If you're interested in a critical review of FOCAL (which is also rather interesting) - https://arxiv.org/pdf/1604.06351.pdf https://arxiv.org/pdf/1604.06351.pd

If you're interested in a critical review of FOCAL (which is also rather interesting) - https://arxiv.org/pdf/1604.06351.pdf https://arxiv.org/pdf/1604.06351.pdf I am on the "this is a really hard problem - but an interesting one" category. It seems like it will take a number of significant improvements on top of current technology - but it seems like it would be doable in another few decades if we continue to improve (the difference between Pioneer and New Horizons is 35 years... if we can do that much improvement again we might have something). It is still something that if you are a grad student working on it now, it would launch when you retire, and your grad students when you retire - when they retire, it is their grad students who would be doing analysis of the data. I tend to believe this would be a good thing to do because it would be working on that time frame and getting us to think about projects that will run for a century rather than a budget cycle.