Orbital position
= Orbital position
{title2=$\mathbf r(t)$}
A body's <position> along its <orbit>, specified relative to a stated origin and time. Knowing only the shape and size of an <orbit> does not specify where the body lies on it: an initial orbital phase or timing condition is also needed. A rendezvous requires matching <orbital positions> at the same time as well as matching <velocities>.