This article is rated Stub-class on Wikipedia's content assessment scale. It is of interest to the following WikiProjects: | |||||||||||
|
It might be considered useful to present the relationship, for the optimal orbit around a spherical asteroid, between the acceleration achieved, the radius of the asteroid, and the mass of the tractor. I believe that I can provide this (assuming the asteroid to greatly outweigh the tractor), but it would need checking. 82.163.24.100 (talk) 19:14, 31 March 2009 (UTC)
The tidal forces are indeed small; but at the maximum they are larger than the average propulsive force. The tractor is a heavy object near to the asteroid's surface. One should consider whether surface material can be lifted; at least for likely masses, it seems not. 82.163.24.100 (talk) 11:55, 6 April 2009 (UTC)
As far as I can see, a gravitational tractor is just another name for the gravity tractor. Therefore, I suggest it to merge into one article. Any (other) opinions? EmilTyf (talk) 23:55, 19 May 2009 (UTC)
I completely agree with Kingdon's edit summary for edit 345033626 - the clause added in the previous edit was awkwardly worded and not very helpful. However, Patrick is correct that the fate of the reaction mass is a big issue for a hovering tractor. Wouldn't the exhaust slamming into the target (towed) object impart a force in the opposite direction of the (already minuscule) pull of the tractor? I don't know the numbers, but that's got to be a significant hurdle if not an outright negation of the intended delta-v.
I am therefore adding a paragraph under the Limitations section describing this problem. If my reasoning is wrong, please discuss here. ☯ Z.S. ☠ 17:16, 17 March 2010 (UTC)
"According to Rusty Schweickart, the gravitational tractor method is also controversial because during the process of changing an asteroid's trajectory the point on Earth where it could most likely hit would be slowly shifted across different countries. It means that the threat for the entire planet would be minimized at the cost of some specific states' security. In Schweickart's opinion, choosing the way the asteroid should be "dragged" would be a tough diplomatic decision."
There was a Superman comic-book story in which a Metropolis scientist had discovered an asteroid headed for the Earth, that would hit (note that I did not say impact) Metropolis in a week's time (or so). How could he have possibly have known what path the asteroid would take once it entered the atmosphere? He might be able to predict within a thousand miles or so, but I bet he'd have trouble coming even that close.
Furthermore, it's assumed that whatever method is used to deflect the object will be sufficient to guarantee its missing the Earth altogether, and by a wide margin -- or why bother? WilliamSommerwerck (talk) 19:04, 8 December 2013 (UTC)
I'm confused about why the asteroid is going to be on impact trajectory at one point... That sounds like a terribly inefficient orbit adjustment. Then again, I'm no rocket scientist. 7yl4r (talk) 03:03, 16 April 2014 (UTC)
There is no mention of the rather major time and energy requirements required to radically change course in order to match velocities to rendevous with the target. The discussion needs to be made of rendezvous versus direct intercept on a near reciprocal trajectory or an with an impactor or a nuclear payload. For a given mass of launch vehicle and fuel, a considerably larger payload is possible with an impactor/nuclear payload. For an impactor, the extremely high closing velocity and impact energy adds to the expected reaction impulse. With this in mind, if given a limited time to impact, high closing velocity, or trajectory requiring an extreme reversal of trajectory (and expenditure of fuel), any method requiring rendevous including gravity tractors may be non-viable. Pmarshal (talk) 10:07, 22 December 2021 (UTC)