The quality of the new images is virtually the same as star images taken before the haze appeared. In the most recent treatment, the camera had been warmed to 4 degrees Celsius (39 degrees Fahrenheit) for four weeks ending July 9.

Four previous treatments at that temperature for varying lengths of time had already removed most of the haze. The camera usually operates at minus 90 C (minus 130F) , one of the temperatures at which test images were taken on July 9 of the star Spica.

"We're happy with what we're seeing now," said Robert Mitchell, Cassini program manager at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The team will decide in coming weeks whether to proceed with another warming treatment later this year.

Cassini's narrow-angle camera worked flawlessly for several months before and after a December 2000 flyby of Jupiter. Haze appeared when the camera cooled back to its usual operating temperature after a routine-maintenance heating to 30 C (86F) in mid-2001.

Lens hazing from engine exhaust or other sources is always a possibility on interplanetary spacecraft. Planners designed heaters for Cassini's cameras to cope with just such a situation.

Before treatment, the haze diffused about 70 percent of light coming from a star, by one method of quantifying the problem. Now, the comparable diffusion is about 5 percent, Cassini engineers Charles Avis and Vance Haemmerle report.

That's within one percent of what was seen in images from before the hazing occurred, possibly within the range of statistical noise in the analysis.

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