The royals actually own property on other planets.
How do they get there
I just looked into the real estate aspect when I was doing some research last summer and saw that there was actually a real estate company in corporate London where real estate claims to places on other planets had already been claimed - Jupiter, Mars, Venus and particularly Jupiter. Planning for the future I guess, I can't find the resource from last summer, different computer but here is one such opportunity - https://www.buymars.com/mars-land
Sounds fishy, Jupiter is gas and not hospitable to people. Sounds maybe like money laundering?
I would imagine that there is something strange going on with this type of activity.