ABSTRACT: The Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA) will answer important questions posed by the mission’s
main objectives. After Giotto, this will be the first time the volatile part of a comet will be analyzed in situ. This is
a very important investigation, as comets, in contrast to meteorites, have maintained most of the volatiles of the solar nebula.
To accomplish the very demanding objectives through all the different phases of the comet’s activity, ROSINA has unprecedented
capabilities including very wide mass range (1 to >300 amu), very high mass resolution (m/Δ m > 3000, i.e. the ability to resolve CO from N2 and 13C from 12CH), very wide dynamic range and high sensitivity, as well as the ability to determine cometary gas velocities, and temperature.
ROSINA consists of two mass spectrometers for neutrals and primary ions with complementary capabilities and a pressure sensor.
To ensure that absolute gas densities can be determined, each mass spectrometer carries a reservoir of a calibrated gas mixture
allowing in-flight calibration. Furthermore, identical flight-spares of all three sensors will serve for detailed analysis
of all relevant parameters, in particular the sensitivities for complex organic molecules and their fragmentation patterns
in our electron bombardment ion sources.
Space Science Reviews 01/2007; 128(1):745-801. · 3.61 Impact Factor
Advances in Space Research, v.34, 1647-1649 (2004).
Journal of Geophysical Research, v.108 (2003).
Rosetta-ESA's Mission to the Origin of the Solar System, 485-536 (2009).
Space Science Review, v.115, 299-361 (2004).
ABSTRACT: The Hydrogen Deuterium Absorption Cell (HDAC) is part of the Ultraviolet Imaging Spectrograph (UVIS) experiment aboard the Cassini spacecraft. During Cassini’s Earth swingby on August 18, 1999, HDAC was used as a photometer to measure solar Lyman-α radiation scattered by the neutral hydrogen atoms of the geocorona. These data provide information about the hydrogen column density along HDAC’s line of sight during the Earth swingby. The data cover a large part of the Earth’s exosphere and enable us to determine the distribution of hydrogen atoms in this region. The results are compared to predictions of models providing hydrogen densities of the Earth’s exosphere/geocorona. We found that the models overestimate the decrease of hydrogen density for increasing distance from the Earth.
Advances in Space Research.