The only practical approach I can think of for combating the constellations is distributed arrays of wide-field transient-hunters. As long as the transient is common-mode across telescopes, then it is real. If there are three LSSTs, and not too many constellation-satellites, that might work.
I just noted, in passing, that the term for the satellite arrays appears to be "constellation"; that is a bummer in this context.
Some documents that might be of interest, pretty hot off the press:
- "Mitigation of LEO Satellite Brightness and Trail Effects on the Rubin Observatory LSST" https://arxiv.org/abs/2006.12417
- "Mitigation of Satellite Tracks in LSST Data Processing" - https://aas.org/sites/default/files/2020-07/MitigationWG_Pre...
There are some good techniques available, and the very smartest experts on image processing are working on this task, so I think we'll manage.