Talk:Parabolic trajectory

stub

How is this a stub, it is pretty long.Jamesrules90 (talk) 18:53, 10 March 2010 (UTC)

Fixes

I just added the section on Barker's equation (kinda like Kepler's equation but for parabolic orbits). I've noticed that in addition to the page not containing sources, it is also a little repetitive, specifically with the identifications of variables. I'm going to try to clean this up a bit and maybe try to flesh it out. Any help with proofreading, formatting, sources or whatever would be great. Jaxcp3 (talk) 21:00, 4 August 2012 (UTC)

Warning: Barker's equation, as listed at the time of this comment, is incorrect. Do some dimensional analysis on it to see this: left side is a difference of time, which means it is measured in {second}. Right side is a paranthesis of sums of tangents (adimensional) and a square root of {meter^3 * second^(-2) / meter^3}. Which means the right side is measured in {second^(-1)}. This page gives a Barker's equation that is similar to the one here but you'll notice the square root (measured in {second^-1}) multiplies the difference of times there. Bringing it to the other side of the equation requires that it be turned over. Unless someone else fixes this first, I will do so tomorrow, once I learn more about editing wiki eqs.89.137.184.25 (talk) 12:06, 28 May 2013 (UTC)

Capture orbit?

74.111.160.142 (talk) 16:05, 9 October 2015 (UTC)If Newtonian mechanics is assumed and the object does not collide with the central body, how can it be captured? Doesn't the object escape to infinity after it's nearest approach?

An ESA glossary page seems to indicate that this WP page is wrong in defining "capture orbit" this way:

Capture orbit

The first orbit of a spacecraft after it has been captured by the gravitational attraction of a celestial body. The capture is achieved by reducing the speed of the spacecraft. See also Orbit acquisition.

In case that page disappears (it seems to be in disrepair, with header images broken, and bots like the IA archiver are blocked by a robots.txt) see here. —Undomelin (talk) 22:02, 28 June 2018 (UTC)

Hrm, on the other hand, this seems to agree with the definition. "Capture" there seems to be referring not to a notion that the object will be captured on its present course if left to continue along it, but that for the case of an artificial craft, such a path presents a limit to reach -- and once you burn some further fuel to alter the path a bit more (decelerating with respect to the target body), the craft then will be captured. Web searching hasn't turned up yet for me any usage of the terms "capture orbit" or "escape orbit" for natural body cases -- it's always stated in terms of artificial craft that will be subject to thrust and not just gravity alone. I don't see any abstract scientific usage of the terms. The word "orbit" for a parabolic path seems like something of a misnomer. —Undomelin (talk) 22:33, 28 June 2018 (UTC)