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Broadcast 1203 (Special Edition)Listen to the show!
Aired on August 6th, 2009
Guest: Mark Hempsell
Guest: Mark Hempsell. Topics: Reaction Engines, Ltd., SKYLON, special heat exchangers, low cost space access. We welcomed first time guest Mark Hempsell. Mark is the Futures Program Director for Reaction Engines, Ltd. in the UK. I suggest you follow along on their website with this interview at . In the first segment, Mark started out by referencing previous efforts by Reaction Engines, Ltd. with the HOTOL space shuttle project that was cancelled by the British government. This easily transitioned the discussion to the need for launch vehicles that were reusable like an airplane, this is what Reaction Engines is working on with the SKYLON vehicle. Mark talked about the uniqueness of the vehicle which uses a special type of heat exchanger which almost instantly cools air which is at 1,000 degrees in the engine down to -140 degrees so it can be used by the SKYLON spacecraft. Listen to this discussion and Mark's explanation and description of this technology. Mark also talked about the performance criteria and he explained their testing program in detail. You certainly want to hear about their testing program and how it differs from other testing programs we have heard discussed in the media and on this show. In the second segment, we started out by identifying the capacity of SKYLON. For example, the C1 version can hold about 20 passengers. The D1 version can hold about 24 passengers. As this is an orbital vehicle, it can be used for transporting cargo to the ISS or for orbital space tourism, satellite launches, etc. Mark guessed that the tourism price would be around $1,000,000, but since Reaction Engines will not be the operating company and the hope competition exists in the marketplace, the price could be lower. We discussed orbital tourism versus suborbital and he thought orbital was a better venture for commercial success because of the vehicle R&D costs for suborbital and orbital spaceships. This is a discussion you will certainly want to hear. We also talked about ways to improve the launch rate because even the SKYLON needs a higher launch rate to be more cost effective. One of the things Mark offered was that, since the vehicle would be sold to entrepreneurs and operators, leaving them to decide the market and the usage would be far better for finding space applications and ventures that do demand a higher launch rate than were they the only vehicle operator. He mentioned trusting in the market. In the third segment, I asked Mark if this was a time of golden opportunity for space development and vehicle investment given the upswing in the interest in space. He suggested the SKYLON could have been done in the 1980s, but the timing was not right. There is better timing now and there is government interest, but the future of course is still an unknown for the space markets and even the completion of the technology to a final commercial vehicle. We also talked about the differences with the SKYLON approach to a Rocketplane type vehicle, a carrier vehicle and even a high altitude balloon. In the fourth segment, we talked about the SKYLON capability for launching and retrieving satellites. The market for returning payloads to Earth was discussed and while SKYLON will have a limited capability to do that, initially it will only be able to return payloads that are manually put in the vehicle. We also discussed the total investment to date in SKYLON and Reaction Engines, Ltd. and the cost estimates for designing and building an orbital space vehicle as well as a suborbital vehicle. If you have questions or comments for Mark Hempsell, use the contact page, . Additionally, you can use the email address . Please be sure to put Space Show in the subject line of your note.

About our guest...

Mark Hempsell
Mark Hempsell is the Futures Program Director for Reaction Engines Ltd. Former Spacecraft Systems Engineer for British Aerospace Space Division and Senior Lecturer in Astronautics at University of Bristol. Significant expertise in satellite programmes and space infrastructure. A past President of the British Interplanetary\Society and currently Editor of the Society’s Journal. Mark has his B.Sc in Physics from Imperial College (1978) and his M.Sc (with Distinction) in Astronomy and Astronautics from Hatfield Polytechnic (1982). Visit their website at

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