Startram - maglev train to low earth orbit [View all]

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"it should be possible using only existing technology ... Sandia National Laboratories has carried out a '"murder-squad" investigation of the Startram concept, whose purpose is to find any flaw in a proposed project. They gave Startram a clean bill of health."

http://www.gizmag.com/startram-maglev-to-leo/21700/

Startram - maglev train to low earth orbit

By Brian Dodson
01:58 March 9, 2012


The Startram orbital launch system would transport passengers and cargo into space in a magnetic levitation (maglev) train
Image Gallery (7 images)

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If the entire Startram tube is at sea level, on exiting the tube the spacecraft will suddenly be subjected to several hundred g's due to atmospheric drag - rather like hitting a brick wall. To reduce this effect to a tolerable acceleration, the end of the Startram vacuum tube must be elevated to an altitude of about 20 km (12 miles). At this height, the initial deceleration from atmospheric drag will be less than 3 g's, and will rapidly decrease as the spacecraft reaches higher altitudes.

This new requirement begs the question - how do we hold up the exit end of the Startram vacuum tube? Well, the tube already contains superconducting cable and rings. Powell and Maise realized that the tube could be magnetically levitated to this altitude. If we arrange that there is a superconducting cable on the ground carrying 200 million amperes, and a superconducting cable in the launch tube carrying 20 million amperes, at an altitude of 20 km there will be a levitating force of about 4 tons per meter of cable length - more than enough to levitate the launch tube.

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Sandia National Laboratories has carried out a '"murder-squad" investigation of the Startram concept, whose purpose is to find any flaw in a proposed project. They gave Startram a clean bill of health. Estimates suggest that building a passenger-capable Startram would require 20 years and a construction budget (ignoring inflation and overoptimism) of about $60 billion.

Why take on such an enormous project? Simple - $50 per kilogram amortized launch costs. The total worldwide cost of developing and using rocket-based space travel is more than $500 billion. The Space Shuttle program cost about $170 billion. The International Space Station has cost about $150 billion to date. As yet, we are making very little commercial use of near-Earth space beyond deployment of communication and imaging satellites. Reducing the LEO insertion costs a hundredfold should finally start our commercial exploitation of the special resources of space. Not to mention making orbital hotels a travel goal for middle-class tourists!