Guests: Kathy Lueders; Dr. Heidi Fearn; Topics: First segment: NASA Commercial Crew. Second segment, Dr. Heidi Fearn re Mach Thrusters. Please direct all comments and questions regarding Space Show programs/guest(s) to the Space Show blog, http://thespaceshow.wordpress.com. Comments and questions should be relevant to the specific Space Show program. Written Transcripts of Space Show programs are a violation of our copyright and are not permitted without prior written consent, even if for your own use.