Ion propulsion is fine, as long as they don't mess around with that damn Queller Drive...
Posted on 01/18/2006 5:29:02 PM PST by KevinDavis
A new design for an ion engine promises up to 10 times the fuel-efficiency of existing electric propulsion engines, according to tests by the European Space Agency. The new thruster could be used to propel craft into interstellar space, or to power a crewed mission to Mars, ESA says.
Ion engines work by using an electric field to accelerate a beam of positively charged particles – ions – away from the spacecraft, thereby providing propulsion. Existing models, such as the engine used in ESA’s Moon mission, SMART-1, extract the ions from a reservoir and expel them in a single process.
(Excerpt) Read more at newscientistspace.com ...
ping
This suggests the most efficient Solar System engine would be a LASER, filled with hydrogen gas, with a small leak.
The LASER energy would expand the electron shells, and the highly excited atoms, or ions, would exit the vessel with maximum speed.
For an interstellar craft, instead of a drive engine that sounds like a vacuum tube, why not accelerate the reaction mass by a device similar to a synchrotron? Just sling it around faster and faster, and then allow it to leave in the correct direction at an appreciable fraction of the speed of light.
Overall thrust would be even lower, but the reaction mass to thrust ratio would be very favorable.
Ding, ding, ding! Absolutely correct. But also mass. The heavier the ions, the greater the "recoil," as you've already implicitly noted.
This new engine kicks out ions at 210km/sec. Very impressive, but still only 7/100ths of one percent the speed of light.
I look forward to the day when we're able to achieve relativistic speeds in the ion exhaust plume. Boy, will we ever have something then! I'm unaware of anything that will prevent us from doing this someday, in principle. In practice, it's a whole 'nuther story.
I love the science channel.
I may have seen the same show...it was about the spacecraft that went to take pictures of an asteroid and a comet.
Is the Pluto spacecraft powered by an Ionic Air Purifying system from the Sharper Image too?
Ion propulsion is fine, as long as they don't mess around with that damn Queller Drive...
(shrug)
Who is John Galt?
I canna' break the Laws of Physics...
Could we have our own self contained power for our homes and for our cars? Wishing hoping and I believe they've been developed but TPTB[=the powers that be] have stopped their release for yrs & yrs & yrs.
Depends on the application. If your mission requires a lot of delta-V right away, an ion thruster ain't gonna cut it. To get newton-level thrust from an ion thruster takes KILOWATTS of electrical power.
I should have pinged you to post 44. Synchrotron drive system, why not?
It really doeesn't matter how much power is required, or used, in the spacecraft, as long as we don't run out of fissionable materials.
What matters is how much reaction mass we have available to throw overboard, and how fast we can sling it.
Of course, you also have to slow down at the end of your journey, unless there's a way to apply a magnetic brake of some sort.
Sometimes you need to get your delta-V quickly because there's something about your mission that won't tolerate long burns. A rendezvous mission, for example, or a moon lander.
You'll note in 44 that I intended such devices for interstellar purpose. The minuscule thrust would be too puny to be useful in-system.
I find it ironic that the ion thruster described in the article sounds so much like an electronic tube without a glass enclosure, i. e. vacuum tube, especially since what seems most promising to me as a means of achieving fusion can be described as an analogue of a vacuum tube, with magnetic force replacing electrostatic attraction or repulsion. It was described in Analog a decade or so ago.
If memory serves, it would be a couple of meters in diameter, with protons flitting back and forth through the center, like moths in search of the street light. Every so often, some of them would collide, hopefully with enough force to stick together.
Vacuum tubes may yet stage a comeback.
Maybe ten years to wait. I'll be pushing 70 then.
Hurry up guys!
2.5 newtons = 0.56 pounds of thrust
But the nice thing is that you can keep it up for a long time
Everything is probably beyond our time. The exciting thing is to be able to consider it.
To actually build something would take a political commitment we are even less likely to see. The only real hope there is that the private sector will be finally unleashed, and then we will see real progress.
Star-drives, as we envision them, will not be able to exceed the speed of light. This is not the problem you might think it is.
If you can get up to an appreciable fraction of the speed of light, and still navigate safely, the journey's time will shrink as you experience it. Those boring and uneventful light-years will become boring and uneventful light-months to you.
Of course the centuries will pass, but it's not as if you expected to return anyway, is it?
Point is, you can go anywhere. You just can't go home again.
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