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Astronomy Picture of the Day -- Gravitational Tractor
NASA ^ | July 07, 2012 | (see photo credit)

Posted on 07/06/2012 9:26:10 PM PDT by SunkenCiv

Explanation: How would you change the course of an Earth-threatening asteroid? One idea - a massive spacecraft that uses gravity as a towline - is illustrated in this dramatic artist's view of a gravitational tractor in action. In the hypothetical scenario worked out in 2005 by Edward Lu and Stanley Love at NASA's Johnson Space Center, a 20 ton nuclear-electric spacecraft tows a 200 meter diameter asteroid by simply hovering near the asteroid. The spacecraft's ion drive thrusters are canted away from the surface. The steady thrust would gradually and predictably alter the course of the tug and asteroid, coupled by their mutual gravitational attraction. While it sounds like the stuff of science fiction, ion drives do power existing spacecraft and a gravitational tractor would work regardless of the asteroid's structure or surface properties.

July 07, 2012

(Excerpt) Read more at 129.164.179.22 ...


TOPICS: Astronomy; Astronomy Picture of the Day; Science
KEYWORDS: apod; astronomy; catastrophism; science
[Credit & Copyright: Dan Durda (FIAAA, B612 Foundation)]

1 posted on 07/06/2012 9:26:26 PM PDT by SunkenCiv
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To: brytlea; cripplecreek; decimon; bigheadfred; KoRn; Grammy; married21; steelyourfaith; Mmogamer; ...

2 posted on 07/06/2012 9:29:12 PM PDT by SunkenCiv (https://secure.freerepublic.com/donate/)
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To: SunkenCiv

Of course, catch it in a tractor beam.


3 posted on 07/06/2012 9:30:21 PM PDT by Carthego delenda est
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To: 75thOVI; agrace; aimhigh; Alice in Wonderland; AndrewC; aragorn; aristotleman; Avoiding_Sulla; ...
APoD topic, but relates to asteroid impact threat.



4 posted on 07/06/2012 9:42:14 PM PDT by SunkenCiv (https://secure.freerepublic.com/donate/)
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To: Carthego delenda est

It’ll be the tractor story.


5 posted on 07/06/2012 9:44:19 PM PDT by SunkenCiv (https://secure.freerepublic.com/donate/)
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To: SunkenCiv

Ion Drive sounds great, and this concept would work, if you could just build the ship right in front of the asteroid.

Otherwise, getting the ship ‘to’ an asteroid, and then getting it ‘parked’ in front of it, might require a bit more than an Ion Drive.

Another challenge would be trying to alter the ‘course’ of an asteroid. Although possible, it would take a really, really, really, long time.

Why don’t they just drive an anchor into the asteroid and attach a rope to it ?


6 posted on 07/06/2012 9:45:01 PM PDT by UCANSEE2 (Lame and ill-informed post)
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To: UCANSEE2

7 posted on 07/06/2012 9:47:57 PM PDT by UCANSEE2 (Lame and ill-informed post)
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To: SunkenCiv

If you can deflect an asteroid FROM Earth, you can deflect an asteroid TOWARD Earth.


8 posted on 07/06/2012 9:52:03 PM PDT by DBrow
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To: UCANSEE2
Otherwise, getting the ship ‘to’ an asteroid, and then getting it ‘parked’ in front of it, might require a bit more than an Ion Drive.
Link

The Dawn spacecraft uses ion propulsion to get the additional velocity needed to reach Vesta once it leaves the Delta rocket. It also uses ion propulsion to spiral to lower altitudes on Vesta, to leave Vesta and cruise to Ceres and to spiral to a low altitude orbit at Ceres. Ion propulsion makes efficient use of the onboard fuel by accelerating it to a velocity ten times that of chemical rockets. This efficiency is measured in terms of the specific impulse of the fuel

Another challenge would be trying to alter the ‘course’ of an asteroid. Although possible, it would take a really, really, really, long time.

Given enough time (probably millions of years) and using ever more massive bodies for slingshot maneuvers, we can move planets.

9 posted on 07/06/2012 10:02:28 PM PDT by Moonman62 (The US has become a government with a country, rather than a country with a government.)
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To: DBrow
If you can deflect an asteroid FROM Earth, you can deflect an asteroid TOWARD Earth

Dr Evil, I presume

10 posted on 07/06/2012 10:24:54 PM PDT by ninonitti
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To: DBrow
If you can deflect an asteroid FROM Earth, you can deflect an asteroid TOWARD Earth

Dr Evil, I presume

11 posted on 07/06/2012 10:25:02 PM PDT by ninonitti
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To: SunkenCiv

12 posted on 07/07/2012 4:33:05 AM PDT by left that other site
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To: left that other site

Nothing runs like a Hoyt Clagwell.


13 posted on 07/07/2012 4:45:03 AM PDT by 762X51
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To: UCANSEE2
Why don’t they just drive an anchor into the asteroid and attach a rope to it ?

It might be spinning. You would just have a massive yoyo that winds up the rope and smashes the satellite.

It might be an unstable agglomeration of smaller bits, no good place to put an anchor.

The use of the gravitational link does mean that you can't move small mass asteroids any faster than large ones, which is a problem as you don't generally see them as soon.

Some folks do have interesting work.

14 posted on 07/07/2012 4:54:49 AM PDT by slowhandluke (It's hard to be cynical enough in this age.)
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To: 762X51

Especially when the operator is wearing his “Tractor Driving Suit”!


15 posted on 07/07/2012 5:02:17 AM PDT by left that other site
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To: SunkenCiv

My cousin Marvin’s tow truck could do this for less money. The asteroid has to be in neutral, though.


16 posted on 07/07/2012 6:20:50 AM PDT by blueunicorn6 ("A crack shot and a good dancer")
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To: Moonman62

17 posted on 07/07/2012 8:37:27 AM PDT by Toddsterpatriot (Math is hard. Harder if you're stupid.)
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To: ninonitti

I promise not to deflect a 200 meter asteroid into the Atlantic continental shelf off North Carolina.

If I am properly compensated, I mean.


18 posted on 07/07/2012 11:49:57 AM PDT by DBrow
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