One of the four science instruments aboard the Hubble Space Telescope suspended operations this week, and engineers are looking into options for recovery, NASA reported Friday.
The instrument — called the Space Telescope Imaging Spectrograph, or STIS —was installed during the second Hubble servicing mission in 1997 and was designed to operate for five years. NASA said it has met or exceeded all its scientific requirements.
Hubble's other instruments — the Near Infrared Camera and Multi-Object Spectrometer, the Advanced Camera for Surveys, and the Wide Field/Planetary Camera 2 — are all operating normally, NASA said.
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 said it has convened an Anomaly Review Board to investigate the cause of the STIS problem and an investigation is under way to determine if the instrument is recoverable.
Preliminary findings indicate a problem with an electrical converter on Side 2 that supplies power to the mechanism's electronics. STIS suffered a similar electrical malfunction in 2001 that rendered Side 1 of the instrument inoperable.
NASA said a final decision on how to proceed would be made in the coming weeks.
STIS currently accounts for about 30 percent of all Hubble scientific observation programs, NASA said. A "standby" list of observing programs for the other science instruments on Hubble can be used to fill the 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 Bruce E. Woodgate of the Laboratory for Astronomy and Solar Physics at NASA's Goddard Space Flight Center.
NASA listed several of the major scientific achievements made by scientists using STIS:
- Independent confirmation of the age of the universe by finding the coolest — and hence the oldest — white dwarf stars that exist in our galaxy.
- A census of galaxies to catalog supermassive black holes. The effort showed that a surprisingly large fraction of galaxies contain a central massive black hole.
- The first-ever measurements of the chemical composition of the atmosphere of an extrasolar planet.
- Detection of the magnetic "footprints" of the Jovian satellites in Jupiter aurora. The instrument also made clear images of Saturn's aurora.
- Observations of the dynamics of circumstellar disks, the region around young stars where planets may form.
- The first evidence of the high-speed collision of gas in the recent supernova remnant SN1987A.
Since January, Hubble's fate has been a point of contention for NASA. The space agency had decided to discontinue servicing of the telescope, due to safety concerns raised by the investigation into last year's Columbia tragedy.
However, the outcry from researchers and lawmakers led NASA officials to reconsider options for future repairs, including robotic missions or even perhaps a space shuttle mission.