Spacecraft
that need to fly in formation could use superconducting magnets rather than
using reaction mass. Two groups of researchers are working on technology that
could replace old-fashioned thrusters, which use jets of gas and Newton's Third Law.
The problem with using thrusters is that the reaction mass
is ejected to provide the effect; spacecraft can carry only a limited amount of
material into orbit. Once the reaction mass is gone, the craft is left without
a means of maneuvering. Spacecraft could orient
themselves with each other using electromagnets.
David Miller of MIT's Space Systems Laboratory is testing
the idea using devices that float on a glass plate by blowing air down onto it
to simulate the weightlessness of space (see video).
In spacecraft, arrays of solar cells would provide power for
electromagnets.
This method is not without problems; strong magnetic fields
could disrupt delicate electronic equipment. However, shielding can be used in
most cases; also, small secondary electromagnets could be used to cancel the main
field in small areas.
This technique could run into problems in Earth orbit; the
Earth's powerful magnetic field would pull on the magnets, causing spacecraft
to begin spinning. However, a group led by Shin-ichiro Sakai of the Japan
Aerospace Exploration Agency (JAXA) thinks this problem could be solved by
switching the polarity of the magnets several times per minute, achieving a
delicate balance.
We all remember how fleets of spacecraft are shown
"parked" in formation (remember the "rag
tag fleet" of Battlestar Galactica); this technology could provide a
way for spacecraft to fly in formation without expending fuel needed for
maneuvering.
Via Magnets
help spacecraft stick together.
(This Science Fiction in the News story used with
permission of Technovelgy.com)
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