If I am in a spaceship and it begins a constant acceleration of 9.81 m/s^2, would I be able to stand up in the spaceship and it would feel the same as gravity? (This is assuming the fact that my feet were placed in the direction of the thrust source.) I've done some equations, and a ship with this hypothetical acceleration capacity (regardless of fuel source, and assuming it could compensate for its mass increase due to relativity)... My calculations put it at reaching Saturn in 225 days... Here is the data I am using: Distance to Saturn = 1,321,416,800 km After 24 hours of continued acceleration (+9.81 m/s every second) the velocity would be roughly 848,000 m/s By day 100 it would be 84,800,000 m/s And by the day you reached Saturn (day 225) it would be 190,800,000 m/s or roughly 426 million miles per hour -- and 63.64% of the speed of light. Are these numbers totally wrong? Someone smarter please help me. Thanks!