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NASA official: Rovers weathered dust storm

— Photo: P.V. Sivakumar

THROWING LIGHT ON MARS: James E. Graf of the Jet Propulsion Laboratory, U.S., explains the phenomenon of dust storms on Mars at the International Astronautical Congress near Hyderabad on Tuesday.

HYDERABAD: “It is a real testimony of the engineering skill of NASA [National Aeronautics and Space Administration] personnel that rovers Opportunity and Spirit, exploring the Martian soil, weathered a dust storm that buffeted them for about six weeks from June 2007 and the instruments on board are back in action,” James E. Graf, Deputy Director, Earth Science and Technology, Jet Propulsion Laboratory (JPL), NASA, said on Tuesday.

The two rovers were designed for a life of 90 days but they were going strong even after three years.

In a presentation on dust storms on Mars, Mr. Graf, who was earlier Project Manager for Mars Reconnaissance Orbiter, said the rovers “experienced and lived through a major dust storm on Martian surface.”

The storm blocked sunlight, resulting in reduced amount of sunlight for the rovers’ solar arrays. They used electricity not only to operate the scientific instruments but also to keep alive their computers and producing heat to keep the electronic equipment warm. From the sensors on board, the JPL controllers were able to estimate the sunlight filtering in and based on the estimate they were able to assess the amount of dust in the atmosphere.

At one stage there was less than 5 per cent of the sunlight that would normally fall on the solar arrays. So the JPL controllers did a number of innovations to reduce the energy needed. This included stopping experiments.

Mr. Graf said: “The controllers did a good job in keeping the critical electronic equipment warm. This helped in the rovers weathering the storm. They are back to nominal operations. But some of the equipment are breaking down. The atmosphere is clearing.”

Mr. Graf showed some spectacular slides of the normal features of the Martian soil before the dust storm blew over it and the sand dunes created by the storm, rocky ridges and the Duck Bay in the Victoria Crater where Opportunity moved in June 2007.

The Victoria Crater is 800 km wide and 90 km deep. The slides also showed gullies, which suggested some sort of liquid flow.

Asked whether it was established that there was water on Mars, he replied that scientists felt that they had evidence to believe that there was water on Mars’ surface at one point of time.

“It is millions to billions years ago…The gullies suggest some sort of liquid flow. What that liquid is, we do not know,” he said.

Phoenix, launched in August 2007, was on its way to Mars and it would land in May 2008. It will scoop out soil and analyse whether it had ice. NASA will launch Mars Science Laboratory, a rover of the size of a small automobile, in 2009. It will land in 2010.

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