 Driven by the need for better data, the technique that rotates the telescope during observations called spatial scanning was developed by the Hubble team. The technique was demonstrated with a pilot program of spatial scanning observations of the open star cluster M35 in 2009. Normally, angles on the sky between objects as well as other information about each object were based on a static photograph. Telescope jitter and pixel saturation limited the amount and accuracy of the collected data. By rotating a telescope during observations, each point image is replaced by a line, a trail, on the detector. The trails for all sources are parallel in the frame. We see that the light from each source is spread over a much larger number of pixels. Furthermore, each long trail provides thousands of separate position measurements in the cross-trail direction and one for each pixel traversed, thus averaging out the impact of single pixel and local telescope jitter irregularities. With spatial scans, Hubble can achieve measurement precision of a parallax angle of 40 micro arc seconds. This translates into distance measurements as far as 80,000 light years away. This is close to what the Gaia satellite can do and has enabled Hubble to measure distances to the stars out to the Milky Way halo.