Astronomers still have long way to reach stars (brief from recent 100YSS conference)
 

Short report from the recent 100YSS conference.
Possibly nothing new but fascinating stuff nevertheless.

Astronomers still have long way to reach stars

Amazingly, AFAIK, Project Valkyrie is still the most viable option, but it is still astronomically expensive. (Pun very much intended. ;)) It has energy costs comparable to the output of entire countries at minimum, before you get things like engineering losses and energy costs to store its fuel.

(The fuel in question happens to be supercooled antihydrogen. This is not the most stable substance in the universe.)

I'm no physicist but I do find this subject fascinating.

You can see why Cameron based his ISV on Project Valkyrie and concluded that only private enterprise would be able to meet the expense of such an undertaking, as you point out.

There's pretty much nothing private enterprise could use a Valkyrie ship for, it's that expensive.

Yeah, it's the basis of the ISV's engine; the ISV just has the solar sail added as well.

Honestly, it doesn't matter about distance so much since it will be a few decades until we can visit; we should at the very least be sending probes to nearby systems so we know what to see when we can visit :) - even if they take 20-30 years to arrive or so, that's fine since then we will have the data by the time it's plausible to go there.

You'll need some serious infrastructure to get anything at all to Alpha Centauri within 40 years, unfortunately. :( (i.e. to get even 1kg there and stopped needs ~10% of the energy the entire modern world produces in a year.)

Of course, that doesn't matter since speed can be reduced as necessary until one can be launched since FTL is a long term investment, not to mention the whole list of tricks to save on delta-v.

Depending on the results of various theories, FTL might not be possible at all. :P