NASA Concludes Successful FUSE Mission
Goddard Space Flight Center, Greenbelt, Md.
WASHINGTON - After an eight-year run that gave astronomers a completely
new perspective on the universe, NASA has concluded the Far Ultraviolet
Spectroscopic Explorer mission. The satellite, known as FUSE, became
inoperable in July when the satellite lost its ability to point
accurately and steadily at areas of interest. NASA will terminate the
mission Oct. 18.
Image right: FUSE studies primordial chemical relics of the Big Bang, from which all the stars, planets and life evolved. FUSE was launched aboard a Boeing Delta II rocket, and lifted off from Cape Canaveral Air Station, Florida on June 24, 1999. Click image for enlargement. Credit: NASA
"FUSE accomplished all of its mission goals and more," said Alan Stern,
associate administrator for the Science Mission Directorate at NASA
Headquarters, Washington. "FUSE vastly increased our understanding of
our galaxy's evolution and many exotic phenomena and left a strong
legacy on which to build the next generation of investigations and
Launched in 1999, FUSE helped scientists answer important questions
about the conditions in the universe immediately following the Big Bang,
how chemicals disperse throughout galaxies, and the composition of
interstellar gas clouds that form stars and solar systems.
"FUSE helped pioneer low-cost, principal investigator-led astronomy
missions," said Jon Morse, director of the Astrophysics Division at NASA
Image above: This is a false-color image of the star AE Aurigae (bright source of light slightly off center of image) embedded in a region of space containing smoke-like filaments of carbon-rich dust grains, a common phenomenon. Such dust might be hiding deuterium, an isotope of hydrogen, and stymieing astronomers' efforts to study star and galaxy formation. The FUSE satellite has surveyed the local deuterium concentration in the galaxy and found far more than expected. Because deuterium is a tracer of star and galaxy evolution, this discovery could radically alter theories about how stars and galaxy form. Credit: T.A. Rector and B.A. Wolpa, NOAO, AURA, and NSF
Examples of the many successes FUSE achieved during its mission:
By measuring abundances of molecular hydrogen (made of two hydrogen
atoms), FUSE showed that a large amount of water has escaped from Mars,
enough to form a global ocean 100 feet deep.
FUSE observed a debris disk that is surprisingly rich in carbon gas
orbiting the young star Beta Pictoris. The carbon overabundance
indicates either the star is forming planets that could end up as
exotic, carbon-rich worlds of graphite and methane, or Beta Pictoris is
revealing an unsuspected phenomenon that also occurred in the early
FUSE discovered far more deuterium, a form of hydrogen with a proton
and a neutron instead of just one proton, in the Milky Way galaxy than
astronomers had expected. Deuterium was produced in the early universe,
but this isotope is destroyed easily in stellar nuclear reactions. "FUSE
showed that less deuterium has been burned in stars over cosmic time, in
agreement with modern models for the evolution of the galaxy and the
recent Wilkinson Microwave Anisotropy Probe results," said Warren Moos,
FUSE principal investigator, Johns Hopkins University, Baltimore.
FUSE saw that an atmosphere of very hot gas surrounds the Milky Way.
The ubiquity of hot gas around our galaxy demonstrates the galaxy is
even more dynamic than expected.
By detecting highly ionized oxygen atoms in intergalactic space, FUSE
showed that about 10 percent of matter in the local universe consists of
million-degree gas floating between the galaxies. This discovery might
help resolve the long-standing mystery of the universe's "missing
baryons." Baryons are subatomic particles, often protons and neutrons.
Calculations of how many baryons were produced in the very early
universe predict about twice as many baryons as astronomers have
observed. The rest of the missing baryons might exist as even hotter
gas, which could be observed by future X-ray observatories such as
"FUSE collected quality science data for eight years, longer than its
five-year goal. By any measure, FUSE was a success," said George
Sonneborn, FUSE project scientist at NASA's Goddard Space Flight Center,
Although FUSE's mission has ended, NASA's ultraviolet study of the
universe continues. In 2008, NASA will conduct a servicing mission to
the Hubble Space Telescope to install a new ultraviolet spectrograph on
the telescope and repair another. The new Cosmic Origins Spectrograph,
or COS, is designed to study remote galaxies and nearby stars in the
ultraviolet. Hubble's Space Telescope Imaging Spectrograph also will be
repaired. That instrument had ultraviolet capabilities complementary to
the COS and was used in conjunction with FUSE when both were
operational. The spectrograph failed due to an electronic short in
August 2004 after more than seven years of in-orbit operations.
FUSE was a joint mission of NASA, the Canadian Space Agency and the
French Space Agency, the Centre National d'Etudes Spatiales. The Johns
Hopkins University built the telescope and managed the mission.
The University of Colorado, Boulder, built FUSE's spectrograph. The
University of California, Berkeley, made the detectors.
+ FUSE Mission Web Site