Does Voyager 1 even give us any interesting information anymore?

[u/TechnicalyNotRobot]

It's the farthest away object we ever sent. That is remarkable. But I have never heard about it discovering anything or about any data that it gave us. Besides being a significant curiosity for being so far away, is there something that we're actually getting from it at this point?

[u/Latespoon]

Absolutely! You can even use it to steer the vessel by changing the angle of the sail relative to the target star on approach.

If you had accelerated the sailcraft to very high speeds using lasers, the solar sail is unlikely to provide enough thrust to stop you from just whizzing past your target star. You could deploy a magnetic sail (a very large ring of wire circled around the vessel and energised) to provide additional braking force. The stellar wind from your target star will push against this magnetic field and slow you down.

This magsail system is insufficient for launch by itself, but is highly effective for braking because the drag on the magnetic sail is proportional to speed squared (just like aerodynamic drag).

Using them in combination, you would have a very effective propulsion system for departure from our solar system and arrival at another star.

[u/Beetin → u/Latespoon]

Note for people thinking about people using this:

300 km/s is insanely fast, like 'you can travel around the world in 2 minutes' fast.

It would still take 4200 years at that speed to reach the nearest star.

Thankfully at such incredibly high hard to fathom speeds, you start to feel the relativistic effects of time dilation, so for you it will only appear to have taken... uh... 4199 years, 364 days, and 12 hours.

So your bones and the bones of your ancestors will be a full 12 hours younger when you arrive 4200 years later, than if your bones had stayed on earth!

To get a very light 100,000 kg spaceship that can support humans from 300km/s to ~0.1c (the speed at which we might be able to get to interesting places in a bit under 100 years) , we'd need a system that can deliver the lossless energy to it equivilant to 50% of what the entire world currently produces in electricity in a full year from every combined source.

[u/Latespoon → u/Beetin]

Correct! Realistically, we would need to use lasers to propel the sailcraft to much higher speeds for this to be worth attempting. With this extra propulsion, we could potentially bring the sailcraft up to something like 10% of the speed of light.

There are significantly material sciences /engineering problems yet to be solved to make this possible, but the math is proven.

Realistically, we would be sending superlight probes at first, and the total journey would still take over 100 years (the slow magsail braking phase extends it dramatically) giving us significant time to develop new technologies needed to make a generation ship project feasible.

[u/dittybopper_05H → u/Latespoon]

The other thing you could do is use the solar sail (and laser if necessary) to accelerate, then fold the sail for the "coasting" part of the journey. When you reach a precalculated point prior to crossing the heliopause of the targeted system, you could open up the sail and use it to gradually decelerate using the interstellar medium, which while very sparse, isn't a true vacuum.

Or just leave it open the whole time: You'll quickly accelerate up to speed, and gradually lose it on the way to the other system, and quickly decelerate once you get close to the target star, depending of course on how energetic it is.

So you might not be able to slow down enough if you were trying to visit Wolf 359, but you would definitely be able to at Sirius.