Excerpt

The  development  and  expansion  of  commercial  human  spaceflight  requires legal  and  regulatory  mechanisms  to  provide  a  robust  framework  under
which  commercial  operators  can  fly  paying  participants.  The  term
‘participant’  is  specifically  chosen  as  opposed  to  ‘customer,’  as  it  is  the
term used in FAA regulation in order to distinguish them  from ‘passengers.’

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