A team at NASA is testing a chemical-free propulsion system that will use Earth?s magnetic field to move satellites and spacecraft in orbit.
Space tethers collect current when they fly near the ionosphere - the charged, upper layer of atmosphere - and magnetic field. The current flowing through the wire will be pushed on by Earth?s magnetic field, creating a force that can be used to raise or lower a spacecraft?s orbit.
Currently, satellites in Earth?s orbits have to periodically re-boost themselves owing to constant degradation of their orbits due to friction from colliding with atmospheric particles. The satellites have a limited supply of fuel for thruster rockets. When the gas runs out, the spacecraft?s days are numbered.
A tether could lower a satellite?s orbit so that it could, for example, more quickly re-enter Earth?s atmosphere at the end of its operational life and avoid becoming another piece of space debris.
?We want to demonstrate a tether propulsion system that someone can just go and copy it, and fly it,? Discovery News quoted Les Johnson at NASA, as saying.
?We really are interested in casting a wide net. We?re not going to specify the precise technology to be demonstrated,? NASA?s chief technology guru Bobby Braun said.
