217138
Liftoff occurred at 21:00 UTC on 21 April 2013 , from Pad 0A of the Mid-Atlantic Regional Spaceport , following attempts on 17 and 20 April which had been scrubbed due to an umbilical problem and high-level winds respectively .
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Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
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