[pavlov]

Here's a source specifically for the EU portion of the ESA budget:

http://www.esa.int/About_Us/Welcome_to_ESA/ESA_and_the_EU

"Some 20 per cent of the funds managed by ESA now originate from the EU budget."

I'm not disagreeing with you, but it seems unlikely that UK just won't participate in that 20% of ESA activities anymore. So they'll have to renegotiate the membership fee to account for that.

[throwaway049]

It might not need a renegotiation as such, just a direct payment of the same amount as previously went via the EU account.

[pavlov]

Britain can't unilaterally decide to do that. So, a renegotiation is needed.

That's a big problem with Brexit. Some highly visible supporters promoted the idea that Britain will simply be able to dictate new and more favourable terms for everything that happens through the EU framework currently.

It's essentially the same as what Trump is saying -- "I'll deal with China. I know how to make deals. I'll make a great deal" -- With no specifics on what the deal would be and why the other side would accept it.