A substantial chunk of ESA's budget comes through EU. So the cost of UK's membership in ESA might increase, as they won't be participating through EU anymore.

That's the kind of thing that is hard to justify to Brexiteer voters though... "Now that we're rid of the EU, we have a unique opportunity to pay more tax money to other intergovernmental organisations!"

Here you have ESA funding by source: http://www.esa.int/spaceinimages/Images/2016/01/ESA_budget_2...

EU funding doesn't go to the main funding budget of ESA but to other activities like the Galileo satellite system.

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.

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

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.

I'm sure they will continue, but as an EU member state working in the EU is much easier. Perhaps the skill levels will overcome any friction from visas and bureaucracy.

ESA is an intergovernmental organization, visas and any country laws don't affect them. Also it doesn't belong to EU, even Canada is part of ESA.