1. The problem statement, all variables and given/known data The International Space Station (ISS) circles the earth at an altitude of 347 km. What is the period of the orbit of the ISS expressed in minutes? G=6.67x10^-11 N * m^2 /kg^2 M(Earth)=5.98*10^24 kg 2. Relevant equations T^2/R^3 = (4Pi^2)/(GM) So: T^2= Sqrt(((4Pi^2)/(GM))*(r^3)) 3. The attempt at a solution Alright, so I've been plugging in these numbers for awhile, and I keep getting the wrong answer: 1.1 seconds. The right answer is 91.3 min. T is in seconds when initially calculated, right? I'm still doing something wrong, but I'm hoping to just double check on that.