I recently learned about the Orbiting Astronomical Observatories (OAO) program, a series of four space telescopes, the first launched already in 1966. Only two made it to orbit and entered operational phase. This program can be considered as a precursor program up to what would become the Hubble Space Telescope, aimed to show what is possible and gathering support for the big HST.
Being spoiled by HST images and now JWST images, I think of pretty pictures when I think of space telescopes. However, I don't think the OAO's had the capability to produce data from which images could be constructed. From the instrument description of the last of the OAOs (Copernicus) I gather that these telescope had a "single pixel" kind of instrument, which would be pointed at a source of interest and the e.g. collect the spectrum of incident light. I found two data archives for Copernicus (MAST and HEASARC), but I don't have the skills to process that data into anything meaningful.
What was the first space telescope that could produce something that could be classified as a picture?
I'm willing to interpret "picture" loosely: a collection of data points, evenly spaced in a grid-like pattern that is fine enough to discern features of the observed object.