rectilinear orbit

Noun

 * 1) A theoretical type of  which goes in a straight-line, up and down; with 100%  (=1.0); the orbital path passing through the center-of-mass of the primary mass being orbited; having an  at 0, and two, as both arms going out from the periastron are equidistant; where the orbital  has zero width /, and the path of the ellipse is the same as the.