Free Republic

One of the most futuristic and far-fetched is the space elevator....simple enough on paper – extend a 22,000 mile set of cables from a space station in geostationary orbit to a corresponding structure somewhere at Earth's equator. ... The problem...is that the cable system must be constructed from a material far stronger than anything known. Carbon nanotubes have been hypothesized to fill this niche, but they aren't ready yet. … Another potential rocket replacement is StarTram…. Magnetically-levitated spacecraft will be propelled inside a curved tube aimed skyward. All air will be evacuated from the tube in order to eliminate drag....

It boils down to building a maglev train to outer space. Here's how it works: Magnetically-levitated spacecraft will be propelled inside a curved tube aimed skyward. All air will be evacuated from the tube in order to eliminate drag. Craft will exit the lengthy tube at a speed of 8.8 kilometers per second in order to escape Earth's atmosphere. ... There are four key hurdles that need to be overcome for StarTram to work. First off, to propel spacecraft to necessary speeds, a massive amount of power will need to be stored and discharged over roughly thirty seconds, think between...