--- donna <maio1@...> wrote:
> To: "RadarMatrix2003"
> <RadarMatrix2003@yahoogroups.com>
> From: "donna" <maio1@...>
> Date: Thu, 10 Jul 2003 13:33:59 -0400
> Subject: [RadarMatrix2003] Earth's ionosphere is a
> vast, unbounded laboratory
>
> Im no Rocket scientist, but I imagine Star wars to
> have something to do with this tether system.
>
>
>
http://liftoff.msfc.nasa.gov/Shuttle/sts-75/tss-1r/brochure/page_i.html
> Scientists study plasma for practical purposes. In
> an effort to harness fusion energy on Earth,
> physicists are studying devices that create and
> confine very hot plasmas in magnetic fields.
>
> The TSS-1R investigators will study the
> electrodynamic properties of a tethered satellite
> system and its interaction with Earth's ionospheric
> environment of charged gas (plasma) and magnetic and
> electric fields. The motion of the Tethered
> Satellite System through Earth's magnetic field
> generates a voltage across the conductive tether. As
> a result, the TSS is able to extract an electrical
> current from the ionospheric plasma at the satellite
> and to emit that current by means of electron
> accelerators in the payload bay. Investigators will
> be able to vary this current and control the
> electrical potential of the satellite to create and
> study a variety of phenomena and processes. These
> include electric power generation, wave generation
> and propagation, neutral gas ionization, and basic
> physical processes that occur naturally in plasmas
> surrounding Earth and other planets, moons, and
> comets. Although some of these phenomena have been
> studied in laboratories, the ground-based scientist
> is limited to experimenting on a small scale and is
> hampered by chamber wall effects, unnatural plasma
> distributions, and other problems.
> For the Tethered Satellite System, Earth's
> ionosphere is a vast, unbounded laboratory for space
> plasma experiments that can be conducted in no other
> way.
> A tether system could supply power to an orbiting
> spacecraft, supplementing solar arrays and batteries
> or serving as a backup emergency power system. The
> longer the tether, the higher the electrical voltage
> it will produce. The 20.7-km long tether used in the
> TSS-1R mission will generate up to approximately
> 5,000 volts, while a 96-km long tether could
> generate as much as 15,000 volts. The total amount
> of power produced by the system will depend on orbit
> inclination, conditions in the ionosphere, and the
> capabilities of the satellite to collect electrons.
> One of the questions TSS-1R may help to answer is
> how much current can be extracted from the
> ionosphere.
>
>
>
> the current is carried away from the tethered system
> through the ionosphere by electromagnetic waves.
>
>
>
>
> The TSS-1R tether will be the longest antenna ever
> placed in orbit. It can be used either passively for
> receiving radio waves from other sources or actively
> as a transmitting antenna. To transmit, the current
> passing through the tether may be modulated by
> pulsing it on and off at the required frequency. The
> longer the tether, the lower the frequency at which
> it can radiate waves efficiently. This unique
> ability to produce low-frequency waves makes a
> number of active experiments possible. For example,
> since very-low-frequency radio waves can penetrate
> deeper into sea water than normal radio
> transmissions, they may be used to communicate with
> submerged vehicles.
>


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