Navigating To Another Star System

[happyhacker]

TL;DR

Navigating to another star system.

I assume that as the light years to another Star reduce the position of the Star will change relative to other references in the navigation calculations. So what adjustments would be necessary to a Starship's course as it gobbles up the distance to maintain pointing it's nose at the destination?

PS Google and YouTube seem to interpret 'Navigating to another Star' as "Navigating by the Stars" but then I'm not an expert Googler!

 

[Drakkith]

You don't navigate to a star by pointing your nose at it and thrusting forward. This is because the star is almost certainly moving relative to you, and if you point your nose at its current position, it will move out of the way by the time you get there!

What you do is you compute the position of the star over time and then try to match up your own course to intercept it. This is a very, VERY complicated process. Even spacecraft moving between the planets in our own solar system require lots of computational work to get accurate course plots.

Ideally, you would compute the course, thrust to get your ship on that course, and then slow down once you reach your destination. However you're almost certainly going to need to do a few course corrections along the way since we don't live in a perfect world.

I assume that as the light years to another Star reduce the position of the Star will change relative to other references in the navigation calculations.

Not only that, but the references themselves will change as well. All the stars are moving, so your own reference system is dynamic, not static, which greatly complicated matters, as you have to compute the future positions of all of those stars as well as the destination star.

 

[anorlunda]

Distant pulsars are the reliable beacons upon which you can do accurate interstellar navigation.

 

[DaveC426913]

What you do is you compute the position of the star over time and then try to match up your own course to intercept it. This is a very, VERY complicated process. Even spacecraft moving between the planets in our own solar system require lots of computational work to get accurate course plots.

I suspect interplanetary navigation is much more complex than interstellar navigation.

The gravitational influences in interstellar space are orders of magnitude smaller. Possibly enough that you can virtually discount them and assume that stars are moving in simple linear motion wrt each other and the sun, and that your course will also be similarly straight.

That doesn't mean you don't have to account for the motion of the target star so that it's there when you arrive, but I think it means it can be treated as near linear motion.

 

[Drakkith]

The gravitational influences in interstellar space are orders of magnitude smaller. Possibly enough that you can virtually discount them and assume that stars are moving in simple linear motion wrt each other and the sun, and that your course will also be similarly straight.

Probably. Taking UY Scuti as an example, if we were to spend about 10,000 years in transit, the star would have moved by less than 1 lightyear, or less than 0.01% of the total distance traveled.

 

[DaveC426913]

Probably. Taking UY Scuti as an example, if we were to spend about 10,000 years in transit, the star would have moved by less than 1 lightyear, or less than 0.01% of the total distance traveled.

Perhaps, Though the magnitude of the change is far less troublesome than the complexity of the change.
The movement of both UY Scuti and our spaceship is effectively linear. No orbital components to worry about.

 

[sophiecentaur]

However you're almost certainly going to need to do a few course corrections along the way since we don't live in a perfect world.

It strikes me that the complexity would be all at the far end where you would want to get into a suitable orbit round the star in the presence of, perhaps a couple of large planets to help you into place. Your greatⁿ grandchildren could be very impressed when it all works - or maybe not??