An American spy satellite deployed during the Cold War has exploded above our planet without warning — and, so far, scientists can't explain why. The debris cloud from this sudden fragmentation, which experts are still trying to measure, could pose a very "real threat" to other spacecraft in a highly crowded region of low Earth orbit (LEO), experts warn. The spacecraft, known as USA 32 or Farrah III, was launched by the National Reconnaissance Office (NRO) in 1988. Its mission, which was only fully declassified earlier this year, was to intercept Soviet radar and radio signals from space, according to Futura. The cylindrical spacecraft, whose shape has been described as a giant "tuna can," l...