  Very long baseline interferometry (VLBI) from the ground at millimeter
wavelengths can resolve the black hole shadow around two supermassive black
holes, Sagittarius A* and M87. The addition of modest telescopes in space would
allow the combined array to produce higher-resolution, higher-fidelity images
of these and other sources. This paper explores the potential benefits of
adding orbital elements to the Event Horizon Telescope. We reconstruct model
images using simulated data from arrays including telescopes in different
orbits. We find that an array including one telescope near geostationary orbit
and one in a high-inclination medium Earth or geosynchronous orbit can
succesfully produce high-fidelity images capable of resolving shadows as small
as 3 microarcseconds in diameter. One such key source, the Sombrero Galaxy, may
be important to address questions regarding why some black holes launch
powerful jets while others do not. Meanwhile, higher-resolution imaging of the
substructure of M87 may clarify how jets are launched in the first place. The
extra resolution provided by space VLBI will also improve studies of the
collimation of jets from active galactic nuclei.
