Space vehicles traveling through Earth's radiation belts can intercept a significant number of electrons. The resulting charge buildup can damage electronic components and disrupt operations. Suppose a spherical metallic satellite 0.9 m in diameter accumulates 2.2 µC of charge in one orbital revolution. (a) Find the resulting surface charge density. C/m2 (b) Calculate the magnitude of the electric field just outside the surface of the satellite, due to the surface charge. N/C 2. Relevant equations a. Looking at the units I need the answer in, I assumed that the surface charge density is charge/area or C/m^2. for this problem that would be Q /(pie x r^2) or 2.2e^-6C / (pie x .45^2) So I solved and got 2.2e-6/.6361725124 = 3.458e-6 This is not the right answer - I can't find part a which should be easy - a little help please.