# Are destination coordinates sufficient to travel to a far place?

Imagine we want to go to Alpha Centauri,

Let's assume we are at position {100, 100, 100} and the star is at position {1000, 1000, 1000}.

Is this way of positioning (cartesian coordinates) sufficient for such journey ?

What I mean by that is, in real life generally things are more complex than a simple vector, there are certain roads you must take, things you'd want to avoid and so on. And here you have GPS which while does the positioning it also has a database of places/routes etc ...

Like when going to the moon, while it's clear on where to go, it is not a matter of going on a straight line, you have to avoid stuff like space debris around earth and so on (simplified example).

Question:

What would one need when travelling far in space, beside destination coordinates ?

• I'd recommend you narrow this down to sane distances to keep this in the fact and not fiction category, and therefore on-topic. While intergalactic navigation is always done by Guild Navigators and plenty of spice gas, for this SE site better stick to humans and say the closest dozen stars. (better image) – uhoh Aug 22 '17 at 7:48
• changed it, hope that's better now ! – aybe Aug 22 '17 at 14:38
• You'd obviously have to avoid hitting other planets (and Proxima/Beta Centauri) on your way out of our system and the way into theirs, but, after that, the space between us and Alpha Centauri is fairly empty. Your main issue would be proper motion, since Alpha Centauri is itself moving (so is our own Sun for that matter). – user7073 Aug 22 '17 at 14:48
• @barrycarter that's some of the unknown I was asking about, what are things to consider, the approach to take and so on, i.e. a journey has to be planned on the geographic aspect. – aybe Aug 22 '17 at 15:07
• It's 99% a straight line journey, but the straight line has to end where Alpha Centauri will be when you get there, which depends on your speed. And, because there is uncertainty in proper motion, you will have to adjust occasionally as you get better data. – user7073 Aug 22 '17 at 16:21