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Hypothetical Question : EDM in Space ?

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(@pdop-10)
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Wondering if you were to use a Total station in space or say the moon ( hypothetical of course) would it work and what sort of adjustments would need to be made to the measurements if you were measuring distances ?

I started thinking well there is no atmosphere, low temperatures, different gravitational forces and really bad solar radiation, I would be surprised if it would work at all.

Any ideas on if it would work and if so, what sort of results you would get ?

And No, I am not planning on signing up for the mars mission B-)

PS : I know for sure you could not use a plumb bob, although I have never used one since I started in 1986 anyway. ( no dis to all you plumb bob users out there though :-O )

 
Posted : July 19, 2013 11:21 am
(@kent-mcmillan)
Posts: 11419
 

> Wondering if you were to use a Total station in space or say the moon ( hypothetical of course) would it work and what sort of adjustments would need to be made to the measurements if you were measuring distances ?

Well, you'd have to use a much different refraction correction than would be needed on Earth since the index of refraction on the lunar surface is very nearly 1.0000000 instead of the much different values through air. I don't know whether you're aware of this or not, but one of the Apollo missions left a bank of retro-reflecting prisms on the Moon off of which astronomers at the McDonald Observatory in West Texas were able to bounce a laser beam and measure the distance to the Moon. That may be the longest EDM measurement made to date.

 
Posted : July 19, 2013 11:31 am
(@goddsc)
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That is cool stuff, Kent. I have been to the McDonald Observatory in the Davis Mountains, but unfortunately it was on a night when there had been severe summer thundershowers and the clouds hadn't totally cleared yet. Pretty darn dark up there.

 
Posted : July 19, 2013 11:39 am
(@kent-mcmillan)
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Here's a link to the Wiki entry for the Lunar Ranging Experiment.

 
Posted : July 19, 2013 11:43 am
 trah
(@trah)
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May be possible to take it even one step further...

Interplanetary precision laser could reach to Mars and beyond

 
Posted : July 19, 2013 2:02 pm
(@holy-cow)
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Believe it or not, the geniuses on Big Bang Theory were shooting a laser to the moon on one episode so they could have it reflect off of one of those prisms.

 
Posted : July 19, 2013 2:03 pm
(@dave-lindell)
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And why couldn't you use a plumb bob, except for not knowing how?

 
Posted : July 19, 2013 2:36 pm
(@loyal)
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Agree with Dave.

If you can stand on it (any extraterrestrial object), then a plumb bob will work fine. It might take awhile to "settle down" (on say an asteroid), but it WILL be normal to local gravity (point "down").

B-)
Loyal

 
Posted : July 20, 2013 6:21 am
 jud
(@jud)
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I have one that would work. AGA 76, laser, for those distances knowing the proper 2000 meter segment would be a challenge, the wave repeats every 2000 meters.
jud

 
Posted : July 20, 2013 7:09 am
(@spledeus)
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I want to see an astronaut using a plumb bob. Let's call NASA.

After they are done with that, they can churn some butter by hand and get the rover moving with a buggy whip.

 
Posted : July 20, 2013 9:08 am
(@dave-lindell)
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The original comment was "I know for sure you can't use a plumb bob..."

I didn't think you should.

 
Posted : July 20, 2013 2:55 pm
(@spledeus)
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I was just being impish. There's a time and a place for such equipment. In the hands of a true master, the Bob is a great tool. In my hands, it makes for a great pendulum.

Besides, they limit the weight on those rockets and unless there was a real need for a hunk of brass, they would not waste the space or fuel for a Bob In Space...

 
Posted : July 21, 2013 12:36 pm