Deep space probe recovers its clear sight

Drawing of Cassini studying Saturn

(CNN) -- A Saturn-bound spacecraft that developed blurry vision in its camera has experienced an encouraging recovery, according to mission managers.

NASA's Cassini probe took test images of a star earlier this month and the results indicate that haze in the camera lens had cleared up, Cassini project manager Robert Mitchell said.

The cure for the fog? Lots of heat. The lens was warmed for two months to a temperature just above freezing, with heaters built into the camera. The normal operating temperature of the camera is minus-130 degrees Fahrenheit (minus-90 degrees Celsius).

"The new images of the bright star Spica show that, by one measure, at least 90 percent of the image diffusion originally caused by the lens haze has been corrected," said NASA's Jet Propulsion Laboratory in Pasadena, California, which manages the mission.

Such lens warming has helped correct blurry vision on other deep space probes in the past. Cassini is now undergoing another month of heat treatment that could improve the condition even more, according to jet lab ground controllers.

The onboard camera worked well when Cassini visited Jupiter in December 2000. But it developed the vision fog last year during the flight between Jupiter and Saturn.

Launched in 1997, Cassini should reach its primary destination in late 2004. Six months into its orbit of the Saturn system, the craft will drop a European Space Agency probe into the thick atmosphere above Titan, a planet-sized moon that contains many complex organic compounds.