MESSENGER — a spacecraft designed to capture photographs
and other data of Mercury — begins its itinerant journey to
the planet today, making it the first spacecraft to travel there
since the National Aeronautics and Space Administration sent
Mariner 10 in 1973.
MESSENGER, designed to provide scientists with more detailed
observations of Mercury, includes an instrument created by
University scientists, called Fast Imaging Plasma Spectrometer.
Engendered to capture photographs and other data from a planet,
flyby spacecrafts like MESSENGER encounter a wide variety of tumult
and hazard in its lifetime. Faced with strong solar winds, high
radiation levels and extreme temperatures, the spacecrafts must be
designed specifically to avoid calamity while sending valuable
information back to Earth. NASA has sent more than 20 flyby
spacecrafts into our solar system.
The Solar Helospheric Research Group, made up of faculty and
students from the department of Atmospheric, Oceanic and Space
Sciences at the University, has developed FIPS in part to be a
solution to the hostile environment a spacecraft encounters while
circling Mercury. Because of its proximity to the sun, the plasma
surrounding Mercury is characterized by extremely hot temperatures
and high density. FIPS has the capability to counter these harsh
conditions while providing scientists with highly accurate
measurements of Mercury’s atmosphere.
Pat Koehn, assistant resident scientist on the Research Group,
said FIPS acts like a camera, recording the mass, direction and
speed of particles floating around Mercury’s orbit. It will
also determine exactly what type of particles exist in its
In NASA’s first attempt to glean information from Mercury
30 years ago, the plasma spectromete — Mariner 10’s
instrument comparable to FIPS, did not work because the door failed
to open, Koehn said.
“Mariner 10 only did three flybys of the planet, but
MESSENGER will be in orbit for at least one earth year —
roughly four Mercury years. This trip to Mercury will be different
in every way imaginable,” he said.
One of the key goals of MESSENGER is to understand
Mercury’s surface, said Thomas Zurbuchen, a member of the
team and an associate professor in the department of Atmospheric,
Oceanic and Space Sciences. His team and NASA expect the spacecraft
to return to Earth with high resolution maps and more information
on Mercury’s magnetic field.
Of the terrestrial planets Earth, Mercury, Mars and Venus,
Mercury is the smallest. It also has the oldest surface and the
most extreme variability in temperature, ranging from –297 to
800 degrees Farenheit. Because of this severe climate, Mercury has
long been a mystery to scientists.
“Mercury still stands out as a fascinating story to tell.
MESSENGER should complete the detailed exploration of the inner
solar system — our planetary backyard — and help us to
understand forces that shaped planets like our own,” said
Orlando Figueroa, director of Solar System Exploration Division at
NASA, in a press release.
For the past 30 years, scientists at the University have been
involved in nearly every major space project, Koehn said. Most
recently, the University has contributed to CASSINI, a spacecraft
that penetrated Saturn’s orbit in June 2004 and Galileo,
which entered Jupiter’s atmosphere in September 2003.
“We here at U of M are specializing in understanding and
predicting the space environment of planets, most importantly, the
Earth,” said Zurbuchen.
MESSENGER is scheduled to launch from Cape Canaveral Air Force
Station, Fla. during a 13-day period that opens August 2, 2004. A
year later, it will return to Earth for a gravity boost, then fly
past Venus twice, in October 2006 and June 2007. It will finally
reach Mercury in 2011.