MOFFETT FIELD, Calif. – Friday’s scheduled launch of NASA’s Phoenix Mars Lander aboard a United Launch Alliance Delta II rocket from Cape Canaveral, Fla., has been postponed 24 hours. The two available launch times on Saturday, Aug. 4, are 2:26 a.m. and 3:02 a.m. PDT.

The prelaunch news conference is now scheduled for Thursday, Aug. 2, at 11 a.m. PDT at the NASA press site at NASA Kennedy Space Center, Fla. Immediately after the news briefing, NASA Ames Research Center will provide local reporters in Ames’ main auditorium an opportunity to view a Phoenix mission science briefing at NASA Kennedy, and then ask questions of NASA scientists about the Phoenix spacecraft’s mission to Mars.

Due to a forecast for severe weather around the Kennedy Space Center launch pad in Florida on Tuesday afternoon, fueling of the spacecraft’s second stage will not be completed. Although fueling is expected to be finished Wednesday morning, there is insufficient contingency time in the schedule to move forward with the launch on Friday.

The Phoenix spacecraft will land in the arctic region of Mars and attempt to answer questions such as: Can the martian arctic support life? What is the history of water at the polar landing site? How is the martian climate affected by polar seasonal change?

In addition to scientists at NASA Kennedy, Phoenix scientists from NASA Ames and the SETI Institute, Mountain View, Calif., will be available at Ames to answer local reporters’ queries after the televised briefing.

Phoenix scientists available at NASA Ames will be:

  • Chris McKay, Phoenix co-investigator, biological interpretation, from NASA Ames
  • Aaron Zent, Phoenix co-investigator, soil-atmosphere interaction, from NASA Ames
  • Richard Quinn, Phoenix researcher, NASA Ames and SETI Institute, Mountain View, Calif.
  • John Marshall, Phoenix co-investigator, soil science, geological studies, SETI Institute, Mountain View, Calif.

The news briefing participants in Florida will be:

  • Michael Meyer, lead scientist for Mars, NASA Headquarters, Washington
  • Peter Smith, Phoenix principal investigator, University of Arizona, Tucson, Ariz.
  • Ray Arvidson, co-chairman, Phoenix Landing Site Working Group, Washington University, St. Louis
  • Leslie Tamppari, Phoenix project scientist, NASA Jet Propulsion Laboratory, Pasadena, Calif.
  • William Boynton, lead scientist for thermal and evolved-gas analyzer, University of Arizona
  • Michael Hecht, lead scientist for microscopy, electrochemistry and conductivity analyzer, NASA Jet Propulsion Laboratory, Pasadena, Calif.

The news conference will be carried live on NASA Television and the agency’s Internet homepage, www.nasa.gov. For NASA TV downlink, schedule and web video streaming information, visit: http://www.nasa.gov/ntv

For more information about Phoenix, please visit:

http://www.nasa.gov/centers/ames/missions/2007/phoenix.html

All other planned events for the news media will occur 24 hours after their originally scheduled times. NASA Television and Web coverage will begin at 12:30 a.m. PDT on Saturday. For more information about the Phoenix mission, visit:

http://www.nasa.gov/phoenix

To reach Ames, take U.S. Highway 101 to the Moffett Field, NASA Parkway exit and drive east in the right lane towards the main gate. A security guard will direct visitors to park in a small lot to the right, near the Visitor Badge Office where U.S. citizens will be asked to present government picture identification, such as a valid driver’s license. News media representatives will be provided directions to Ames’ main auditorium.