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Mega electrovoltaic sail - go for testing


PB666

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1 hour ago, PB666 said:

https://www.nasa.gov/centers/marshall/news/news/releases/2016/nasa-begins-testing-of-revolutionary-e-sail-technology.html

I estimated this might create a  millinewton of thrust, at 1 AU. more at mercury, much less beyond Jupiter.

Steering is applied by shifting the voltages of the wires.

 

 

Could it accelerate to .01 to .03 c?

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Also, ever since Starshot was announced, there has been 2 new propulsion systems that are being funded, this, and a fusion drive (I put that up here already, see page 1 or 2), do you guys think that Starshot was the thing we needed to really study the possibility of interstellar travel? I mean, I know there are countless papers on it, but it seems like we're really getting serious about it.

Hopefully the flame doesn't die.

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2 minutes ago, Spaceception said:

Also, ever since Starshot was announced, there has been 2 new propulsion systems that are being funded, this, and a fusion drive (I put that up here already, see page 1 or 2), do you guys think that Starshot was the thing we needed to really study the possibility of interstellar travel? I mean, I know there are countless papers on it, but it seems like we're really getting serious about it.

Hopefully the flame doesn't die.

The name of the project seems to give away enough, I think.

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9 minutes ago, Spaceception said:

Could it accelerate to .01 to .03 c?

i calculated the maximum accelertation of  a 1 ton craft would be around .001 m/s

That is actually pretty good for an solar driven ion drive. When leaving earth if it it is fired retrograde/radial  solar relative and then pushes radial it might be able to obtain a venus crossing orbit, it could pick up mercury level protons and use that to push out an extremely elliptical orbit. At mercury it could generate .01 m/s and near periapsis even use oberth in and out of the mercurial orbit. 

mercury moves at 47.3 km/sec, dropping down to that orbit from 1AU would be i suspect 60 km/sec, ipads are not conducive to doing orbital mechanics, in any case if you can spend 5 days, 438,000 secs, at 0.01 m/s adds 4380 dv on top of this, to increase speed, its possible that adding that would add 20,000 maybe 40000 dv within venus orbits and another 30000 from venus to earth, its not ideal, because you are not at periapsis, but the space craft would be moving at plutos orbit double or triple the voyager speed. 

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10 hours ago, Spaceception said:

Could it accelerate to .01 to .03 c?

I think it couldn't go faster than the solar wind protons? 'Only' about 600 km/s => 0.002 c. Oh but maybe it's good for breaking at the other end?

Edited by DBowman
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1 hour ago, DBowman said:

I think it couldn't go faster than the solar wind protons? 'Only' about 600 km/s => 0.002 c. Oh but maybe it's good for breaking at the other end?

The limit is the wire mass, if the wires and tethers could be made very thin then you coukd reduce the weight of the wire sail and it could accelerate faster. We are talking about needing a coverager of 400 sq. km for a kilogram payload. I dont see this going over 100000 m/s. If you wanted to carry humans we are talking about 10000 times that area or more. On the bright side if you were traveling to ac there is the potency that you could turn the device around and slow down, because now the protons are moving at the wires at 50000000 m/s, they have alot more energy and they will get much closer to the wire allowing more propulsion, problem is that as protons get way out in space they tend to recouple with electrons and chill out. 

If you could hold the device at mercurial orbit for a year and release it, it could go half solar wind speed, barring my wild experiment with quantum gravity, i don't see this happening. 

When the fastest thing you have managed to accelerate is 15km/sec at plutos orbit and is basically a fifty year old speed limit, doubling that speed is a significant break through. 

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@DBowman ask if the solar wind travels at 600km/s then that is your max speed?  
I guess it is.. Unless you have a high energetic solar flare with photons close to the speed of light, but it would not be enough time to increase your speed much.

They seem easy to deploy and cheap..  but I guess the wires should be covered with a reflective layer, so you can use superconductivity to keep the charge without waste extra energy and keep the wires diameter thin to improve thrust/mass ratio.
About your final speed @PB666 , not sure if I am wrong of technology or you are.

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