Thank you all a lot for answers and efforts to help me, but I still have some questions left. Sorry if it's too much, though. If it's not possible for a human to withstand so much g, how do they live in the international space station? It travels with around 7 km/s. So, acceleration wouldn't be that high, yes, but it'd still be uncomfortable. And how about Apollo 10 ultimate speed record? 11.08 km/s with people inside. It's speed, not acceleration, but it was high as well. Shouldn't it be extremely uncomfortable for them? Also do I understand it right, that for tolerating g forces, a human needs to wear a special suit, which does... what? Redirects the blood flow? Or air in the lungs? Or both?