I downloaded the most recent zip file from https://cddis.nasa.gov/archive/doris/products/orbits/ssa/s6b/. The exact file is ssas6b30.b26133.e26143.DG_.sp3.001.Z
There isn't a space between the first and second velocity components for every single velocity listed, which causes the python SP3 library to throw an exception when attempting to read from it. This file should be edited and reuploaded.