For several years it was uncertain if AMS-02 would ever be launched because it was not manifested to fly on any of the remaining Space Shuttle flights. After the 2003 "Columbia" disaster NASA decided to reduce shuttle flights and retire the remaining shuttles by 2010. A number of flights were removed from the remaining manifest including the flight for AMS-02. In 2006 NASA studied alternative ways of delivering AMS-02 to the space station, but they all proved to be too expensive.