I had seen the SpaceCast site before, this seems to be related to it but newer: http://www.fas.org/spp/military/docops/usaf/2025/v2c5/v2c5-6.htm Its a good backgrounder on propulsion technology. Lee
AF2025 v2c5-6 Spacelift 2025 The Supporting Pillar... (Appendix A).url