Orbital velocity: $v_o$ = sqrt$\frac{GM}{r}$ = sqrt($gR^2$/r) where r = R + h

For near-surface orbit: $v_o$ = sqrt(gR) = 7.9 km/s Time period: T = 2pir/$v_o$ = 2pisqrt(r^$\frac{3}{GM}$)

Near-surface: T = 2pisqrt$\frac{R}{g}$ = 2pisqrt(6.4$x10^6$/9.8) = 5075 s ≈ 84.6 min

Important relations:

• $v_o$ decreases as orbital radius increases (outer orbits are slower)
• T increases as orbital radius increases (outer orbits take longer)
• $v_e$ = sqrt(2) * $v_o$ (at the same radius)