One of four science instruments aboard NASA’s Hubble’s
Space Telescope suspended operations earlier this week, and
engineers are now looking into possible recovery options.
The instrument, called the Space Telescope Imaging
Spectrograph (STIS), was installed during the second Hubble
servicing mission in 1997 and was designed to operate for
five years. It has either met or exceeded all its scientific
requirements.
Hubble’s other instruments, the Near Infrared Camera and
Multi-Object Spectrometer (NICMOS), the Advanced Camera for
Surveys, and the Wide Field/Planetary Camera 2 are all
operating normally.
The STIS instrument, which went into a suspended mode
Tuesday, was not slated for replacement or upgrade as part of
any future servicing mission.
NASA has convened an Anomaly Review Board to investigate the
cause of the STIS problem and an investigation is underway to
determine if the instrument is recoverable.
Preliminary findings indicate a problem with the +5V DC-DC
power converter on Side 2, which supplies power to the
mechanism’s electronics. STIS suffered a similar electrical
malfunction in 2001 that rendered Side 1 inoperable.
A final decision on how to proceed is expected in the coming
weeks as analysis of the problem progresses.
In the current observing cycle, STIS accounts for about 30
percent of all Hubble scientific observation programs. A
“standby” list of peer reviewed and approved observing
programs for the other science instruments on Hubble can be
used to fill the observing time now available.
The high sensitivity and spatial resolution of STIS enabled
astronomers to search for massive black holes and study star
formation, planets, nebulae, galaxies, and other objects in
fine detail.
STIS was developed jointly with Ball Aerospace under the
direction of principal investigator Dr. Bruce E. Woodgate of
the Laboratory for Astronomy and Solar Physics at NASA’s
Goddard Space Flight Center, Greenbelt, Md.
Among the major scientific achievements made by scientists
using STIS were:
- Independent confirmation of the age of the universe by finding the coolest and hence oldest white dwarf stars that exist in our galaxy
- Conducted an efficient census of galaxies to catalog supermassive black holes. The fraction of galaxies that prove to contain a central massive black hole has proven to be surprisingly large
- Made the first-ever measurements of the chemical composition of the atmosphere of an extrasolar planet
- Saw the magnetic “footprints” of the Jovian satellites in Jupiter aurora, and made clear images of Saturn’s aurora
- Studied the dynamics of circumstellar disks, the region around young stars where planets may form
- Found the first evidence of the high-speed collision of gas in the recent supernova remnant SN1987A
Additional information about STIS is available on the
Internet at:
