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SpaceX  was founded in June 2002 by PayPal and Tesla Motors co-founder  Elon Musk  who had invested US$ 100 million of his own money by March 2006 .
 founded by: SpaceX, Elon Musk
Given options, please tell me the relationships of all the listed entity pairs.Output format is "relation1: word1, word2; relation2: word3, word4". 
Option: cities of residence, top members employees, members, alternate names, origin, state or provinces of residence, title of person, spouse, city of headquarters, NA, founded by, state or province of headquarters, employee of, countries of residence, country of birth, founded, subsidiaries, country of headquarters 
Text: {0} 
 Entity Pairs:  SpaceX, Elon Musk 
Answer:
 founded by: SpaceX, Elon Musk