1. The problem statement, all variables and given/known data Vladimir Titov and Musa Maranov spent just under 366 days in the Mir Space Station during 1987 and 1988. Work out how many seconds they had time travelled into the future of Earth time. 2. Relevant equations The orbit was circular at a height above the ground of 390km, the radius and the mass of the Earth are 6378km and 6x10^24kg. G=6.7 x 10^-11 3. The attempt at a solution I found the velocity using the formula v=squareroot(GM/r)=7706.96m/s The time elapsed on Earth is 366days=31622400 seconds So the time elapsed for the travellers is Tt=Tearth/gamma =31622399.99 Is this correct? The time difference seems extremely small :S. Do I need to take anything else into account?