NASA on Thursday delayed the final two flights for the Space Shuttle before it is retired. The last flight, on the shuttle Endeavour, now moves to 26 February. That will give Nobel Prize winner Sam Ting more time to ready his Alpha Magnetic Spectrometer, a $2 billion Department of Energy experiment that is supposed to ride on Endeavour and be attached to the space station. The giant space magnet, which has had a colorful history, should detect cosmic rays, and maybe even dark matter, indirectly. This spring, Ting made a last second switch, swapping the pricey superconducting magnet at the core of AMS for a cheaper permanent one that already flew on the shuttle in 1998. At a DOE meeting in June, Ting insisted that the switch would benefit the mission’s science goals. Because NASA was extending the life of the space station, Ting said, the permanent magnet would collect data for at least a decade, rather than be limited by the three-year lifetime of the liquid helium cooled superconducting magnet.