978-1-4222-3418-1

Other astronauts watched from inside the station, while on the ground far below, NASA experts looked on helplessly. It was up to the floating doctor to save the day. Wearing bulky gloves but using delicate tools, the two men carefully installed a new pump that would stop the leak. Marshburn was used to working in pressure situations. This was like life back in the ER . . . in zero gravity. Though his wrench was tied to his glove, Marshburn still held on tightly.Then he carefully tightened the last bolt. Marshburn and Cassidy watched carefully for many minutes to see if any more ammonia leaked out. The situation was tense, but Marshburn remained cool and calm. Finally, after testing the pump, the word came through: All clear! No more leak! When Thomas Marshburn was working as a doctor, he probably never thought that one day he would become a scientist in space! But he was one of dozens of men and women who had taken their love of science to new heights . . . really, really high new heights!

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