add to /etc/apt/sources.list.d deb http://apt.nick-strauss.com/apt/debian jessie main then, you can update and get orbtimes as, apt-get update; apt-get install orbtimes then, man orbtimes and orbtimes.
orbtimes-1-5-tar This is strictly an alpha test. Released under the GNU free software license. * Copyright (C) 2017 Nicholas C. Strauss (firstname.lastname@example.org) This file is part of ORBTIMES. This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as […]