On its second flight in the most powerful rocket ever built. How many flights did it take SLS to get to where it is now - including all the space shuttle launches upon which it is based?

SLS is the project that is running over budget and behind schedule here. Starship won't be ready in time for the scheduled 2025 trip to the moon, but nothing else will be ready either - the moon landing schedule was always overly ambitious. Starship is doing pretty well along its own development timescale.

However Starship is still miles and miles away from being ready for Artemis. They need to get into space. They need to do cryogenic fuel transfers in orbit (never been done). They need to turn Starship into a human rated moon lander (SpaceX have no experience here). NASA are supposed to be working with them to provide their experience, particularly with human life support, however AFAIK they haven't even started collaborating in earnest yet.

[–] pennomi 1 points 11 months ago

It’s hardly fair to include all shuttle launches in SLS development. It’s virtually an entire new system, minus the engines.