Since this is a form of applied ethics, I think is is hard to track down a separate branch, if not with more or less generic terms as futurology like suggested by Conifold. The authors in the field rarely refer to themselves as futurologists though, so terms like these bear limited utility. The topics are mostly handled within branches of applied ethics as various as philosophy of medicine, technology, culture, or the like.
Therefore, what you would have to do is to look for some typical topics - which involve a potential ethical problem, like human-machine communications, space colonisation, or genetic engineering. There, ethical implications are often discussed and some form of stance is taken since exploring them is the motivation for most works on these topics.
One source that directly comes to (my) mind is this book edited by Jules de Mul:
http://demul.nl/en/publications-3/select-publication-catagory/books/item/376-artificial-by-nature-plessners-philosophical-anthropology-perspectives-and-prospects
The perspectives are based on a particular philosophical conception of the human, though, so it can be confusing at times.
I guess your best bet if you want to find systematic exploration of what humanity as a whole should strive for is philosophical anthropology, since they inquire the human condition and often this involves some discussion of what is appropriate to it and what is not.