> The distinction is kind of meaningless

Only if it helps you to call this "science", I would say.

> advancing our engineering capabilities in space is advancing the science

In this case, we are advancing our engineering capabilities to make humans survive in space, which is arguably completely useless.

Not only that, but we keep focusing on the easier and fun part for engineers. A real problem for surviving in space is life support, see e.g. this: https://mceglowski.substack.com/p/a-primer-on-long-duration-....

But it is a lot less fun than sending humans around the moon in a ship that doesn't need them at all, isn't it?