How many burns are involved in a Hohmann transfer between coplanar circular orbits with minimum delta-v?

How many burns are involved in a Hohmann transfer between coplanar circular orbits with minimum delta-v?

• A. Three burns
• B. One burn
• C. Two burns
• D. Four burns

Answer: (C)

The key idea is that a Hohmann transfer between coplanar circular orbits uses two velocity impulses. You create an elliptical transfer orbit that is tangent to both circular orbits. The first burn occurs at the inner orbit to inject into that transfer ellipse, changing your velocity to match the transfer path. The second burn happens at the outer orbit’s intersection with the transfer ellipse to circularize onto the final orbit, returning your velocity to the circular speed at that radius. Because the orbits are in the same plane, no plane change is needed, and the two tangential burns are enough to accomplish the transfer with minimum energy. A single burn can’t both place you on the transfer path and perfectly circularize at the destination, so two burns is the optimal, minimal-delta-v solution for this scenario.