English: A bi-parabolic transfer from a low circular starting orbit (blue), to a higher circular orbit (red) around a central body (black). When the spacecraft arrives at point 1 it performs a prograde burn to enter a parabolic escape trajectory (green) until it reaches infinity. Then an infinitesimally small prograde burn brings the spacecraft to the second transfer parabola (orange). Finally at the vertex (point 3) a retrograde burn slows down the spacecraft to the final circular orbit.