In the previous section, we calculated the values of Av for (a) departing from the synchronous motion of the Earth about the Sun to the Hohmann transfer orbit, and (b) from the Hohmann transfer orbit to a motion synchronous with the motion of Mars about the Sun. What we'd really like to know is how much Av we'll need to get from a spacecraft rotating about the Earth in low Earth orbit (LEO) to a spacecraft rotating about Mars in low Mars orbit (LMO). First, we'll need the low-orbit velocities. Again using:
v 2 = £ a for a circular orbit, we find for LEO and LMO:
These are the velocities of the spacecraft relative to the planets when it is in low orbit about a planet.
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