This is a new launch plaform idea to assist Nasa in meeting it's extra-planetary goals. It seems that a large helium-supported platform in the upper atmosphere could save a lot of launch energy and pollution. The platform might be quite large, perhaps 0.5 to 2 km in diameter, and could be used for launching much smaller rockets than a Saturn 5, which would require far less fuel for a similar payload when launched from this height. The platform could be covered in photovoltaic cells for energy, or the underside could receive microwave radiation from a power station on the ground. Launch vehicles, fuel and supplies could be raised to this height using large helium dirgibles for minimal energy cost and pollution. The dirgible gas could be compressed to return to ground, and platform waste used for additional ballast. Possibly an appropriate hydrogen/helium mixture would provide better boyancy without fire risk. Solar power might be used to produce hydrogen and oxygen electrolytically on the platform from ambient water vapour, if enough is available. The platform would include a small base for the launch and operations crew. The platform would rarely if ever return to the ground, instead forming a semi-permanent 'island in the sky'. A larger plaform could be assembled from smaller standardized (hexagonal?) units. Units could be produced and added when required, to smooth production costs and provide flexibility and reduced risks. Multiple units would provide redundancy and safety. More than one platform could be assembled from such units. Different countries could supply units according to their GDP's for an international effort. A multi-layer plaform could provide protected pressurized living and engineering workspaces. The platform might also allow easier reentry, with the start and end of an astronaut's journey being a leisurely balloon trip between the plaform and the ground. This option seems to have many benefits and yet it may be quite possible using existing technology taken to an extreme. The cost savings and might be dramatic over several years of operation, and the additional flexibility and reduction in pollution could provide other benefits. Upper atmosphere winds may prove a problem. The platform(s) would probably be best sited over the oceans to avoid shadowing and visual pollution of populated areas. Later, space tourism could start with visits to the plaform to assist in funding operations.