Ion Drives and Rockets


Most spacecrafts use chemical rocket engines to propel themselves around in space. Spacecrafts use chemical rockets because they produce a high impulse, which is the change in momentum produced in a given amount of time. Therefore, these engines don’t have to run for long, since they can generate the needed force to move quite quickly. The energy produced from the chemical combustion is great, but the time the reaction goes on is relatively short.

Now consider the ion engine, which is a completely different beast. These engines operate by electrically shooting ions (atoms which lack an electron) out of the back of the spacecraft. Each ion moves at incredible speeds, but since they have such a low mass, the “push” they give to the spacecraft is very tiny.

However, the crucial difference between the ion and the chemical rocket engine is that the ion engine runs for much longer. The trick is that it applies a small impulse for a long period of time, achieving the same net force (change in momentum) in the end. Instead of producing a huge change in a small period of time, the ion engine exerts a small change over a longer period of time, allowing the spacecraft to navigate during long voyages. The chemical rocket engine is made for the short term, while the ion engine is for the long term.

This concept can be quite easily translated to honing our craft. For any discipline, a long-term mindset is key. As such, we need to use the idea of applying a small impulse for a long period of time, like the ion engine does. What this means is that, every day, you take one small step forward towards your goal. It doesn’t have to be anything world-shattering. In fact, it’s better if it is not. A small step is best, since it’s sustainable.

The real change between the person you are now and the person you want to become is the sum of all those small steps, not any one step in particular.

Related Posts

The Grit to Push Through

Behind the Equations

Quantities in Context

Black Boxes

The Priority of Education

A Splash of Colour

Outside the Curriculum

Through the Minefield

Visuals in Mathematics

The Necessary Details