Guest: Dr. Marcelo Vazquez. Topics: Space radiation with a focus on humans to Mars. 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. We do not permit the commercial use of Space Show programs or any part thereof, nor do we permit editing, YouTube clips, or clips placed on other private channels & websites. Space Show programs can be quoted, but the quote must be cited or referenced using the proper citation format. Contact The Space Show for further information. In addition, please remember that your Amazon purchases can help support The Space Show/OGLF. See www.onegiantleapfoundation.org/amazon.htm. For those of you interested in the opportunity to submit feedback on the NRC congressionally mandated Human Spaceflight Study, please go to www.nationalacademies.org/humanspaceflight. Please remember that your Amazon Purchases Can Help Support The Space Show/OGLF (http://www.onegiantleapfoundation.org/amazon.htm). We welcomed back Dr. Marcelo Vazquez back to discuss space radiation and mostly human spaceflight to Mars though we covered much ground dealing with space radiation, the risk to humans, mitigation and shielding, as well as policy issues. During the first segment of our 1 hour 38 minute program, we jumped right into it by my asking our guest about the radiation risks, exposure levels, and survival odds for both the Inspiration Mars mission and the Mars One effort to send settler to Mars on a one way mission starting late 2020 or 2021. This was a detailed and comprehensive discussion of the issues for these missions, the state of the art shielding availability, possible technology advancements, and more. We also talked about radiation & pregnancy on a Mars mission, radiation & a young child on Mars or in space, cosmic rays, solar events & extrapolations from radiation oncology. Doug called to ask about the need for a solar storm shelter in case of a solar particle event. Before the end of the first segment, we talked about ISS analogs, antioxidants, and electromagnetic shielding possibilities. In the second segment, Michael sent an article about the LRO analysis suggesting light weight materials and plastics might shield astronauts on the Moon. Dr. Vazquez said this was in keeping with what was known. Joel sent a note asking about RLIP76 and spaceflight, a subject on which our guest had much to say. Our guest went into detail about the radiation impact on a human system, including the destruction of blood vessels. In this light, I asked him about radiation and epithelial cells & if this was a show stopper for HSF, especially to Mars. Another question came in on antioxidants and while they might be helpful to some degree, they might also need to be taken at levels that are at or near toxic to humans. Another listener asked about radiation & telomeres, then we talked about valid analog space radiation studies here on Earth. I asked our guest about other nations doing HSF radiation research, then Jeff called in to discuss the Curiosity radiation findings and the regulatory questions involved since a person going to Mars would exceed the radiation dose allowed by existing OSHA & other regulations. We talked about the validity of Inspiration Mars as a research study & as the program ended, we talked about neurological and cognitive radiation impact & some tests Inspiration Mars crews could do in this area on the mission. Post your comments/questions on The Space Show blog above. You can send a note to our guest by using my email address.