Starting from a few hundred meters, a challenging approach to a few dozen meters was successfully exercised last week. Not really an autonomous rendezvous though: the main objective was rather to collect relevant experience at mid to close range.
Rendezvous with BEESAT-4
At this distance, the vision-based navigation system has indeed to face three major problems:
Some reliabilities problems on the spacecraft have prevented us to perform this approach autonomously (these problems will be solved soon with a software patch of the AOCS). As a consequence, this approach has been performed with the ground segment in the loop, resulting in a pretty large control cycle of about 12 hours (time necessary to download the images, process them, compute a new guidance plan and upload it to the spacecraft). Nevertheless, we were able to reduce the separation by less than hundred meters and we are glad to recognize BEESAT-4 in one picture: its cubic shape together with its two antennas (check it here) are now clearly visible! This is the ultimate proof that we were following the proper object.