Fusion power has been 30 years for at least the last 30 years, and probably since the 1960s.

This article has a bit more detail on some of the subjects this video covered, and also the 30 year timeframe:

http://blogs.discovermagazine.com/crux/2016/03/23/nuclear-fusion-reactor-research/#.WCWhnuF97fA

Who said it would be free?

It would be unlimited and therefore approaching a zero-cost, but it won't be free. As the video explains, fusion plants will cost a ridiculous amount of money to build.

But we either do it, or forget about a hi-tech (i.e. energy intensive) future.

For what it's worth, as an Irish whiskey drinker (in both senses of the phrase) I can tell you that the nicest whiskeys I've tasted from outside Ireland and Scotland are Japanese, including a Santori whose name eludes me.

In case you're interested, next comes Indian (a lovely tipple called Amrut Fusion), followed by a few nice American samples... I'm not a big fan of bourbon, hence the placing.

As for the spelling thing, yes, usually Whisky is Scotch and Whiskey is Irish, but that's not 100% true, and if that's your worst spelling mistake after a few then you're doing well.

*promote fast talking, fast feet.

Promote the fusion.

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A matter of scale, distance & speed. (assuming we are talking about electrically driven engines like ion drives or the proposed EM engine.)

If nothing else, the sun gets weaker the further away you get. Out at the edges of the solar system it's almost negligible.

Given that mass directly effects net thrust & fuel range, smaller craft working in the inner solar system may well be better off sticking with solar over a bulky reactor.

Larger and or longer ranged ships should start to favour fusion reactors and such.

Unless of course they manage to miniaturise the fusion apparatus, or perhaps harness quantum effects like matter/anti-matter. etc. etc.

Surface area to volume ratio also starts to shaft solar power the bigger the ship gets too. The panels would have to get exponentially bigger along with the ship/engines.

I couldn't tell you exactly where, but there will be natural tipping points between the practicality of one over the other.

Edit: The calculation would mostly be the ratio of energy produced to mass of the generating apparatus. The point where a fusion reactor (inc it's fuel) can produce more required power per unit of mass than solar cells (and associated gubbins), is the point where it becomes more efficient for most spacecraft.

Though solar still has a clear advantage where indefinite operational duration is a factor. (fusion requires fuel, albeit in small quantities)

Because the Sun doesn't have a convenient plug socket

There are some pesky logistical problems in harnessing even a fraction of the suns output.

It's not that it can't be done but.......we could instead just make our own fun sized suns like these people are trying to do.

Nothing else could really touch the output of a fusion reactor if (when) they finally nail it.

Not that solar cells wouldn't still have their niches, or a stopgap role in the mean time.

Can you build a solar powered long-distance spacecraft? Or would fusion be better?

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Why are we building fusion reactors when there is a giant, natural one already there that gives us all the power we could ever need?

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According to digg,

Notably and surprisingly absent: anyone from the United States.

I'm confused. They imply a 3 day trip to mars is possible, but is that at the maximum speed photonic propulsion can deliver, or do they include the acceleration and deceleration times? As I understood it, photonic propulsion can deliver extreme speeds, but only at a minimal acceleration. That means that maximum speed is much faster, but accelerating to that speed takes immensely longer, and the same goes for deceleration. Maybe they've invented a new method I've not heard of with much higher acceleration, but that's not really mentioned in the video.
They actually seem to imply they plan to use the same tech as cyclotrons, which means essentially a huge rail gun (and that's not photonic propulsion BTW, it's magnetic). Again, the amount of propulsion is miniscule, but the top speed is high with that method. Yes, you can expel matter at near speed of light, but only in tiny amounts and using huge amounts of energy.
Yes, it may take 10 minutes to achieve 30% the speed of light....with single molecules or atoms.
There are MANY reasons why we can't do this at macro sizes. Just look at the size of a cyclotron needed to accelerate an atom to those relativistic speeds. Now think about sizing that up to accelerate enough matter to move a spaceship instead of a single atom and it's likely near the size of the entire planet. We won't be building a cyclotron that size ever, nor will we likely ever shrink the accelerators to a size where they can fit inside a spaceship to shoot trillions of atoms out like a light speed gun. They are just too big and use too much power. Maybe once fusion is perfected and miniaturization also perfected it could work for interstellar travel, but never for local space travel, the acceleration levels are just too small.
Also, it seems solar sails give the same or better acceleration to the same top speeds without the impossible technology....but they don't work too well for stopping except at other stars.

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I wonder how this affects fusion reactors already being build and tested. Is it back to the drawing board then?