BFR servicing the ISS

[Alastor]

The BFR removes any point of having a DSG anyway.
If you have a spacecraft that has the habitable volume of the ISS, can spend 6 months on orbit, and can go anywhere in the solar system for 10% of an SLS launch, then you don't need a DSG or an ISS.

I disagree.
Having a spacecraft that has the habitable volume of the ISS is a great thing, but it does not remove the need for an ISS. The main difference between them is that an ISS stays up for dozens of years, allowing to perform very long running experiments, when the BFR does not provide this capability.

That's why I think we will always need to have an ISS. BFR will however make it much more easy to build and would be in my opinion a great way to service it, since you can bring up and down a lot of supply, crew and temporary experiments.

It might even allow us to operate with a space-based laboratory not very differently than with our Antarctic stations. You could very well have a crew of specialized astronauts tasked with maintaining the station and allowing safe operation, and have a crew of scientists that would be there for a few months to perform the experiments, if the size of crew is not an issue anymore (I may need to start working on an experiment that would be very interesting to perform in pace at some point ! ).

I don't think it would be desirable to bring tourists to such a facility however. Have a separate tourists station ? Sure ! Do we even need a separate station ? I mean, space tourists won't very often want to stay for more than a few weeks. But I don't think it's a very good idea to mix the needs of a science lab and of a touristic destination.

A DSG could be seen as big on orbit fuel depot, and then would be interesting to have to allow asynchronous launching of tankers and crew. If you think about it, if every synod, you suddenly need to launch a lot of crewed spacecraft and then several tankers each, you have a lot of launching to do all at the same time, and the rest of the time, you can't do anything on that side. If on the other hand, you bring up the tankers in advance, it's suddenly much more manageable to only launch your crews close to the Mars transfer window.