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Japanese Deploy Solar Sail
Chuck1318 writes "The Japanese ISAS (Institute of Space and Astronautical Science) announced the launch and deployment of the first ever large-scale solar sail. In the news release they state "Because it carries no fuel and keeps accelerating over almost unlimited distances, it is the only technology now in existence that can one day take us to the stars.""
"...it is the only technology now in existence that can one day take us to the stars." Well, unless the Japanese can automate retraction of the sails, it wont reach any stars. While it's powered by solar wind, it will slow down and reverse as it gets farther from the original star and closer to the destination star.
You are confusing me with someone who cares.
"Because it carries no fuel and keeps accelerating over almost unlimited distances, it is the only technology now in existence that can one day take us to the stars."
This may be true, but it'll take another technology to take you there safely: brakes.
This whole "keeps accelerating" schtick concerns me from a self-preservation point of view...
I'm no scientist, but wouldn't the thrust follow the same inverse-square law as radiant light?
To make best use of a solar sail, it would probably make sense to use a conventional rocket to establish a highly eccentric (parabolic) orbit around the sun and then pop the sail open after perihelion where the sail would contribute the most energy to the orbit.
I think aiming the spacecraft (on the outbound journey) would be the hardest part.
Because Orion needs to carry its fuel, its period of acceleration is necessarily limited. If you count Orion as a star-faring technology, then you need to count chemical rockets, too... Just ask Pioneer 10.
The Mongrel Dogs Who Teach
Ironically, this technology can take us to 'the stars' but not toward our own.
.5 C, it'd take thousands to millions of years to get anywhere. But, at relativistic speeds, it'd still take thousands of years, but to the crew on board, it'd be like mere hundreds or even tens of years.
And, why not?
Sailing ships have sailed "upwind" for many centuries.
In outer space, you are either in orbit, or falling directly towards the nearest large body. A solar sail can be used to slow down or accellerate lateral speed simply by rotating it 45 degrees.
A simple google search turned up this in case you are curious.
Although they are right, in that solar sails do accelerate the entire trip and carry no fuel, I don't think that sails are "the way to go" unless we're talking about a ten thousand year multi-generational ship.
I consider the Bussard RamJet the "only way to fly". It carries no fuel, but is powered by carving a planet-sized swath out of the ambient hydrogen atoms out of interstellar space and fusing them.
With interstellar distances, the real issue is: how quickly can you get to relativistic speeds? Because, at
You need power to get you there in less than hundreds of years - thus the RamJet.
I have no problem with your religion until you decide it's reason to deprive others of the truth.
We need to remember to always ask the question do we really need to go to another planet when we can't seem to get along with each other here. We don't even use our natural resources with the level of accountability that we should given that for right now this is it for us. We have yet to even mine an asteroid. We really need to work out just a few issues before we start littering the solar system with McDonalds wrappers.
I forget what the theory is called but if we deploy the probes now. later, we will develop faster probes. The faster probes will over take the older slower ones. Another question is that will we be around to hear from the probe and will anyone back here remember to listen for it.
WARNING: Viewing This Sig May Cause Blindness.
These solar sails are pretty useless.
That's because they weren't designed to be useful--they were designed to gather data for the purpose of eventually building useful ones. This particular article is light on details, but the report I saw on the news here had someone from JAXA explicitly saying they are in a preliminary data-collection stage.
What the hell is wrong with you? You hear of a well-thought-out idea developed, examined, and approved by physicists, and without looking into it, you dismiss it with your first couple of off-the-top-of-your-head thoughts.
OF COURSE it's not shining laser light into the sails from the ship itself, like a sailboat with a fan on it, you unbelievable moron. And as for getting "worse and worse with aim", you DO NOT TRY AND POINT THE LASER AT THE FAST-MOVING AND LIGHT-YEARS-DISTANT SPACESHIP, AND DO COURSE CORRECTIONS BY MOVING THE LASER, you just keep the laser pointed at the destination, and do course correction at the ship.
The problem here is not so much that you completely misunderstood the whole concept, it's that you so vastly overestimate your intelligence and knowledge that you didn't recognize your stunning incapacity to evaluate this suggestion.
So let's review:
1- you're not as bright as you think
2- other people are brighter than you think
3- other people have often evaluated things a lot more thoroughly than you are capable of doing in 30 seconds
4- if you don't understand something, it's more likely your own defect than a problem with the expressed idea
5- sit down and shut the fuck up, you arrogant ignoramus
Now that that's out of the way, there certainly are practical issues with this method of space travel. It's just that they have absolutely nothing to do with what you thought they were.
Some of which can reach the speed of light? Ok, I'll resist the urge to ask what you're smoking and instead give you the benefit of the doubt and ask: Huh? Could you explain that, please?