During a special symposium hosted by Administrator Sean O'Keefe, NASA examines the similarities between space exploration and other terrestrial expeditions with the help of some of the best known explorers in the world, including mountain climbers, deep sea explorers, scientists and science fiction writers. The discussions also will include NASA astronauts, other notable aeronautics and deep space explorers.

The symposium, "Risk and Exploration: Earth, Sea and the Stars," will be carried live Sept. 27-28 on NASA TV and webcast on www.nasa.gov from the Naval Postgraduate School in Monterey, Calif.

Sessions and participants:

Monday, Sept. 27 - 5:30 p.m. EDT

Session One - Earth
Moderator: Chris McKay, Planetary Scientist, NASA's Ames Research Center (ARC), Calif.

• Ed Viesturs, American High-altitude Mountaineer
• Penny Boston, Director of Cave and Karst Studies, New Mexico Institute of Mining and Technology
• Dale Andersen, Astrobiologist, Antarctic/Arctic researcher, SETI Institute
• Nathalie Cabrol, Planetary Geologist, ARC, SETI Institute
• Bill Stone, President, Stone Aerospace
• David Roberts, Writer specializing in mountain climbing, adventure, and archaeology

Tuesday, Sept. 28 - 12 p.m. and 5 p.m. EDT

Session Two - Sea
Moderator: David Halpern, Senior Policy Analyst, White House Office of Science and Technology Policy

• John Chatterton, Professional Diver, featured in the book, Shadow Divers
• Sylvia Earle, Founder and Chairman, Deep Ocean Exploration and Research
• Jean Michel Cousteau, President, Ocean Futures Society
• Mike Gernhardt, NASA astronaut
• James Cameron, Academy Award winning director, undersea explorer
• Laurence Bergreen, author, Over the Edge of the World: Magellan's Terrifying Circumnavigation of the Globe

Session Three - The Stars
Moderator: John Grunsfeld, NASA Chief Scientist and astronaut

• Harrison Schmitt, former NASA astronaut
• Shannon Lucid, NASA astronaut
• Steve Squyres, Professor of Astronomy at Cornell University, Scientific Principal Investigator for the Mars Exploration Rover mission
• Jim Garvin, NASA Chief Scientist for Mars and the moon
• John Mather, James Webb Space Telescope Senior Project Scientist, NASA's Goddard Space Flight Center
• Graham Yost, Writer/Director, From the Earth to the Moon

Times and participants are subject to change. See the NASA TV schedule on the Internet for the latest updates.

NASA TV is available in the continental United States on AMC-6, at 72 degrees west longitude, Transponder 9, 3880 MHz, vertical polarization, audio at 6.8 MHz. If you live in Alaska or Hawaii, NASA TV is on AMC-7, at 137 degrees west longitude, Transponder 18, at 4060 MHz, vertical polarization, and audio at 6.8 MHz.

For more information about NASA TV or to watch the events on the Internet, visit: http://www.nasa.gov/multimedia/nasatv/index.html