1. Impedance Matching Between LEO And BEO Rand Simberg Wyoming Aerospace Space Access Conference April 9, 2010 Phoenix, AZ

2. LEO As A Harbor Recent Quote From Pete Worden: “You can look at low Earth orbit as Earth's harbor, and you don't need a government tug boat company anymore.“ Is This A Good Analogy?

3. Harbor Tug Analogy Has Problems Commercial Companies Aren't Going To Guide Or Tow Space-Faring Vessels To/From Earth Surface (Tug Analogy) Anchoring In Deep Harbor With Shallow-Draft Boats For Access Better Analogy Harbor Is Atmosphere, Earth Is Dock BEO Is Ocean

4. Vehicle Requirements Conflict Earth-LEO-Return Has Dramatically Different Requirements Than In-Space Transportation  Earth/LEO – High T/W, Atmospheric Operations, Extreme Aerothermodynamics, High Structural Stress (Small Speedboat)  In-Space – Varying T/W, Vacuum, Little/No Atmospheric Interaction, Orbital Mechanics, Low Structural Stress (Ocean Liner) Aeronautics Versus Astronautics Having To Do Both With Single Vehicle Gets Very Expensive (e.g., Apollo, Shuttle) Have To Interface Them In LEO (Part of “Impedance Matching”)

5. The Ideal Scenario The Clarke Vision  Pan Am Shuttle For ETO And Back  LEO Space Facility For Transit  Lunar (And Beyond) Excursion Vehicles (At Least) Two Problems  Fitting Through The LEO Portal  Getting To The LEO Portal

6. Fitting Through The Portal ISS Was Extruded Through A Five-Meter Hole  Lots Of Programmatic Stiction/Friction  Probably Cost $20M Per Foot (~1500 feet)  We Should Be Able To Do Better What Is The Minimum Maximum Diameter?  What drives it? Optics? Tankage? Do We Need Not “Heavy Lift,” But Really-Wide Fairing? How To Deliver Items To Ocean Liner With Speedboat?

7. Getting To The Portal How Accessible Is LEO From BEO?  Orbital Mechanics Constraints  Delta Vee Issues Do All Paths To LEO Go Through Earth Surface? Can We Innovate Architecture To Allow LEO Return Via Aerobraking? Can We Make In-Space Propellant Cheap Enough For Propulsive Circularization?