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Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA)

NSSDCA ID: 2004-006A-09

Mission Name: Rosetta
Principal Investigator:Prof. Kathrin Altwegg


The Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA) instrument consists of three sensors, a double focusing magnetic mass spectrometer, a reflectron time-of-flight mass spectrometer, and a neutral and ion dynamics monitor. The primary scientific objectives for the experiment are to: 1) determine the elemental, isotopic molecular composition of cometary atmosphere and ionosphere; 2) measure bulk velocities of neutral and ionized components; 3) study homogeneous and inhomogeneous reactions of neutrals and ions in dusty cometary atmosphere and ionosphere; and 4) investigate possible asteroid outgassing.

The double focusing magnetic mass spectrometer (DFMS) has a mass range of 12 - 100 amu with a resolution m/delta-m of 3000 at 1% peak height. The instrument consists of two entrance apertures, one with a 20 x 20 degree field of view and one 2 x 2 degrees, a set of magnetized deflection plates, an electrostatic zoom system, and an analyzer and mass detector. The instrument is sealed under vacuum before launch. A protective cap is removed from the ion source aperture during the cruise to the comet, at which time the analyzer section vent will also be opened. The DFMS can be switched between two operating modes, a cometary gas mode and a cometary ion mode.

The reflectron time-of-flight spectrometer (RTOF) consists of two similar but independent source-detector systems, one for cometary ions and one for cometary neutrals. The instrument consists of ion sources, ion optics, a reflector, and the detectors. Neutral gas which enters the gas inlet is ionized and stored, then sent by the ion optics via deflection plates to the reflectron which focuses the ions back to two separate detectors, each consisting of an anode, microchannel plate, and grid. Ions entering the ion inlet are pulsed through the optics to the same reflectron and focused back to the same detectors. The RTOF measures in a mass range from 1 to >300 amu with a mass resolution of 500 at 1%.

The neutral and ion dynamics monitor (NIDM) consists of three pressure gauges to make velocity in the range Mach 0.5 to 4 and temperature measurements in the range 50 to 500 K of the cometary gas. An ion dynamics sensor may also be included.

Alternate Names

  • Rosetta/ROSINA
  • urn:esa:psa:context:instrument:ro.rosina


  • Planetary Science: Small Bodies

Additional Information

Questions and comments about this experiment can be directed to: Dr. David R. Williams



NameRoleOriginal AffiliationE-mail
Prof. Kathrin AltweggPrincipal InvestigatorUniversitat

Selected References

  • Balsiger, H., et al., Rosetta Orbiter Spectrometer for ion and neutral analysis-ROSINA, Adv. Space Res., 21, No. 11, 1527-1535, doi:10.1016/S0273-1177(97)00945-9, 1998.
  • Balsiger, H., et al., Rosina Rosetta Orbiter Spectrometer for Ion and Neutral Analysis, Space Sci. Rev., 128, 745-801, doi:10.1007/s11214-006-8335-3, 2007.
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