{"action":"closed","issue":{"url":"https://api.github.com/repos/MuMech/MechJeb2/issues/155","labels_url":"https://api.github.com/repos/MuMech/MechJeb2/issues/155/labels{/name}","comments_url":"https://api.github.com/repos/MuMech/MechJeb2/issues/155/comments","events_url":"https://api.github.com/repos/MuMech/MechJeb2/issues/155/events","html_url":"https://github.com/MuMech/MechJeb2/issues/155","id":16222630,"number":155,"title":"[Suggestion] Changing LambertSolver","user":{"login":"fibonatic","id":1704374,"avatar_url":"https://avatars.githubusercontent.com/u/1704374?v=3","gravatar_id":"","url":"https://api.github.com/users/fibonatic","html_url":"https://github.com/fibonatic","followers_url":"https://api.github.com/users/fibonatic/followers","following_url":"https://api.github.com/users/fibonatic/following{/other_user}","gists_url":"https://api.github.com/users/fibonatic/gists{/gist_id}","starred_url":"https://api.github.com/users/fibonatic/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/fibonatic/subscriptions","organizations_url":"https://api.github.com/users/fibonatic/orgs","repos_url":"https://api.github.com/users/fibonatic/repos","events_url":"https://api.github.com/users/fibonatic/events{/privacy}","received_events_url":"https://api.github.com/users/fibonatic/received_events","type":"User","site_admin":false},"labels":[],"state":"closed","locked":false,"assignee":null,"milestone":null,"comments":5,"created_at":"2013-07-01T16:23:45Z","updated_at":"2015-06-02T21:25:08Z","closed_at":"2015-06-02T21:25:08Z","body":"I am not 100% sure how the LambertSolver calculates the position change within a certain change in time. However I recently worked on an equation which gives the change in time depending on the change in position: http://physics.stackexchange.com/questions/69380/what-are-common-methods-for-calculating-the-time-dependency-of-elliptical-orbit\r\nSo the opposite of of what this does. Unfortunately there is no inverse function of this equation, however with newton or secant method it could be done. I am not sure if this would be faster than this LambertSolver, but I would suspect it would since you have an exact equation.\r\n\r\nI have confirmed this equation for both circular, elliptical and hyperbolic orbits (e=0, 0<e<1, e>1), however for a parabolic orbit it does not (e=1)."}}