Submitted for Presentation at SPESIF-2010 - Space, Propulsion, and Energy Sciences International Forum
February 23, 26, 2010
John Hopkins Applied Physics Laboratory
Maglev Launch: Ultra Low Cost Ultra/High Volume Access to Space for Cargo and Humans
James Powella, George Maisea and John Ratherb
Abstract. Despite decades of efforts to reduce rocket launch costs, improvements are marginal. Launch cost to LEO for cargo is ~$10,000 per kg of payload, and to higher orbit and beyond much greater. Human access to the ISS costs $20 million for a single passenger. Unless launch costs are greatly reduced, large scale commercial use and human exploration of the solar system will not occur. A new approach for ultra low cost access to space – Maglev Launch – magnetically accelerates levitated spacecraft to orbital speeds, 8 km/sec or more, in evacuated tunnels on the surface, using Maglev technology like that operating in Japan for high speed passenger transport.
The cost of electric energy to reach orbital speed is less than $1 per kilogram of payload. Two Maglev launch systems are described, the Gen-1System for unmanned cargo craft to orbit and Gen-2, for large-scale access of human to space. Magnetically levitated and propelled Gen-1 cargo craft accelerate in a 100 kilometer long evacuated tunnel, entering the atmosphere at the tunnel exit, which is located in high altitude terrain (~5000 meters) through an electrically powered “MHD Window” that prevents outside air from flowing into the tunnel. The Gen-1 cargo craft then coasts upwards to space where a small rocket burn, ~0.5 km/sec establishes, the final orbit.
The Gen-1 reference design launches a 40 ton, 2 meter diameter spacecraft with 35 tons of payload. At 12 launches per day, a single Gen-1 facility could launch 150,000 tons annually. Using present costs for tunneling, superconductors, cryogenic equipment, materials, etc., the projected construction cost for the Gen-1 facility is 20 billion dollars. Amortization cost, plus Spacecraft and O&M costs, total $43 per kg of payload. For polar orbit launches, sites exist in Alaska, Russia, and China. For equatorial orbit launches, sites exist in the Andes and Africa. With funding, the Gen-1 system could operate by 2020 AD.
The Gen-2 system requires more advanced technology. Passenger spacecraft enter the atmosphere at 70,000 feet, where deceleration is acceptable. A levitated evacuated launch tube is used, with the levitation force generated by magnetic interaction between superconducting cables on the levitated launch tube and superconducting cables on the ground beneath. The Gen-2 system could launch 100’s of thousands of passengers per year, and operate by 2030 AD. Maglev launch will enable large human scale exploration of space, thousands of gigawatts of space solar power satellites for beamed power to Earth, a robust defense against asteroids and comets, and many other applications not possible now.
Keywords: Maglev, space launch, superconductor.
PACS: 74, 88, 0287+V
I. GOING BEYOND ROCKETS
Space exploration and commerce have been limited by the high cost of launching people and payloads into orbit and beyond. Placing a kilogram of payload into low Earth orbit (LEO) costs almost $10,000, while a human at the International Space Station costs 20 million dollars. Payloads to GEO costs an order of magnitude more, while to the moon and Mars, the costs are much greater still.
Over the last 40 years, efforts to develop lower cost launch systems, including fully reusable launch vehicles, scramjets, single stage to orbit, etc have failed. No realistic approaches for large reductions in launch costs, using chemical propellants, have been found.
The recent NASA panel on the future of NASA’s Constellation program recommends not proceeding with the proposed return to the Moon. The high cost and complexity of rocket launch appear to rule out affordable and effective human exploration of space beyond the ISS.
II. startram – A NEW ROAD TO SPACE
The energy cost to deliver payloads to orbit is tiny, if directly applied to the payload itself. At 8 kilometers per second, the kinetic energy of a kilogram of mass is only 32 megajoules, or 8.9 kilowatt hours. At 6 cents per KWH, the average US electrical production cost, this is only 53 cents per kilogram of payload – 10,000 times smaller than present launch costs. On an airless planet, launching heavy payloads into space would be incredibly cheap and easy.
Using Maglev (Magnetic Levitation), heavy vehicles are magnetically levitated above a guideway without mechanical contact or friction, and magnetically propelled at high speeds. Maglev systems already operate in Japan and other countries for passenger transport and levitate hundreds of tons. Vehicle speeds of 360 mph are achieved, limited only by air drag. In low pressure tunnels, vehicle speed is virtually unlimited. Instead of rockets, the startram system magnetically levitates and accelerates spacecraft to orbital speeds, ~8 km/sec, in evacuated tunnels in elevated terrain. They then enter the atmosphere at reduced air density, and coast upwards to orbit. A small ΔV burn by a compact, attached rocket finalizes the spacecraft’s orbit.
Conventional rockets locate their expensive, complex equipment on the launch vehicle. startram locates its expensive, complex equipment on the ground. With a simple low cost launch craft, startram reuses its ground equipment for many launches. World rocket launches are only a few hundred tons of payload annually.
A single startram facility can launch hundreds of thousands of tons of payload per year, at a cost of only $50 per kilogram. startram will vastly increase space exploration and commerce, including manned bases on the moons and Mars, exploration of the moons of the giant planets, interstellar probes, multi-gigawatt space power satellites that beam power to Earth, space hotels and tourism, space manufacturing, worldwide continuous environmental monitoring, high bandwidth communications, etc. A single startram facility could deploy 100 gigawatts(e) of space solar power satellites per year at a launch cost of only 200 dollars per KW(e), a small fraction of Earth based power plant costs.
In only a decade 1 billion KW(e) of space solar power could be deployed, a third of the World’s need. With only 3 startram launch facilities, all of the World’s electric power needs could be met by space solar power in just 10 years.
Please read the rest of this analysis which was based on the original Star Tram research paper here.