constructed, calibrated and
tested at Goddard Space Flight Center (H. Niemann, Instrument Development Task Manager). The
quadrupole mass spectrometer instrument has been described in Kasprzak et al. (1996) and Waite et
al. (2004). It was supplied to the NASA Cassini project as a facility instrument.
After launch, instrument operations, data processing/analysis and science interpretation have been
accomplished by a NASA facility team. The facility Team Leader is J. H. Waite, Jr (Southwest
Research Institute). The Team Members are T. E. Cravens (University of Kansas), W.-H. Ip (North
Central University, Taiwan), W.T. Kasprzak (NASA Goddard Spaceflight Center), J. G. Luhmann
(University of California, Berkeley), R. L. Mc Nutt, Jr. (John Hopkins University) and R. Yelle
(University of Arizona). This original core team and its adjunct members constitute the larger INMS
Since orbit insertion around Saturn on July 4, 2004, the instrument has obtained in-situ measurements
of low energy positive ions and neutral gas in Titan's upper atmosphere, and in the environments of the
icy satellites, rings and the inner magnetosphere of Saturn, wherever densities are above the measurement
threshold and ion energies are below about 100 eV.