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Solar Impulse, Continuing World-Spanning Trip, Attempts To Cross The Pacific
The BBC reports that Solar Impulse has resumed its 'round-the-world attempt, having taken off today from Nagoya, Japan for what is intended to be a 120-hour voyage to Hawaii. [If pilot Andre Borschberg] succeeds, it will be the longest-duration solo flight in aviation history, as well as the furthest distance flown by a craft that is powered only by the Sun. The Pacific crossing is the eighth leg of Solar Impulse's journey around the world.
But this stage has proven to be the most difficult, and has been hit by weeks of delays." The circumnavigation attempt began earlier this year.
Please return the user interface to how it was. You are just pissing the long term userbase off.
Pulling out the read more link is like pulling the start button / menu from windows 8. It is a user interface disaster because it's not obvious w\
here you should click for the comments.
Slashdot has always been about the comments, if you minimise them by obfuscating the link to them you are left with the news stories from reddit \
a couple of days late and some obvious paid advertising plants.
Implementing aspects of the failed beta interface piecemeal with no discussion seems a bit underhanded.
If you aren't lucky you might succeed at killing slashdot which would be a shame.
I am a lawyer and this constitutes legal advice and I shall indemnify you against any losses arising from taking it.
There's a pretty big difference between a solo flight in an ulta-lightweight solar-powered plane. Note that they've had to wait for months for a clear weather window, and you're claiming that it's now possible to use commercial solar-powered planes? It's sort of like claiming that because we put a man on the moon, we're now ready to build a tourist resort there.
though naturally it wont happen until it's either mandated by law
You can't pass a law of physics through legislation. This is cool and all, but don't mistake a this for any sort of substitution for current aviation tech. It's not, and won't be anytime in the near future. We need to focus our efforts on places where it IS feasible to reduce or replace our use of fossil fuels in the relatively near term. Power plants. Cars. Stuff like that. There are many people who are investigating more sustainable aviation fuels, but for the foreseeable future, these are still going to be carbon-based.
I hate sounding like a naysayer, but you need to be a bit realistic about these sorts of things.
Irony: Agile development has too much intertia to be abandoned now.
Once again : Not, it's not possible.
Here's a comment I posted 5 years ago : http://science.slashdot.org/co...
The laws of thermodynamics haven't changed much since.
It's pretty profoundly useless as a replacement for a commercial airliner or cargo plane(basically the wingspan of a 747; but transports a single pilot at a painfully tedious 50-100km/h); but suitably automated versions of the very-long-endurance solar aircraft concept have other uses. Longer life, and greater control, than balloons; but markedly cheaper to launch, and lower ping, than anything in orbit.
As a manned aircraft it's a pure novelty; but its performance is increasingly close to 'like a small satellite; but closer to the ground and requires only a large strip of pavement for launch and recovery', which could definitely find some takers.
That particular plane is designed the way it is not because they thought it looked cool, but because the realities of solar power require it. All the methods of harvesting solar power are heavy and bulky per kilowatt compared to something like aviation fuel. That means you need to have a plane that is slow (for energy efficient flight), very large (lots of area for solar panels and big wings for slow flight), and has a small cargo capacity for its size.
Even with improvements in solar panel design, the amount of sunlight that reaches the plane is limited.
The best design for a solar plane with the capabilities of current planes might well be a regular solar farm powering a conventional fuel synthesis plant.
The design can be changed; but this design is as it is in large part because of how much surface area it needs to collect enough sunlight to sustain even its distinctly frugal operation.
Improvements are likely, with better solar panels, better batteries, or both; but you don't beat the fact that optimal insolation is 1366w/m^2; and real world values typically lower, at least on average. A liter of Jet A is 35.3 MJ, so ~9880watt/h. Even at peak insolation, a square meter of solar collection takes a little over 7 hours to amount to as much energy as a liter of jet fuel. Jet engines are, of course, hardly perfectly efficient; but you get some sense of perspective from the fact that a relatively modern design, aimed at fuel efficient operation, like the 787 still has storage for in excess of 100,000 liters of fuel, a big 747-400 more like twice that.
On the plus side, your sunlight supply doesn't weigh anything, or require any volume(though your batteries do, and barring major improvements their energy density is dreadful compared to hydrocarbons); but even given perfectly efficient solar hardware, there just isn't that much energy to work with, by the standards of hydrocarbon aircraft. Any possible design is going to reflect this through some combination of gigantic wing area per unit capacity and a flight plan that sticks relatively carefully to maximally efficient speeds.
The idea of solar powered heavier-than-air flight necessitates this manner of design.