Have you ever wondered how we do space travel?
There’s a special little trick that space agencies use that allows them to travel hundreds of millions of miles without needing any fuel at all… they use Newtonian mechanics.
An object in motion stays in motion. If you’re in orbit around Earth, to travel to Mars without carrying up tons and tons of fuel, all you need to do is wait until you’re at the right part of your orbit, put the pedal to the metal for a few minutes then turn it off.
What happens when you accelerate forward when you’re already in orbit? You change the shape of the orbit! Using this trick all we need to do to travel the solar system is simply orbit to our locations. This is called a Hohmann transfer orbit.
Using orbits to travel space has a downside. What you gain in efficiency of fuel and cost you lose in opportunity.
All the bodies of the solar system orbit around the Sun at different speeds and so this creates a situation where we need to wait for “launch windows” to open up, times where we can launch into a Hohmann transfer orbit and expect to arrive at a certain place of orbit the same time as our destination gets there.