Can't we just lob a few modified Raspberry Pi's (you know, the one designed by some clever and charitable Brits for free) into space, along with some (good) atomic clocks somehow, and use those ?
That could do the trick! ;-)
One should remember which country invented the ARM chip the Pi uses, which also now drives most of the worlds phones and tablets. It wasn't the Americans, the French or the Germans, or even the Japanese (even though they own it now, which says it all I guess) was it?
No it was a tiny computer firm in Cambridge called Acorn, and the brainchild of one brilliant person - Sophie Wilson. I'm not for brexit at all, but we've collectively made our decision and will have to make the best of it.
We've still got some brilliant people here, and we Brits tend to pull together when the chips (pun intended) are down. We'll be OK. Or at least I hope we will.
I was watching a video about how the Americans refused to share the technology of nuclear bombs after the war even though we'd helped them with it. So then we just made our own without their help, one way and another with a team led by Dr William Penney. They weren't pleased but I think it taught them a bit of a lesson.