Minimum Viable Habitat

What is the shortest path to simulating artificial gravity?

The notion of rotating a space station to produce artificial gravity is older than the space age itself. But after 65 years of human spaceflight, it has never been implemented.

The reason for doing this, aside from for comfort, is that microgravity has serious health effects on humans; we lose muscle and bone mass, the heart weakens, flows of fluid to the head can impact eyesight and even cause neurological issues. Some of these effects can be mitigated by a very intense workout regimen, but it is ultimately a losing battle. For most people a few months of exposure requires extensive recovery when back on Earth, and some effects can persist long after returning. If we want to make living and working in space widespread and routine, and allow long term stays, we cannot subject people to these conditions.

There are barriers to doing this. If a spacecraft spins too fast, or if the radius of rotation is so small that there is a significant difference in the force felt between the head and the feet, people inside can become nauseous.