The Rosetta orbiter
Credit: ESA/ATG medialab
Rosetta resembles a large black box. The scientific
instruments are mounted on the top of the box (the
payload support module), while the subsystems are on
the ‘base’ (bus support module). On one side of the
orbiter is the steerable 2.2 m-diameter communications
dish, while the lander is attached to the opposite
face. Two enormous solar wings extend from the other
sides. Both panels can be rotated through ±180°.
The orbiter’s scientific payload includes 11
experiments, in addition to the lander. Scientific
consortia from institutes across Europe and the United
States provided these state-of-the-art instruments.
Ultraviolet Imaging Spectrometer - ALICE will
analyse gases in the coma and tail and measure
the comet’s production rates of water and carbon
monoxide and dioxide. It will provide information
on the surface composition of the nucleus.
Comet Nucleus Sounding Experiment - CONSERT
will probe the comet’s interior by studying radio
waves reflected and scattered by the nucleus.
Cometary Secondary Ion Mass Analyser - COSIMA
will analyse the characteristics of dust grains
emitted by the comet, such as their composition
and whether they are organic or inorganic.
Grain Impact Analyser and Dust Accumulator –
GIADA will measure the number, mass, momentum
and velocity distribution of dust grains coming
from the cometary nucleus and other directions
(deflected by solar radiation pressure).
Micro-Imaging Dust Analysis System - MIDAS will study
the dust around the comet. It will provide information
on particle population, size, volume and shape.
Microwave Instrument for the Rosetta Orbiter
- MIRO will determine the abundances of
major gases, the surface outgassing rate and
the nucleus subsurface temperature.
Optical, Spectrocopic and Infrared Remote
Imaging System - OSIRIS has a wide-angle camera
and narrow-angle camera that can obtain highresolution images of the comet’s nucleus.
Rosetta Orbiter Spectrometer for Ion and
Neutral Analysis - ROSINA will determine the
composition of the comet’s atmosphere and
ionosphere, the velocities of electrified g as
particles and reactions in which they take part.
Rosetta Plasma Consortium - RPC will measure the
physical properties of the nucleus, examine the structure
of the inner coma, monitor cometary activity, and
study the comet’s interaction with the solar wind.
Radio Science Investigation - RSI will, by using
shifts in the spacecraft’s radio signals, measure the
mass, density and gravity of the nucleus, define
the comet’s orbit, and study the inner coma.
Visible and Infrared Mapping Spectrometer - VIRTIS
will map and study the nature of the solids and the
temperature on the surface. It will also identify comet
gases, characterise the physical conditions of the
coma and help to identify the best landing sites.
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