From: Goddard Space Flight Center
Posted: Wednesday, May 4, 2005
"Are we there yet?" Everyone has faced this exasperating question from impatient companions on a long road trip. Imagine if the trip lasted six months. One way.
It takes conventional rockets about six months just to get to Mars. Total roundtrip times can be as long as three years, because an extended stay on the Red Planet is required while the Earth and Mars progress in their orbits enough to be closely aligned again for the return trip.
But an exciting NASA-funded research project could send astronauts racing to Mars up to six times faster. The solution -- proposed by Dr. Robert Winglee of the University of Washington -- sounds like science fiction. A spacecraft rides a beam of plasma, which is electrified and magnetized gas, all the way to Mars and back. The roundtrip journey could be wrapped up in about 90 days using Winglee's Magnetized Beam Plasma Propulsion system, dubbed Magbeam.
How It Works and Where It Came From
The system would use space stations to generate the plasma and beam it to a spacecraft. The spacecraft generates its own magnetic field, which deflects the plasma beam. Like wind pushing on an umbrella, the deflection of the plasma beam generates a force that propels the spacecraft. Another space station orbiting the destination generates a beam to slow down the spacecraft upon its arrival, and to launch it on the return journey.
Next Stop, The Red Planet
A typical Mars mission would begin as Earth and Mars are approaching the point of closest alignment as they progress in their orbits, with the Earth slightly behind Mars. A conventional rocket first launches the target spacecraft into orbit around Earth. The Magbeam station would fire a plasma beam at the target spacecraft for about four hours, giving it a boost toward Mars. The spacecraft coasts to Mars in about 50 days, after which another station in orbit around Mars fires a plasma beam at the spacecraft to slow it down.
The spacecraft goes into orbit around Mars and the astronauts descend to explore the surface. After 11 days, they launch to Mars orbit, where the Martian station fires its plasma beam again to accelerate the spacecraft toward Earth. After coasting toward Earth, the station in orbit around Earth fires its plasma beam at the spacecraft to capture it in Earth orbit.
If the challenges can be overcome, the Magbeam system will offer several benefits: First, a fast trip to Mars will reduce the space radiation hazard to astronauts. High-speed particles from the Sun and interstellar space continually bombard any spacecraft traveling between planets. However, this space radiation can be deflected by planetary magnetic fields or absorbed by a planet's atmosphere. Getting astronauts quickly from one planet to another will reduce their exposure to space radiation. The high-speed makes Magbeam useful for missions beyond Mars as well, "We think this would be a good system for delivering payloads to Jupiter and beyond," said Winglee.
Research into this radical design is being funded by the NASA Institute for Advanced Concepts (NIAC). NIAC was created in 1998 to solicit revolutionary concepts that could greatly advance NASA's missions from people and organizations outside NASA. The proposals push the limits of known science and technology, and thus are not expected to be realized for at least decade or more. NIAC's intention is to discover ideas which may result in beneficial changes to NASA's long-range plans. The Universities Space Research Association operates NIAC for NASA.
More about Magbeam (PDF document) http://www.niac.usra.edu/files/library/meetings/fellows/mar05/1012Winglee.pdf
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