From the article:
A balloon-based spacecraft could survey Mars with rover-level detail in a fraction of the time it takes with ground-based vehicles, scientists say. The U.S. space agency’s celebrated Mars rovers, Spirit and Opportunity, have each roamed several miles during nearly two years on the planet’s surface. Their mission has been an unqualified success, providing breathtaking images and important data.
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MORE ABOUT PLANETARY BALLOONS
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