Science

Unanswered Questions About Shuttle Columbia

The loss of space shuttle Columbia raises questions about the safety of NASA flights and the agency's budget limitations. Experts discuss the future of the space agency and whether space travel is worth the risk of losing astronauts.

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Space Shuttle Columbia Disintegrates Upon Re-Entry

The space shuttle Columbia disintegrated upon re-entry over Texas Saturday morning moments before its seven-member crew was scheduled to land in Florida.

NASA Statement on the Loss of the Space Shuttle Columbia

By PBS News Hour

The following is the text of a NASA statement on the loss of the Space Shuttle Columbia.

Clonaid’s Deadline Passes With No Proof of Human Clone

French company Clonaid's self-imposed 10-day deadline for providing DNA proof of the existence of the first human clone passed Tuesday without any new evidence from scientists.

You’ve Got E-mail

E-mail, used by almost 90 million Americans, has been changing human communication for almost a decade. Terence Smith reports on e-mail and its effects on American culture.

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Water Fight in the Great Lakes

Fred de Sam Lazaro reports on a fight over water in the Great Lakes.

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The Cloning Debate

A company called Clonaid claims to have produced the world's first cloned human being. Betty Ann Bowser reports.

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How We See

Tom Bearden investigates the mystery of how we see.

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Forests and Fires

Terence Smith discusses the administration's approval of a fire fighting method involving logging and thinning of overgrown forests with the vice president of the Wilderness Society and the executive director of the Political Economy Research Center.

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Stanford University to Create New Stem Cell Lines

Stanford University announced on Tuesday that its researchers will work to create new stem cell lines by employing nuclear transfer technology --a process that can be interpreted as cloning.