  The luminous high-redshift (z=2.17) quasar S5 0836+710 has been observed at
5GHz with the VSOP. We compare the properties of three images obtained from the
observation: a low-resolution ground array image (dynamic range 4600:1), a
full-resolution VSOP image (900:1), and an image made with only the space
baselines (200:1). The space baselines alone are sufficient for a reliable
recovery of the source structure, within the limits of the achieved spatial
sampling of the visibility data. The curved jet ridge line observed in the
images can be described by Kelvin-Helmholtz instabilities developing in a
relativistic outflow with the Mach number of about 6. This description holds on
the scales of up to 700h^-1 pc, and is shown to be consistent with variable
apparent speeds observed in the jet.
