One of the primary missions of NASA's most recent spaceflight, the space shuttle Discovery's July trip to the International Space Station, was to test new safety technologies. While the ­shuttle orbited 300 to 400 kilometers above Earth, astronauts tried out new cameras designed to detect damage that the ­shuttle's ­protective tiles might sustain during the trauma of leaving Earth's ­atmosphere. Two astronauts inched out to the end of the ­shuttle's 100-foot robotic arm and boom to test their stability as a tile ­repair platform. Astronauts inside the shuttle and in the space station photographed the project through their windows.

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