Guest: Mark Hempsell. Topics: Reaction Engines, LTD & their Skylon space propulsion system. You are invited to comment, ask questions, and discuss the Space Show program/guest(s) on the Space Show blog, http://thespaceshow.wordpress.com. Comments, questions, and any discussion must be relevant and applicable to Space Show programming. Transcripts of Space Show programs are not permitted without prior written consent from The Space Show (even if for personal use) & are a violation of the Space Show copyright. We welcomed back Mark Hempsell for Skylon updates and progress reports since his last visit on August 6, 2009. During our first segment, Mark started with an update saying they are nearing the end of the technology development stage for their space vehicle system. We then went back to the basics and he described the Skylon project for us. Mark talked at length about the Sabre engine, the radiator, their SSTO plans, and more. Several listener emails came in wanting to know about the market and business plan model for Skylon, the space tourism module and profile, and if it could be used for point to point transportation. We learned that for cargo, Skylon flies without a crew. With passengers on board, there will be a crew. Also discussed were orbital characteristics for the vehicle, docking with the ISS and the new ISS docking standards which may present problems for Skylon. You can check out these standards at http://internationaldockingstandard.com. Mark mentioned the various rocket fuels, tonnage to LEO and GEO, crew and passenger configuration, and the two day turnaround period. In the second segment, we resumed talking about the vehicle operating costs. Michael called in to talk about emergency landing options given runway constraints discussed in the first segment. Next up was the thermal protection system (TPS) and we learned that the skin was a type of glass, silicon carbonate that can take1,000 C and that is why Skylon is black. Later, we talked about funding, government subsidies, & private investment. Mark got a question about using scramjet technology and he had much say about this. Another topic was the flight profile and G-loads to be placed upon Skylon occupants. Near the end, we talked about ITAR and potential U.S. investor investment. Skylon test flights will likely be in 2020. Our guest also talked about ESA and other organizational oversight. If you have comments/questions, please post them on The Space Show blog. Visit Skylon' s website, www.reactionengines.co.uk.