There’s no north or anything, are there coordinates or you just point at a planet and go for it?
In: Physics
No, you can’t just point at a planet and “go for it”. For two main reasons.
The first is that if you pointed at where you needed to be, you would never get there. Space travel is unintuitive. Nothing goes in a straight line because there is always some planet or moon (and the Sun) bending the path. For example, instead of pointing straight up, you need to point sideways and accelerate in oder to get further from the surface. If you did point straight up, you would get further away, temporarily; until your fuel ran out. Then after coasting to a stop you would fall back to the surface.
The second reason is that planning a route takes a lot of work. Most of the weight of a spacecraft is fuel. It takes a tremendous amount of fuel to get something into space. Missions are very carefully planned to uses the least possible amount of fuel. It is very common for deep space missions to fly close to a planet(s) in order to steel a little bit of velocity from it. That’s called a “gravity assist”. Sometimes making many passes – each time increasing velocity so that it can reach a higher orbit.
A combination of Inertial Navigation, Radio Navigation and Astro Navigation are used to keep track of position.
Inertial Navigation is keeping track of your speed and direction using very sensitive devices. It is accurate in the short term but it needs to be updated using other methods.
Astro Navigation is using distant stars to figure out your orientation. This is very accurate in determining where you are pointing but less so in pinning down exactly where you are. Planets, moons or other bodies can also be used.
Radio navigation can determine very accurately how far you are away from Earth. Basically by timing the radio signals.
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