Final Endeavour shuttle launch delayed

Physics Today : The final launch of the space shuttle Endeavour, scheduled for today, has been delayed for at least 48 hours because of a problem with the heaters associated with the shuttle’s auxiliary power unit, according to Manuel Roig-Franzia writing for the Washington Post. Officials at first thought the weather would cause a delay, but forecasters predicted the skies would clear in time. Endeavor is scheduled to deliver the Alpha Mass Spectrometer (AMS-2), the “first fundamental science experiment to the International Space Station,” says Nobel Prize winner Samuel Ting, AMS-2’s principle investigator. The $2 billion experiment, a collaboration between more than 40 institutions and 600 physicists, has taken more than 17 years to reach this point and has suffered dramatic setbacks, including the loss of its ride to the space station following the space shuttle Columbia disaster in 2003 and the last-minute replacement last year of its superconducting magnet with a less powerful permanent magnet.