Over The Horizon

Hubble Not in Trouble

The Hubble Space Telescope is not a large, orbiting paperweight, according to Professor Bob Hunt of Arizona University's Department of Electrical Engineering.

"For the most part the Hubble has gathered a lot of data that could not have been gathered any other way," said Hunt on a recent visit to New Zealand.

Hunt has seen a great deal of that data, having been part of an international committee set up by NASA to use electronic processing techniques to help improve the quality of the images coming through the optically flawed telescope. Over the past three years, thousands of images have been "massaged" by computer to produce results comparable to what the facility was supposed to have achieved when functioning fully.

Apparently-fuzzy blobs have been resolved to produce images of far-off galaxies, complete with structures and details not visible to ground-based observatories. Simulations were used to check for any possible distortions, indicating that the processed data was near perfect compared to the 10-15% quality of the initial data.

Perhaps not surprisingly, Hunt says that the best results have been obtained with nearby bright objects. The HST has observed long-term global changes on Mars and Jupiter, and has tracked the development of storms on Saturn. Such information may lead to a better understanding of how our own weather systems work. It has also provided the first clear view of Pluto and its companion moon Charon as separate objects, rather than as the fuzzy asymmetric lump shown by Earth-based telescopes.

The Space Science Telescope Institute has been cautious in releasing the results of its tests following the servicing mission last December. Full tests are being run on standard images to check out the success of the repair, but astronomers are confident that the telescope's sensitivity to very faint objects will improve by about 10 times. The initial images released indicate that this confidence is justified.

The repair won't be 100%, as putting extra equipment in the optical path will mean some light loss, but it will be a great improvement over the system to date, Hunt said.

Hunt's image processing skills, developed as part of his work in electronic imaging over the years, have been in demand in other cases. Fifteen years ago he analysed pictures of John F. Kennedy's assassination for the US Congress. He pin-pointed the head's position and traced the bullets' trajectory back to the window of the Texas School Book Depository Building where the gun carrying Lee Harvey Oswald's fingerprints were found.