NOZOMI PLANET B

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Nozomi (Japanese for Hope and known before launch
as Planet-B) First Japanese Mars
Orbiter Launched July 4, 1998 Primary Science
Objective to study Martian upper atmosphere with
emphasis on its interaction with solar
wind Weight 541 kg, including the fuel for
attitude and orbit control Status In its
heliocentric orbit to arrive at Mars early in
2004
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Objectives The primary scientific objective is
to study the Martian upper atmosphere with
emphasis on its interaction with the solar
wind. NOZOMI observations are grouped into five
categories Magnetic field of MarsAtmosphere of
Mars Plasma in the Ionosphere of
MarsPicturesDust
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Scientific Instruments To attain these
scientific objectives, fourteen instruments are
installed on NOZOMI spacecraft. MICThe Mars
Imaging Camera - visual wavelength camera MGFThe
Magnetic Field Measurement is designed to measure
the magnetic field around Mars PETThe Probe for
Electron Temperature measures the electron
temperature of the Martian ionosphere ESAThe
Electron Spectrum Analyzer onboard NOZOMI will
measure the electron energy flux in the range of
12 eV to 16 keV ISAThe Ion Spectrum Analyzer
onboard NOZOMI will measure the ion energy flux
in the range of 10 eV to 16 keV per charge
EISThe Electron and Ion Spectrometer onboard
NOZOMI will measure the energy flux of high
energy particles such as electrons, protons,
helium ions and heavy oxygen ions, in the range
of 40 keV to 500 keV per charge XUVThe Extra
Ultraviolet Scanner (XUV) measures the abundance
and distribution of helium gas and helium ions in
the Martian ionosphere by scanning the scattered
extreme ultraviolet sunlight by neutral helium
gas and helium ions More gt
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UVSThe UltraViolet imaging Spectrometer (UVS)
measures the FUV and MUV region from 115 to 310
mm PWSThe Plasma Wave and Sounder (PWS)
instrument with its range of 20 kHz to 5 MHz is
designed to observe the structure of the
ionosphere by using the topside sounder technique
together with the features of plasma waves
associated with wave-particle interactions, which
are the origin of the microprocesses controlling
the direct interaction processes of ionospheric
plasma with the solar wind plasma LFAThe Low
Frequency plasma wave Analyzer (LFA) onboard the
NOZOMI spacecraft has been developed to measure
Martian plasma waves IMIThe Ion Mass Imager
(IMI) is a lightweight ion mass composition
instrument. The IMI measures ions with energies
between 10 eV and 35 keV per charge, and has a
360 degrees field-of-view aperture and uses the
spacecraft spin to cover almost the full unit
sphere to measure three-dimensional distribution
of ions MDCThe Mars Dust Counter (MDC) is a
lightweight impact-ionization type dust detector,
which determines mass and velocity of a particle
NMSThe Neutral Mass Spectrometer (NMS) is a
light weight quadrupole-type mass analyser
TPAThe Thermal Plasma Analyzer (TPA) measures
the characteristics of thermal ions in the upper
atmosphere of Mars, such as velocity, temperature
and their composition
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Spacecraft Technology The spacecraft weighs only
541 kg including fuel. Although it is extremely
lightweight, NOZOMI is still a very
high-performance spacecraft. The spacecraft is a
spinner with a spin rate of 7.5 rpm. The spin
axis points toward the earth because the
communication antenna dish is fixed to the
spacecraft body. The total weight of the 14
onboard scientific instruments is 35 kg while the
dry mass of the spacecraft is 256 kg.
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Trajectory The NOZOMI was launched with M-V
rocket at Kagoshima Space Center (KSC) on July 4,
1998. During orbiting the earth for 4 months,
NOZOMI made its first lunar swing-by on September
24. Then it made the second lunar swing-by on
December 18, and executed a powered earth
swing-by two days later. The earth swing-by was
to send NOZOMI onto a transfer orbit to Mars. Due
to malfunction of a thruster valve during the
powered earth swing-by, however, the NOZOMI
flight control team had to send an uplink command
again to get it back on the right trajectory to
Mars. As a result of this second maneuver, the
NOZOMI team found that NOZOMI no longer had
enough fuel to inject itself into its scheduled
orbit on arrival at Mars. The mission analysis
team managed to find an alternative trajectory to
meet both fuel and observation conditions. Thus
the orbit insertion that was scheduled in October
11, 1999, was abandoned, and a new trajectory
strategy was established. For the moment,
NOZOMI's arrival at Mars is scheduled early in
2004 through two more earth swing-bys in Dec.
2002 and June 2003.
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• Spacecraft Operation
• The telemetry data rate varies from 64 bps to 32
  kbps depending on the distance between Mars and
  the earth. In order to overcome the limitation of
  relatively low typical bit rate of 4 kpbs, an
  onboard solid-state data recorder is used to
  store data at higher recording rates up to 64
  kbps during the periapsis passage. The scheduled
  life of NOZOMI is one Mars year (two earth years)
  at the minimum, which is determined by the amount
  of fuel left after the Mars insertion operation
  in 2004.

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• International Cooperation
• Foreign partners provide some of the instruments
  onboard NOZOMI.
• NASA provides the neutral gas mass spectrometer
  and ultra-stable oscillator for radio science.
• The ion mass spectrometer, thermal plasma
  analyzer, and dust counter, are provided by
  Sweden, Canada, and Germany, respectively.
• The visible camera has been developed in
  collaboration with France.
• The NOZOMI program expects that the international
  collaboration will increase during the data
  analysis phase

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• Status
• Despite its initial fuel problem, Nozomi has
  recovered well and is midway through its long
  journey. Nozomi is providing measurements of the
  interplanetary medium as it travels towards Mars.
  The spacecraft and its instruments are in
  excellent health, and they are expected to enter
  orbit around Mars during January 2004.
• Image During its approaches to the earth and the
  moon for swing-by operations, the NOZOMI team
  operated the Mars Imaging Camera (MIC) to take
  photographs of the earth and the moon.

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• Where is Nozomi Now?
• On the "Where's Spirit Right Now?' web page, one
  of the graphics has been modified to include the
  current positions of the Mars Express and the
  Nozomi spacecraft
• http//mars.jpl.nasa.gov/mer/mission/spiritrightno
  w.html
• It is the 4th graphic down.