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  • [MUSIC]

  • What is electric propulsion or ion propulsion?

  • Electric propulsion is the use of electrical energy off a satellite to accelerate a gas

  • and then create thrust.

  • Our nation has gone to a global, space-based infrastructure.

  • If you receive Sirius XM Radio or Direct TV, it's provided by a satellite 20,000 miles

  • above you.

  • And that satellite has to be positioned directly above you at all times.

  • However, we can't hold a satellite perfectly still and the earth is not perfectly round,

  • so it tends to drift over time and we need a propulsion system to hold that satellite

  • in position above you at all times.

  • Traditionally, we provide the propulsion with chemicals.

  • That is, we mix a fuel and oxidize it together.

  • We get a high pressure, high temperature fire, just like you see on the Space Shuttle, and

  • that's how we hold the satellite in position.

  • The problem is that eventually, that satellite runs out of fuel, and when it's out of fuel,

  • the satellite is effectively dead.

  • We've overcome that limitation with electric propulsion.

  • By using electricity off the satellite, we can simply turn up the voltage on the engine,

  • increase the efficiency, and now we get more miles per gallon for the fuel on that satellite.

  • We use that capability to make the same satellite with the same performance, but with less propellant,

  • which means a smaller satellite.

  • We can now launch several small satellites off of a single launch vehicle.

  • This reduces the cost of putting that satellite on orbit and eventually reduces the cost of

  • beaming the information to you.

  • So, what is the impact of electric propulsion on your life?

  • It actually reduces the cost of getting information beamed to you from space.

  • [MUSIC]

[MUSIC]

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B1 中級

TECH+知識+Y:什麼是電力推進? (TECH + knowledge + Y: What is electric propulsion?)

  • 109 16
    richardwang 發佈於 2021 年 01 月 14 日
影片單字