Monthly Archives: August 2004

hubble space telescope, starbirth

A Postcard from HST

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Courtesy Hubble Space Telescope Science Institute
Courtesy Hubble Space Telescope Science Institute

Vacations always mean postcards or email from friends, usually ones lucky enough to be off somewhere exotic taking in the sights. HST has been transmitting images and data from the cosmos’s hotspots since 1990, and with very few exceptions, its views of the universe (from Earth orbit) are inspiring.

This one is a peek inside a gas cavity inside a molecular cloud. The cave is carved by the stellar wind and intense ultraviolet radiation from a nearby hot young star. This particular “exotic locale” is located about 160,000 light-years away in the Large Magellanic Cloud, a companion galaxy to the Milky Way.

So, if HST could send us back a postcard, what would it write? Let’s see!

On closer inspection N44F harbors additional surprises. The interior wall of its gaseous cavity is lined with several four- to eight-light-year-high finger-like columns of cool dust and gas. (The structure of these “columns” is similar to the Eagle Nebula’s iconic “pillars of creation” photographed by Hubble a decade ago, and is seen in a few other nebulae as well). The fingers are created by a blistering ultraviolet radiation from the central star. Like windsocks caught in a gale, they point in the direction of the energy flow. These pillars look small in this image only because they are much farther away from us than the Eagle Nebula’s pillars.

Want a bigger version of this image? Point your browser here.

hubble space telescope

Are We Watching the Slow Decline of an Old but Useful Friend?

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Yesterday NASA and the Space Telescope Science Institute announced that the Space Telescope Imaging Spectrograph had been shut down due to failure of electronic parts. Here’s the announcement:

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.

This is exceedingly worrisome. For now the telescope is working (what’s left of it), but as time goes by, more parts will fail, and ultimately we will watch as a productive and spectacular observatory is allowed to fall into disrepair. I understand the safety issues involved in shuttle repair missions for HST, but I wish there were a way to continue the productive life of this great observatory.