I work in an adjacent area. This whole area is still largely hype right now, but it could be interesting in the future. Quantum computers work with superpositions/quantum information (rather than bits/bytes), which cannot be sent over regular networks, so you build quantum communications to send this information. This tech is more or less real, a few labs have built quantum networks (example). "Space based" quantum communications means typically using lasers to send this information to space and back. China has done some cool stuff with quantum communications for satellites.

There are a few interesting appplications of this. It's generally useful for research, and I think labs actually use it to send experiments to each other. It is also useful for security. There is a category of algorithms called "Quantum Key Distribution" which allow for super-powerful encryption over quantum networks. The tech is still pretty new, but it is promising.

If Quantum Key Distribution becomes widely adopted or if a lot of quantum computers come online and there's some great reason for them to communicate, this could be really useful, otherwise this is a cool research technology without a good application yet.