Yeah something that small is going to be fine. But the ISS will not be. It's 440 metric tons, generating 4.4 MN of force on a cable. That's not going to spin.

Yeah something that small is going to be fine. But the ISS will not be. It's 440 metric tons, generating 4.4 MN of force on a cable. That's not going to spin. And you're sending something to Mars here. In the ideal case we'll be sending six worth of supplies at the same time per person per ship. The amount of people permitted by NASA's guidelines on long-term habitation on a ship based purely on volume range from 1 for smaller ships to 30 for something the size of Starship. Hauling everything they need is not going to be below 50 metric tonnes by any means. We can probably spin as much as we like here, near the Earth, but anything further away is going to have ropes the breaking strength of which is again measured in meganewtons and the width of which is going to be around half a meter. Making that out of steel for the kind of cable you'd need for comfortable spinning (~1 rpm, 1.6 km of cable) is not going to space any time soon. At the very least 6 months of food is required for the crew module, or some complex procedure of periodic de-spin & rendezvous with a cargo vessel. The kinds of missions NASA has been planning are 30 months in overall length if everything goes well, though 24 of that is not required to be accessible during transit. Spinning again in ĺow martian orbit is going to be quite feasible, once you jettison all of your life support and such and instead do very frequent cargo stops.