60636
Waivers of the provisions of this act have been required to allow NASA to purchase launch services from Russia , in order to support its manned space program in the period of some years between the retirement of the Space Shuttle and the availability of its successor .
 NASA
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 NASA