Guest: Dallas Bienhoff. Topics On orbit fuel/propellant depots. Dallas Bienhoff was the guest for this Space Show program to discuss orbital fuel/propellant depots. In our first segment, Dallas started out by describing the concept behind the orbital propellant depot which he said was similar in concept to a gas station for cars except it was in orbit. Dallas suggested that by using depots we could increase payload capabilities between 2-3 times were we refueling in LEO today. He also summarized the history of depots which goes back to the early days of the space age. He further said that depots would be an important part of a space transportation system. Another way of expressing the capability was by saying we could go from 20 tons to the Moon without using depots to about 51 tons landed on the Moon if filled up using LEO depots. A listener asked about cryogenic fuel transfer and Mr. Bienhoff explained this challenge to listeners. I asked him what would happen if the depot had a leak in space. Don't miss his answer to this question. Near the end of this segment, we talked about various orbits that could be serviced by a depot. He suggested putting the depots in orbits that most launch vehicles can reach to expand market potential. We also talked about technology challenges and possible show stoppers so don't miss his response to this set of questions. As we started the second the segment, we talked about docking and how the refueling process would be handled. A listener asked if the depots would be made available to private space companies, assuming the depots were government projects. We talked about the potential for offsite refueling using small tugs. We talked about launch and destination timelines using a LEO depot. Another listener asked if we could be a space-fairing nation without the use of depots. Dallas said they are not essential but they do increase what we can put into space. He said that depots are enhancers, not enablers. Listeners asked Dallas about the priority of depots within the Administration's FY2011 budget. Mr. Bienhoff suggested that the depot was a priority program, a flagship program. I then asked him to describe the next steps in the development project assuming the FY 2011 budget is passed as is by Congress later this year. Near the end of this segment, Dallas addressed the boil off issue and the life expectancy of a depot. As we kicked off the third segment, Dallas said that a depot could be located at the ISS as well as on the surface of the Moon or Mars but suggested the fuel be produced on the Moon and Mars rather than brought up from Earth. He also talked about the choice locations for a depot so listen to his suggestions on this. We talked about launch economics with the EELVs and the potential afforded the industry with the Falcon 9. We then applied some of these launch economics to developing SSP and it was said that the use of depots definitely facilitated SSP development. In talking about depot development, Dallas equated policy with needing a customer and that was a critical path to depot development. Much of this segment was focused on the critical path of needing a customer and the potential market. In the end, the depot must make economic sense and be lower in cost than the alternatives. If you have comments or questions for Dallas Bienhoff on orbital fuel depots, please send them to me at drspace@thespaceshow.com and I will forward them to our guest. Please be patient in waiting for a response to your email.