A compact celestial tracker includes a platform, a rotation stage that rotatably coupled to the platform to rotate a plane of the platform about a rotation axis and that supports the platform on a substrate, an off-axis parabolic mirror mounted to one side of the platform and having a focal plane directed at an acute angle that is between the rotation axis and the plane of the platform to reflect and focus the beam at a point above another side of the platform, and a detector coupled to the other side of the platform to receive and detect the reflected and focused beam.