Space Travel: Newton, Kepler, circular motion, gravitation, potential and kinetic energy

Imagine travelling from one planet to another. Why is it that we have to first travel in circles instead of taking the straight path? Before going on our trip, we must consider: the revolution velocity of our starting planet, the required spaceship velocity, and the optimum momentum for launching the spaceship (because if we miss it, we’ll travel past the target planet, without even noticing it).

Finally, we need to know the fuel economy of the trip (after all, we don’t have gas stations in space).

In this teaching unit, students study how a spaceship arrives on a circular orbit around a planet, and how it travels from one planet to another on a Hohmann transfer orbit. This unit is recommended for students age 12 to 19 years.

Authors: Dionysis Konstantinou (GR), Corina Toma (RO)