Here's a short article on the issue from Feb 2017: http://spacenews.com/u-k-could-be-locked-out-of-some-aspects-of-galileo-because-of-brexit/ http://spacenews.c

Here's a short article on the issue from Feb 2017: http://spacenews.com/u-k-could-be-locked-out-of-some-aspects-of-galileo-because-of-brexit/ http://spacenews.com/u-k-could-be-locked-out-of-some-aspects... and a better one from last summer: http://spacenews.com/britains-quitting-the-eu-but-will-it-be-forced-out-of-eu-space-programs/ http://spacenews.com/britains-quitting-the-eu-but-will-it-be... TLDR: ESA is separate from the EU, but there are significant projects like Galileo which are EU projects - and the EU wants to be built in the EU. Surrey Satellite Technology is a UK company -- despite being majority owned by Airbus -- and currently builds the navigation payload for Galileo.