Janice Voss, a space shuttle astronaut and scientist who explored the behavior of fire in weightlessness, how plants adapt to extraterrestrial flight and an array of other phenomena while logging nearly 19 million miles circling Earth, died on Monday at a hospital in Scottsdale, Ariz. She was 55 and lived in Houston. (Today)

SAN DIEGO -- Almost hidden in the northern hills, the pilot water treatment plant here does not seem a harbinger of revolution. It cost $13 million, uses long-established technologies and produces a million gallons a day. (Today)

Think of some of the nutrients in your daily vitamins: calcium, potassium, iron, zinc. These are four of the 118 chemical elements from which all matter in the universe is made. But what makes the elements themselves? The answer is shining above you in the sky. Indeed, the building blocks of all substances are chemically created in the stars. (Yesterday)

A piece of Mars fell on Morocco in July. But that was just the start of its travels on Earth. (Yesterday)

SAN FRANCISCO -- Venture deep inside the new skyway of the San Francisco-Oakland Bay Bridge, and it becomes clear that the bridge's engineers have planned for the long term. (Yesterday)