Japan Successfully Deploys First Solar Sail In Space
An anonymous reader writes "This morning the Japanese space agency, JAXA, successfully unfurled a solar sail in space for the first time. Solar sails offer the best hope for deep space exploration because they eliminate the need to carry fuel. The Japanese spacecraft IKAROS created centripetal force by spinning, allowing it to launch the 0.0003-inch-thick sail. While deployment is a challenge in a zero-gravity environment, spacecraft — unlike airplanes — don't have to contend with drag, so with each photon that hits the sail helps the spacecraft gather speed."
I thought those crazy japanese were angels, but much to my surprise, they climbed aboard their starship and headed for the skies.
Joy! Beautiful spark of the gods!
Jetpacks? No. Flying cars? No. Sentient robots? No.
Solar sailing? Oh yes! I love this, it's one of the signals that we're living in the future, if you grew up on Clarke, Asimov et al. Required reading: Clarke's "A Wind From The Sun", Stross's "Accelerando".
Please consider this account deleted, I just can't be bothered with the spam anymore.
Here are we, the US, once the leaders of space exploration, have spent billions of dollars to go back and relive some glory (Moon shot) and canceled that, we have canceled the Shuttle program with no other vehicle to replace it, and in the process put a halt to much basic research.
We're kind of like that pathetic ex High School jock that's trying to relive his glory days.
RIP America
July 4, 1776 - September 11, 2001
Centripetal or Centrifugal?
Spinning creates what is commonly called Centrifugal force, and the tethers of the sails constitute what is generally referred to as the Centripetal force.
About here is where some physicist jumps up and tells me everything I learned in the past is wrong and I should shut up and sit down.....
Sig Battery depleted. Reverting to safe mode.
Commence whining about the death of the US Space program, the US falling behind other nations, and how it's all the (Pick one: Obama, Bush, Clinton, Bush Sr.) administration's fault in 3.....2......1....blastoff.
Don't get me wrong, it's all basically true; it's just tiresome whining to listen to.
Seriously. If you're going to make a real-life attempt at a Bond plot, at least change the name of your giant solar sail.
How are sites slashdotted when nobody reads TFAs?
Also, how well does the membrane hold up to minuscule debris? Is it durable for extended voyages (outer solar system, extra solar)?
What is the maximum velocity it could reach with the available solar wind prior to it ending at the heliosheath?
If they could combine it with something to scoop up stellar gas, along with something to process the gas into energy for steering and braking, you would have something useful.
And please no Uranus comments for my subject line...
Oh for fuck's sake why do we keep linking to Inhabitat for news on space missions? The Ikaros project is, indeed, a newsworthy and exciting piece of nerd information. However, linking to a stupid environmental blog that holds informational gems like:
.0003-inch-thick sail," borders on painfully irrelevant.
/endnerdrage
"Solar sails offer the best hope for deep space exploration because they eliminate the need to carry fuel." (Hint: No, they don't. They don't do that at all. You need maneuvering thrusters to align your spacecraft before deployment. You need a power source to provide electricity to power your control motors when you get too far away from the sun. Saying solar sails eliminate the need to carry fuel is like saying that a spoiler eliminates the need for a gas tank on a car because it improves gas mileage. That is a completely asinine statement.)
And:
"spacecraft — unlike airplanes — don’t have to contend with drag," (Also untrue. Depending on what orbit/space environment you are in, you may still have to contend with the drag of Earth's atmosphere. If you are deploying in LEO, this could induce a significant moment on your spacecraft. Also, thank you for pointing out the difference between aircraft and spacecraft...that was really weighing on my mind while reading about a spacecraft mission that is proof-of-concepting a new technology).
And:
"Of course, aliens aren’t the only reason to want to travel through space without carrying rocket fuel. NASA is also working with solar sails to develop ultra-efficient spacecrafts. " (Aliens and ultra-efficient spacecrafts eh? That's your high-quality independent journalism right there? Give me a break this kind of stupid babbling about a very important mission does nothing but patronize the spacecraft industry and the folks who worked on this particular bird).
Let me give you a hint Inhabitat readers, if you want to track the progress of an impressive space mission, try going to a news site that actually is focused on space. Maybe you should check out: Centauri Dreams or one of JAXA's own website's regarding the hardwork and impressive design that went into designing this mission. Perhaps you should read and link to some articles that actually contain interesting, relevant, tech-centric discussions of the mission rather than your latest, retarded, three paragraph, juvenile blog whose most interesting mission detail: "....allowing it to launch the
Motorcycles, Robots, Space Gossip and More!
I mean they most certainly didn't recently deploy two rovers to Mars that WILDLY exceeded expectations. They didn't then also deploy another, fixed, lander which while not as wildly successful exceeded it's planned mission significantly. Nope, none of that happened...
Oh wait, yes it did.
Please, while the US space program is not without troubles, it isn't as though it is at a standstill. NASA continues to do some amazing work, and much of it like the landers are pure science, to further our knowledge.
Stop with the US hate that is so popular on Slashdot. The US is not perfect, no nations is, indeed no human endeavor is. There's plenty to criticize and that includes in the space program. However trying to pretend as though they accomplish nothing of note is silly. Two successful recent Mars missions shows that. No, they weren't manned, neither is this Japanese craft. Putting people in space is dangerous and often not worth the expense. We can learn a lot with remote operated equipment.
I want to hear stories like this. I want to know if Solar Sails are viable. Back in highschool I wondered about a space ship propulsion device. My theory was to make particle accelerators to get the maximum propulsion out of hydrogen atoms and fire them out the back of the craft. The problem was you could run out of hydrogen. Its not something serious, but just trying to figure out something better than rockets. The solar sail sounds like it is plausible, and I'll be excited to hear this story develop. The last thing I was excited about was the Mars Rovers. How cool were those.
God spoke to me.
How does it stop? If it accelerates tangentially to the Earth's orbit, which is still the most efficient way to get to another planet, then it can decelerate by tilting the sail the other way. In each case, the acceleration vector will have a component outwards from the Sun; the ways to cancel that include furling the sail and waiting for the Sun's gravity to do the job, using a nearby planet's gravity, aerobraking in a nearby planet's atmosphere, or lithobraking. If none of the above work, then perhaps you can't stop. A bizarre scheme that has been suggested would be to bring a second, smaller sail along and use it to collect light reflected from the main sail towards the Sun (you cut the main sail loose and let it drift ahead of you), thus providing reverse thrust until the main sail is too far away. Hard to be sure how well this would work.
Debris hitting the sail? A few pinholes will make no appreciable difference to its performance. A real sail would have to be made with some sort of "ripstop" reinforcement.
Max speed? You have a misconception here: solar sails don't use the solar wind (much), but the pressure of the Sun's light. Since e=mc2, momentum equals e/c. I don't have the formula handy, but the important factors are the thickness of the membrane (thinner is better) and how close to the Sun you start (closer is better, provided the membrane doesn't melt). In theory, solar escape speed is attainable, if you're only pulling a small payload. Significant fractions of the speed of light are not attainable.
Scooping up the gas would need one **** of a scoop!
NASA had a proposed "Interstellar Probe" mission that was to use a 200 meter diameter solar sail to travel 200 AU in 15 years (the heliosheath, or edge of the solar system, is about 100 AU from the Sun). It was thought they could keep contact until 400 AUs distance. Link (go to the Interstellar Probe Report link there):
http://interstellar.jpl.nasa.gov/
This mission, as well as a proposed follow up mission (I think called Interstellar Probe 2) that would have had a bigger sail, gone twice as fast, and reached around 1000 AU, were both shelved quite a while ago. (There was a single NASA page on that second mission a long time ago, but I cannot find it now.)
You could use probes like these to sort of act as galactic weather probes, testing the interstellar space that our solar system would encounter in coming decades/centuries and seeing how that "interstellar weather" affects the Sun the the Earth's environment as we pass through it.
A theoretical improvement on a solar sail would be a "light sail"--you could set up satellites with powerful laser systems orbiting the Sun and use that focused and powerful light to push sails much faster. Some folks have hypothesized reaching 10% to 30% the speed of light using techniques like this if the lasers were powerful enough and coordinated enough. Assuming success, you could possibly send an unmanned probe to Alpha Centauri in a matter of decades. In this instance, you could theoretically use a solar sail to use the solar wind/light of the Alpha Centauri system to slow down once you started nearing it (although that could potentially add more travel time).
Things like these could be a relatively fast, cheap, and safe (as compared to nuclear) way to explore our external solar system (Kuiper Belt) and nearby interstellar space (Oort Cloud), and get a good handle on how our surrounding interstellar space affects our solar system. Very interesting stuff. I hope more of it happens!
Lithobraking is an ingenious term for "fuck it, we'll just crash into the planet".
Somehow I think it will be easier to get some form of suspended animation working than to develop a functioning FTL drive.
Seven point six two micron: Full Metal Ja- er, sorry, just 7.62 microns.
Looking at the photos in the referenced article, the fourth picture, showing the solar sail fully extended with all kinds of nice wonderful colors (photo from a perpendicular angle) cannot have been shot from the same camera as the other photos. Different color saturation, different focus, different depth, different starfield luminosity, a rather idealized picture of the earth. Offhand, I think this is an artistic or fictional or Photochop representation, and, it is not labeled as such.
It's nice that the Japanese have launched a sail, but that hoked up photo just killed it for me.
The ship in Poul Andersen's The Makeshift Rocket uses beer for propellant.
You can't top that. You're always on the right heading, see? Heading froth into the stars!
Solar sails, indeed. [sniff!]
I've fallen off your lawn, and I can't get up.
You don't know how thick it is?
If they said .00762mm, you still wouldn't have been able to visualize it anyway.
This is how you visualize it:
It's 1/10 the thickness of a human hair. Now get out.
--
BMO
Prior art:
The Wind from the sun - Arthur C Clarke
The Mote in God's Eye - Niven/Pournelle
The Flight of the Dragonfly - Robert L Forward
Not to mention an episode of DS9 where Sisko recreates a Bajoran solar sail.
Ron Jeremy.