AAReST was a really neat project by Caltech and University of Surrey (UK) to experiment with a self-assembling space telescope mirror. There are some interesting articles and papers about it circa 2015, but nothing since then.
Curious to know if it is going to get launched.
Some links:
http://weebau.com/satellite/A/aarest.htm
https://directory.eoportal.org/web/eoportal/satellite-missions/a/aarest