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NASA To Demonstrate Largest-Ever Solar Sail in Space

timothy posted more than 2 years ago | from the they've-pointed-her-bow-to-the-southern-star dept.

NASA 91

Zothecula writes "NASA's upcoming Technology Demonstration Missions are intended to 'transform its space communications, deep space navigation and in-space propulsion capabilities.' Three project proposals have been selected for these missions, which should be launching in 2015 and 2016. One of those projects will involve demonstrating a mission-capable solar sail. While NASA has recently tested a solar sail measuring 100 square feet (9.29 square meters), this one will be the largest ever flown, spanning a whopping 409 square feet, or 38 square meters."

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NASA, I am disappoint (1, Insightful)

Reverand Dave (1959652) | more than 2 years ago | (#37553756)

Is this something that Neil Armstrong would be disappointed about? I think this is some pretty cool news myself, even though I don't exactly believe it to be the best use of government funds ATM.

Re:NASA, I am disappoint (1)

khallow (566160) | more than 2 years ago | (#37553910)

While fiscal prudence should be happening in all government agencies, including NASA, the solar sail is a very interesting piece of technology that should have been explored decades ago. I would suggest that it would be a much more effective use of funds, restricted to NASA, than the SLS (Space Launch System) heavy lift proposal that was aired a couple of weeks ago.

The key advantage is that the propulsion system doesn't run out of fuel. As long as it is exposed to sunlight, one can maneuver it around the Solar System (though propulsion is very weak far away from the Sun). That allows for projects that can survey dozens of objects per probe in the Asteroid Belt, for example.

Re:NASA, I am disappoint (1)

CanHasDIY (1672858) | more than 2 years ago | (#37554578)

The key advantage is that the propulsion system doesn't run out of fuel.

Perhaps; but that doesn't change the fact that it still costs a lot of money [nasa.gov] and fuel [nasa.gov] to break free of the gravity well.

Putting the cart before the horse, if you ask me.

Re:NASA, I am disappoint (1)

LifesABeach (234436) | more than 2 years ago | (#37555622)

When it comes to money spent, NASA is still the Red Headed Step Child. But from my backyard view of the Multi-verse, humanity currently comprehends 3 curious methods to climb out of our gravity well. Rockets, Elevator, and Anti-Gravity. One works,(but NASA Administrators act like Edith Bunker and won't use Burt Rutan's solution set). The Elevator is still being developed, and looks to be serviceable, eventually, given humanities comprehension of applied Newtonian Mechanics. Anti-Gravity is still the High School Prom Royalty that can not see me for dirt. The first two are mechanically problematic; but the third one, oh the third one, is the one I still have thoughts for.

Re:NASA, I am disappoint (1)

scottrocket (1065416) | more than 2 years ago | (#37559180)

When it comes to money spent, NASA is still the Red Headed Step Child. But from my backyard view of the Multi-verse, humanity currently comprehends 3 curious methods to climb out of our gravity well. Rockets, Elevator, and Anti-Gravity. One works,(but NASA Administrators act like Edith Bunker and won't use Burt Rutan's solution set). The Elevator is still being developed, and looks to be serviceable, eventually, given humanities comprehension of applied Newtonian Mechanics. Anti-Gravity is still the High School Prom Royalty that can not see me for dirt. The first two are mechanically problematic; but the third one, oh the third one, is the one I still have thoughts for.

Don't forget mass-drivers/electromagnetic launchers. I am not a physicist, but it seems to me that EM launchers (of some sort) should be an area of more than passing interest, for both ground- and space-based launches. Oh yeah,$$...Forgot about that.

Re:NASA, I am disappoint (1)

Skywolfblue (1944674) | more than 2 years ago | (#37560006)

Friction is a HUGE problem for mass drivers. It's pretty much completely impractical to accelerate something to Escape Velocity in the lower atmosphere because the air resistance will fry anything at that speed. Also, unless you build an absurdly (I mean REALLY absurdly) long track, no person is going to be able to survive the G forces. Now it'd be great for say the Moon, or other places with low to no atmosphere.

Re:NASA, I am disappoint (1)

scottrocket (1065416) | more than 2 years ago | (#37560734)

Yeah, over the years I've seen vaporplans for absurdly long rails; however, since the projectile pops out of the thickest parts of the atmosphere in just a few seconds, it seems to me that a sacrificial, ablative shield (like an attritive, onion skin) could possibly sink away the "frying" heat. Who knows, maybe the sheer pressures of the airflow would force the ablated vapors into a boundary layer around the rest of the craft, thus protecting it from friction, and possibly sponsoring a transient, superlaminar flow, reducing friction (I suppose I should have inserted a "Star Trek Jargon Alert" into this post earlier :^) ).

Re:NASA, I am disappoint (1)

khallow (566160) | more than 2 years ago | (#37562368)

Perhaps; but that doesn't change the fact that it still costs a lot of money and fuel to break free of the gravity well.

If you're ok with passing through the Van Allen belts a bunch of times, then you don't need to break free of the gravity well, you just need to get into low Earth orbit. Past that, solar sails can then take you anywhere else in the Solar System. Not everything can solve the cost of putting things into space, but solar sails do help with the problem you mention above for very radiation insensitive payloads.

Re:NASA, I am disappoint (1)

CanHasDIY (1672858) | more than 2 years ago | (#37568436)

My point was, focusing resources on space-based propulsion systems before first finding a more cost effective and efficient way to get to space in the first place, is like trying to fly an airplane without first attaching the wings.

IMO, of course.

Re:NASA, I am disappoint (1)

Ogive17 (691899) | more than 2 years ago | (#37554238)

So should the government cut all funds to science research and development? We really didn't need those jobs anyway.

Re:NASA, I am disappoint (1)

Reverand Dave (1959652) | more than 2 years ago | (#37554394)

Last time I checked, NASA isn't the only agency that does science. NOAA [noaa.gov] comes to mind as well as the NSF [nsf.gov] just to name a few. I my point is that there are terrestrial concerns that are a tad more pressing for the immediate term. Drop the hyperbole.

Re:NASA, I am disappoint (1)

M8e (1008767) | more than 2 years ago | (#37554534)

Not Safe For GOVernment?

Re:NASA, I am disappoint (1)

Doc Ruby (173196) | more than 2 years ago | (#37555024)

Oh, so as long as there's just one agency, science and employment will grow just fine. That is your hyperbole - or rather hypobole.

Look, why don't you concentrate on the $TRILLIONS in military/intel expenses and the $TRILLIONS in rich people tax cuts that are actually killing our budgets and economy, instead of the fractions of a percent that are the good reasons we have anything left to work with.

Re:NASA, I am disappoint (1)

Reverand Dave (1959652) | more than 2 years ago | (#37555378)

I don't think I stated that "defense" spending or tax cuts for the "job creators" wasn't a huge waste of taxpayer dollars and is in fact sinking our economy in an almost criminal fashion. I didn't advocate nixing NASA, but I think that our sights should be set a little closer to home. Again, jumping to the ultimate conclusion of any statement is hyperbole and you have just engaged in it yourself.

Re:NASA, I am disappoint (1)

Doc Ruby (173196) | more than 2 years ago | (#37555810)

You need to look up the definition of hyperbole [reference.com] .

I didn't say you said anything about military spending or tax cuts. What I said is that nickel/diming the most productive public investments is a waste, when those other sources of crisis are begging for attention. Every minute you spend talking about cutting NASA is a minute you're not talking about cutting military/intel or collecting taxes from rich people. If you can link to somewhere you've asked for that real benefit somewhere in the past month or six, I'll calm down. Otherwise I'll stick to the reasonable assumption that you just pick on NASA instead of where the problem really lies.

Re:NASA, I am disappoint (1)

Reverand Dave (1959652) | more than 2 years ago | (#37556970)

have fun with that [ientry.com]

Re:NASA, I am disappoint (1)

Doc Ruby (173196) | more than 2 years ago | (#37557132)

Otherwise I'll stick to the reasonable assumption that you just pick on NASA instead of where the problem really lies. Jerk.

Re:NASA, I am disappoint (1)

Reverand Dave (1959652) | more than 2 years ago | (#37558006)

you're funny [motifake.com]

SIX POINT TWO TRILLION DOLLARS A YEAR (2)

Shivetya (243324) | more than 2 years ago | (#37554522)

that is the estimated combine budgets of every form of government in the United States. Federal, state, and local.

and people seem to have a never ending list of wants, yet it is so very disappointing what little we are getting for that expenditure. So little of the money goes to non-vote buying schemes that we become desperate to find dollars to spend on something right.

There is no best use of government funds atm because atm the Congress controls nearly fou trillion of it, a good amount that doesn't even exist yet and our descendants will have to pay, and they could not even agree on finding three billion dollars in offsets for increased spending by FEMA.

We blow through NASA's budget in two days of spending at the Federal Level. These missions are nothing. The waste alone in Medicare/Medicade (estimated at over one hundred billion a year) would put men on Mars. Someone will bring up the wars but those are a distraction used by one side to hide the waste of government and used by another to buy votes from their side. Never vote for a D or a R candidate, you simply kick the ball down the street.

Re:NASA, I am disappoint (0)

Anonymous Coward | more than 2 years ago | (#37554536)

With MESSENGER (http://en.wikipedia.org/wiki/MESSENGER), NASA engineers discovered that they could get significant fuel savings by using the solar panels as sails. While solar sails aren't terribly effective for outer system craft, they appear very useful for inner system work; given that the technology can reasonably be expected to provide significant savings and improve our ability to deploy probes, as well as having no few "practical" uses... yes, I'd say this is a very good use of government funds.

Re:NASA, I am disappoint (1)

thed8 (1739450) | more than 2 years ago | (#37565392)

Disappointed is right. China launches a new part of a lab now, and maybe possibly in 10 or 12 years we get to launch Humma Kavula's nose rag..... Achoo

sure. (0)

Anonymous Coward | more than 2 years ago | (#37553760)

> NASA To Demonstrate Largest-Ever Solar Sail in Space...

"...in four years. Maybe. We'll see..."

first!

An important step towards propusion (4, Informative)

Covalent (1001277) | more than 2 years ago | (#37553812)

At this size (0.000038 km^2) the amount of thrust generated by this sail will be 0.0003477N. If the total mass of sail and attached spacecraft is 100kg, then the acceleration will be 3.477E-6 m/s^2. After a month at this acceleration, the craft will be traveling at 9m/s. That's only about 20mph. Not very fast, but an important proof of concept.

Re:An important step towards propusion (0)

Anonymous Coward | more than 2 years ago | (#37553962)

Correct me if I'm wrong but the photons will have an accelerating effect, so even if it's 20mph after one month, wouldn't it be faster than 40mph in 2 months? I.e. will speed then be superlinear? With nothing slowing it down (besides its own mass) the particles will keep nudging the object ever faster, and since it's in a field of basically limitless "fuel" it'll achieve incredibly fast speeds... after a long while.

Re:An important step towards propusion (1)

Covalent (1001277) | more than 2 years ago | (#37554070)

In open space, yes. But 20mph is not enough to escape Earth's gravity. So if this is in orbit, it'll stay in orbit. But this is more a proof of concept than an actual speed test.

Re:An important step towards propusion (1)

AlecC (512609) | more than 2 years ago | (#37554422)

No - it accumulates continually, provided it is high enough to avoid atmospheric drag. OK, the velocity difference between LEO and escape velocity is still of the order of 20,000 mph, so it would take 1,000 months to escape from Earth's gravity well. But what is eighty odd years on the cosmic scale?

Re:An important step towards propusion (0)

Anonymous Coward | more than 2 years ago | (#37554730)

Put simply, a 20'x20' solar sail isn't enough for even 1kg of mass, but it is enough to study some of the basic physics. Something needs to be made on the order of 100x100 meters to be useful (225x larger). That would give 2km/sec delta-v per month - only six months to get out of Earth's gravity well. The relative size of the sail to the probe will look ridiculous.

Re:An important step towards propusion (0)

Anonymous Coward | more than 2 years ago | (#37555050)

So I don't get it. If it is in orbit around the earth and the sun is pushing it, what happens when it comes around the other side of the planet and is going towards the sun? Will it slow down?

Re:An important step towards propusion (1)

Coren22 (1625475) | more than 2 years ago | (#37555644)

At that point you turn the sail. Sailboats don't stop when going near to direct into the wind; some sailboats can even come as close as 5deg off of directly at the wind. Think of it as a big sailboat, the only time it slows down is in that 10deg area directly towards the sun.

Re:An important step towards propusion (0)

Anonymous Coward | more than 2 years ago | (#37562650)

The one issue that I have with that, is that to beat, you need a side/center board to keep the craft from moving sideways. So, how does this keep from moving sideways? It seems like they would have to accept some amount of losses on it.

BTW, grew up racing a c-scow with a sail that was cut on the leech. That would hurt us a bit on the run, but allowed us to get 5 deg, which was about 1-2 deg closer than our competitor. .....
Up. :)

Windbourne - Moderating.

Re:An important step towards propusion (1)

captainpanic (1173915) | more than 2 years ago | (#37554634)

Correct me if I'm wrong but the photons will have an accelerating effect, so even if it's 20mph after one month, wouldn't it be faster than 40mph in 2 months? I.e. will speed then be superlinear? With nothing slowing it down (besides its own mass) the particles will keep nudging the object ever faster, and since it's in a field of basically limitless "fuel" it'll achieve incredibly fast speeds... after a long while.

If the acceleration is constant, then velocity increases linearly.
But the craft will move away from the sun, photon density will decrease, so the acceleration will actually decrease, and the velocity will increase with a less-than-linear amount in time.

I think that the mass of 100 kg that we're working with in this little example is a bit too much.

Re:An important step towards propusion (1)

rgbatduke (1231380) | more than 2 years ago | (#37556518)

Right, but as the craft moves away from the Sun (in particular) solar gravity drops off at exactly the same rate that solar flux drops off (both 1/r^2). OTOH the craft isn't trying to pull directly away from the Sun, it is angling the sail to get a maximum transverse acceleration to increase its orbital speed. OTOOH as its transverse speed increases F_\perp v_\perp (to r) increases with v_\perp as F_\perp remains nearly constant, so the power delivered to the mass is nearly constant. Eventually it all makes my head hurt and want to turn to matlab to just integrate the EOM and see what happens.

The long and short of it (or rather, thick and thin of it) is that a 20x20 sail is a practical joke (or rather, practically a joke) good for little but to prove a concept that doesn't really require much proof. It's the engineering and scaling that are problems. A sail one micron -- 10,000 atoms or so -- thick means that 1 m^3 of sail material is 10^6 m^2 of sail. 1 m^3 has a mass of at least 1, more likely 2 metric tons -- GENEROUSLY call it 1000 kg. That is thin enough that Uri Gellar could punch holes in it just by grimacing from ten meters away. Now imagine something really exotic -- spun carbon nanotube fibers, spider silk -- to use as rigging, and make it also so thin that harsh words would snap it, add some rather complicated servomotors to pull in and extend the rigging synchronously and perfectly (as any sort of defect in the sail will tear it or snap the rigging lines), add a computer to control it all, add power to run the servomotors (solar, sure, but add solar panels and batteries), add a housing -- and you're at LEAST at another metric ton of dead weight before you get to a real payload.

Your sail generates around 3.5 N of thrust, optimally tipped, at Earth orbit (assuming round number I_sun = 1500 W/m^2). Add a 1.5 metric ton payload (so the total mass is 3.5x10^3 kg and you have a convenient a_t = 10^{-3}. Low orbital speed is roughly 0.7 escape speed, call it 7 km/sec, so it takes you around 4000 m/sec / 10^3 m/sec^2 \approx 10^7 sec to escape from the Earth (probably 2x this or more, actually, given probably non-optimal tacking). \pi \times 10^7 seconds is a year, so call it a year to reach escape speed with a bit over a metric ton of payload and a ratio of maybe 2:1 sail and support to payload. Quibbling a bit is possible, but this is (if I did arithmetic right, always doubtable:-) order of magnitude reasonable.

The good news is that once you are in Earth's orbit it is free. The bad news is that getting to low Earth orbit already cost you half the energy required to escape, and that's a lot of energy -- moreso since you have to spend the energy to lift the sail, not just the payload, with all of those early nonlinearities multiplied by 3+. A win, but not an enormous one, and a rocket lets you step right up to escape speed and get there MUCH earlier.

Not a great way for humans to travel, actually. Maybe a good way to send food and air on ahead to waystation orbits en route to Mars, if you don't mind taking a decade or so for your food etc to get there. Perhaps a good way for relatively large, permanent research robots to float around in the solar system over century timescales, useful "forever" (or until the sail develops a defect and rips in half, IMO likely a long time before forever directly exposed to CMEs and the solar wind and high UV, all of which make the MATERIAL of the sail likely to come apart (and embrittle) in years to a decade, assuming almost any kind of flexible e.g. aluminized polymer as a base. Indeed, I suspect that the solar wind might exert MORE force on the sail than sunlight at certain times, probably in a disastrous storm-at-sea sort of way.

rgb

Re:An important step towards propusion (1)

khallow (566160) | more than 2 years ago | (#37563202)

The good news is that once you are in Earth's orbit it is free. The bad news is that getting to low Earth orbit already cost you half the energy required to escape, and that's a lot of energy -- moreso since you have to spend the energy to lift the sail, not just the payload, with all of those early nonlinearities multiplied by 3+. A win, but not an enormous one, and a rocket lets you step right up to escape speed and get there MUCH earlier.

Energy is insignificant. For a rocket (or indeed anything that moves by throwing out reaction mass), the real restriction is delta v. The mass fraction, the amount of the rocket that can be something other than propellant is proportional to some number raised to the delta v power. If you double the delta v, then you have to square the mass fraction (which is already significantly less than 1) to get the new mass fraction.

This means that for rockets which operate at very low mass fractions, any reduction in the delta v requirements can lead to substantial gains in mass fraction put up. So launching a radiation insensitive payload into LEO and pushing it on via a solar sail can indeed put more mass in a final trajectory than launching directly via rocket. This is somewhat dirtied by the Oberth effect, where thrust deep in a gravity well for an escaping object, provides greater overall delta v than thrust higher up the gravity well. Rockets can provide most of the necessary thrust while the vehicle is still near Earth. That provides a significant delta v advantage.

The real play for solar sails is their theoretical ability to provide thrust for decades. As you note later, this may be illusory with damage to the thin sails greatly curbing their lifespan. But if it can happen, then you have a lot of options for missions that can't be done with chemical rockets (and perhaps not with efficient solar electric propulsion either).

Re:An important step towards propusion (4, Informative)

rolias (2473422) | more than 2 years ago | (#37554762)

Except that the article is wrong. The sail will be 38m wide, or 1444m^2. That's 0.013N: 2 * (38m)^2 * 1368W/m^2 / (300,000,000m/s)

Re:An important step towards propusion (0)

Anonymous Coward | more than 2 years ago | (#37555978)

Thanks for pointing that out. That 38m^2 figure did seem rather underwhelming.

Re:An important step towards propusion (1)

schlachter (862210) | more than 2 years ago | (#37556772)

Yes, but the point is that it will add another 20mph the next month and so on in a cumulative fashion...and light speeds the limit (in theory)...and it could be combined with other propulsion tech such as ion energy or gravity assists.

"spanning a whopping 409 square feet..." (4, Insightful)

Cornwallis (1188489) | more than 2 years ago | (#37553864)

Whopping? That's only about four times larger. Certainly not "whopping".

Re:"spanning a whopping 409 square feet..." (0)

Anonymous Coward | more than 2 years ago | (#37553948)

No kidding. It's going from 10'x10' to 20'x20'

Re:"spanning a whopping 409 square feet..." (1)

Anonymous Coward | more than 2 years ago | (#37554042)

Whopping? That's only about four times larger. Certainly not "whopping".

That's what she said

Re:"spanning a whopping 409 square feet..." (0)

Anonymous Coward | more than 2 years ago | (#37554096)

How many football fields is one whopping?

Re:"spanning a whopping 409 square feet..." (1)

MadKeithV (102058) | more than 2 years ago | (#37554420)

How many football fields is one whopping?

Approximately 1000 Volkswagen Beetles, or 0.15 Libraries of Congress.

Re:"spanning a whopping 409 square feet..." (1)

kimvette (919543) | more than 2 years ago | (#37556118)

How many empty Dorito bags is it, though? To specify: neither crumpled up nor laid out flat.

Re:"spanning a whopping 409 square feet..." (2)

LWATCDR (28044) | more than 2 years ago | (#37554222)

Sorry you are wrong. In the Slashdot system of universal measurements you only have to have a 2x expansion to == a whopping. An 8x or greater requires the addition of the prefix great and a 64x an additional prefix of huge as in a huge great whopping. You transition to hugenormus once the surface area == one standard library of congress rendered in courier 10 point font, double sided on A4 sized paper, at standard temperature and pressure.
Hope that cleared it up for you.

Re:"spanning a whopping 409 square feet..." (1)

nschubach (922175) | more than 2 years ago | (#37554302)

Thanks for the clarification, but I have one other question on a recently used measure:

What about ton? ("I have a ton of iso/mp3s")

Re:"spanning a whopping 409 square feet..." (1)

moondawg14 (1058442) | more than 2 years ago | (#37554488)

We need to know which "ton" you're speaking about. Is it a shit-ton, a metric shit-ton or a butt-ton?

Re:"spanning a whopping 409 square feet..." (1)

Dishevel (1105119) | more than 2 years ago | (#37554564)

I have a question concerning "Butt-Load".
What type of diaper is used to define the term?

Re:"spanning a whopping 409 square feet..." (1)

LWATCDR (28044) | more than 2 years ago | (#37555708)

A ton of digital data is that can not fit on common mass storage costing less than $60. That is the the technical use. So in say 1983 it would have been about two mega bytes using Elephant floppies at around 177k each In the colloquial use. Today it is about 1 TB. Also anything large fraction of a SLOC "Standard Library of Congress" would be a ton of. The less formal use means "so much I have no idea what I have", "I have a netfix account and rip and send", or "I have more than you do".
 

Re:"spanning a whopping 409 square feet..." (1)

AlecC (512609) | more than 2 years ago | (#37554432)

Unless it is expressed in football pitches, or maybe micro-Belgiums, how can I possibly understand it?

Re:"spanning a whopping 409 square feet..." (0)

LWATCDR (28044) | more than 2 years ago | (#37555572)

Football pitches? What are you a 10 year old girl or a sissy EU type. This here board was started in Michigan in the U.S. of the freaking A. We use football fields here! micro-Belgiums? Well since everything in Europe is small and frankly unimportant a micro-Belgium== a smige.

Re:"spanning a whopping 409 square feet..." (1)

Bucky24 (1943328) | more than 2 years ago | (#37556302)

It takes bigger balls to play football in Europe ;)

Re:"spanning a whopping 409 square feet..." (2)

sir_eccles (1235902) | more than 2 years ago | (#37554662)

Well, how big is YOUR solar sail?

Re:"spanning a whopping 409 square feet..." (1)

stackOVFL (1791898) | more than 2 years ago | (#37560476)

Don't need one. I use two swallows with a string tied under the dorsal guiding feathers. I made small air tanks from empty coconuts. Rocket science, meh.

Microwave Power (2)

cobrausn (1915176) | more than 2 years ago | (#37553888)

If Sim City is to be believed [mastermarf.com] , I expect this to go into production as a viable energy source around 2020. As long as they don't cut funding. They would regret that.

Re:Microwave Power (1)

AikonMGB (1013995) | more than 2 years ago | (#37553994)

Solar sail, not solar collector.

Aikon-

Re:Microwave Power (1)

cobrausn (1915176) | more than 2 years ago | (#37554080)

Ah. Maybe I should RTFA first next time. :-(

Re:Microwave Power (1)

Bucky24 (1943328) | more than 2 years ago | (#37559418)

Or at least the title...

409 sq. ft.? (1)

wisebabo (638845) | more than 2 years ago | (#37554140)

Ok I know I RTFA. But just 409 sq. ft.? (and no I don't think they meant 409 ft. square, they also said 38 sq. meters). I'm really hoping that's a journalistic error because 409 sq. ft. is just 20x20 feet! I think the sun shield used on the hopefully-not-to-cancelled JWST is bigger than that. And there are 5 layers!

In terms of size there are lots of things solar sail-ish that are bigger than that. Like the solar arrays on the ISS. Or how about Echo 1, a giant slivered balloon that was put into orbit to reflect radio waves (before there were reliable transponders I guess), it was over 100 feet in diameter. Of course the real key is not just size but the ratio of area to mass, perhaps that's what makes this special. Also perhaps maybe they've figured out a good way to control large flimsy objects (spinning? Inflatable spars?). Still they need (eventually) to be thinking about KILOMETERS (I mean miles!).

Their idea as using it to capture space junk won't work except for the very lightest of space junk, everything else will just riddle it with holes. I've suggested before that AEROGELS would be an ideal material for capturing (or slowing down) hypervelocity fragments just like the Stardust and Genesis probes did. But that presumes an efficient way of making it IN ORBIT that recycles (or doesn't need) the solvents needed.

By the way, in my brief scan of TFA, I don't recall seeing what the mission profile was. Is it intended for LEO? In which case controlling it as it goes through a sun-earth cycle every 90 minutes is going to be difficult. Hopefully they'll put it in a high orbit or even an escape trajectory so that it'll have some "running" room. (I think there was a little Japanese solar sail that got that). I'm really hoping there's an error in the article, a properly designed (even with today's technology) large sail launched on the correct trajectory could accelerate up and out of the inner solar system. It would be great if it could give the New Horizons probe, even with its 5(?) year head start, a race to Pluto!

Ah, just thinking about this has me remembering the Arthur C. Clarke short story about the solar sail race to the moon.

Re:409 sq. ft.? (2)

rolias (2473422) | more than 2 years ago | (#37554556)

The Gizmag article was... imprecise. The sail will be a square 38m wide, with an area about 1400 m^2. It's based on a 20m wide sail L'Garde built and tested for NASA in 2005. More info here: http://www.nasa.gov/offices/oct/crosscutting_capability/tech_demo_missions.html [nasa.gov]

Re:409 sq. ft.? (1)

wisebabo (638845) | more than 2 years ago | (#37554864)

Thank you very much, that was a MUCH more informative link.

I especially like the "station keeping" applications, over the poles or at pseudo-lagrangian points. Someday, they could perhaps use this technology for station keeping directly over the SUN!

Alas, I'm afraid that thanks to the debacle of the space shuttle and ISS, space exploration may have been sent back by a generation (maybe longer if you consider the loss of "momentum" in political will). What I had hoped to see in my lifetime will now only be possible in my children's. By then maybe they'll be so self-involved with "social media" that they'll have no time for something as un-instantaneously gratifying as exploring the Universe. Then again, who am I to blame? I'm the one spending my time making posts to Slashdot! :(

Re:409 sq. ft.? (1)

rolias (2473422) | more than 2 years ago | (#37566822)

Glad to help. Yeah, a sufficiently large (thrust) and lightweight (acceleration) sail could counteract and even exceed the sun's gravity. A sail mass/area of ~1.5 g/m^2, which accelerates at ~6 mm/s^2 at Earth would achieve this. Lower performance sails could still linger over the sun in "halo" orbits.

I think it's an opportunity when large organizations fail do do something new. They get out of the way, giving more flexible and innovative parties have a chance. I think expansion into space has, in part, been held back for a generation or two because we expected government space programs to do it all for us: throw enough tax dollars at it, and it will happen. It didn't, and now parties like SpaceX are making great strides - with government cooperation.

Re:409 sq. ft.? (1)

wisebabo (638845) | more than 2 years ago | (#37554692)

Oh, by the way, the name of the story was "The Wind from the Sun".

Re:409 sq. ft.? (1)

element-o.p. (939033) | more than 2 years ago | (#37556298)

Thanks for posting that. I loved A.C.C.'s stories when I was a kid, but I don't remember reading a story about a solar sail race to the moon. I was about to search for it (it sounds interesting), but you've saved me the work :)

Re:409 sq. ft.? (1)

camperdave (969942) | more than 2 years ago | (#37555332)

Both Echo 1 and Echo 2 experienced solar sail effects. Anything, regardless of size or shape, will experience solar sail effects. However the effects are generally negligible unless the object has a huge area relative to its mass.

Frist 5top (-1)

Anonymous Coward | more than 2 years ago | (#37554150)

But noW thoey're

Re:Frist 5top (0)

Anonymous Coward | more than 2 years ago | (#37554376)

Yes

Headline in 2016 (1)

elrous0 (869638) | more than 2 years ago | (#37554164)

"Press Has Forgotten Five-Year-Old NASA Promise"

Sorry but the Japanese deployed a larger one. (1)

jklovanc (1603149) | more than 2 years ago | (#37554298)

In July 2010 the Japanese deployed IKROS [wikipedia.org] with a surface area of almost 2200sq.ft. That is almost 5.5 times the size of this sail. Maybe Gizmag should learn to use Google.

Re:Sorry but the Japanese deployed a larger one. (1)

Wingfat (911988) | more than 2 years ago | (#37554388)

for one that is a Wiki site.. on the 2nd note, it says it was the first? lies.. the Russains were the first in 1993. and the Russians were the ones that came up with the idea of it. just like the light bulb.. we invented it.. they make it better.

Re:Sorry but the Japanese deployed a larger one. (1)

rolias (2473422) | more than 2 years ago | (#37555262)

The Russians deployed the Znamya [space.ru] space mirror from a Progress resupply ship in 1993, and tried a second time in 1999. The Progress propelled and steered it to reflect a spot of light down on the Earth, so it didn't do actual solar sailing. IKAROS [www.jaxa.jp] has that distinction. This new mission [nasa.gov] will actually test a 38m x 38m sail, so it will be the largest.

Re:Sorry but the Japanese deployed a larger one. (1)

camperdave (969942) | more than 2 years ago | (#37555318)

just like the light bulb.. we invented it.. they make it better.

You're British?

Re:Sorry but the Japanese deployed a larger one. (1)

Wingfat (911988) | more than 2 years ago | (#37555406)

Scott/Irish/Norse/NativeAmerican - you pick. Swan did make one first.. but Edison made the long lasting Filament

Re:Sorry but the Japanese deployed a larger one. (1)

camperdave (969942) | more than 2 years ago | (#37556608)

Scott/Irish/Norse/NativeAmerican - you pick. Swan did make one first.. but Edison made the long lasting Filament

Swan who? Edison's cohort? Not by a long shot. People were making incandescent light bulbs before Swan was even born. But why let a few stray facts spoil such a pervasive American Myth.

Re:Sorry but the Japanese deployed a larger one. (0)

Anonymous Coward | more than 2 years ago | (#37560470)

Then stop arguing like a child and give us some names, some references, and citations. Just saying "I'M RIGHT AND YOU'RE WRONG!" doesn't make you right, it makes you a child.

Re:Sorry but the Japanese deployed a larger one. (1)

camperdave (969942) | more than 2 years ago | (#37561480)

1802, Humphry Davy created the first incandescent light by passing the current through a thin strip of platinum
1835, James Bowman Lindsay demonstrated a constant electric light at a public meeting in Dundee, Scotland.
1840, British scientist Warren de la Rue enclosed a coiled platinum filament in a vacuum tube and passed an electric current through it.
1841, Frederick de Moleyns of England was granted the first patent for an incandescent lamp, with a design using platinum wires contained within a vacuum bulb.
1845, American John W. Starr acquired a patent for his incandescent light bulb involving the use of carbon filaments.
1847, Edison was born.
1851, Jean Eugène Robert-Houdin publicly demonstrated incandescent light bulbs on his estate in Blois, France.
1854, Heinrich Göbel claims to have designed an incandescent light bulb with a thin carbonized bamboo filament of high resistance, platinum lead-in wires in an all-glass envelope, and a high vacuum.
1872, Russian Alexander Lodygin invented an incandescent light bulb and obtained a Russian patent in 1874. He used as a burner two carbon rods of diminished section in a glass receiver, hermetically sealed, and filled with nitrogen.
1874, a Canadian patent was filed by a Toronto medical electrician named Henry Woodward and a colleague Mathew Evans. They built their lamps with different sizes and shapes of carbon rods held between electrodes in glass cylinders filled with nitrogen.
1878, Joseph Swan "Invents" the light bulb.
1879, Thomas Edison "Invents" the light bulb.

Re:Sorry but the Japanese deployed a larger one. (0)

Anonymous Coward | more than 2 years ago | (#37558168)

IKAROS only had a surface area of 200 square meters... This one has a surface area of 1444 square meters.

Re:Sorry but the Japanese deployed a larger one. (1)

RivenAleem (1590553) | more than 2 years ago | (#37566336)

Gizmag is wrong, but not in the way you think. The sail is 38m in width, 1444m^2 area or 15,542.6089sq.ft

Oh wow! (0)

Anonymous Coward | more than 2 years ago | (#37554316)

A flimsy film in space! We'll be knocking on Andromeda's door by next week! Oh yeah! Look out, space, the short-lived balding monkeys from Earth with arthritis are climbing in their tin cans and nothing can stop them! (Except reality).

Re:Oh wow! (0)

Anonymous Coward | more than 2 years ago | (#37554456)

hehe we are cute :-)

Star Trek DS9 - Bajoran solar-sail vessel anyone? (1)

Wingfat (911988) | more than 2 years ago | (#37554324)

I always thought Solar sails would be awesome after seeing the DS9 epsiode where Commander Sisko constructed his own lightship and took his son, Jake Sisko, along for the maiden voyage. http://www.startrek.com/database_article/bajoran-solar-sail-vessel [startrek.com]

Re:Star Trek DS9 - Bajoran solar-sail vessel anyon (0)

Anonymous Coward | more than 2 years ago | (#37560668)

It pays to not base your analysis of modern science on science fiction. You'll often be disappointed.

Complete story (2, Informative)

Anonymous Coward | more than 2 years ago | (#37554330)

For the complete story, see the NASA announcement from August 22nd: http://www.nasa.gov/offices/oct/crosscutting_capability/tech_demo_missions.html

The sail is 38x38m. Two 20x20m sails were developed for NASA in 2005 by L'Garde and ATK. The thrust on the sail is approximately: 2 * (38m)^2 * 1368 W/m^2 / c ~= 0.01 N

Re:Complete story (0)

Anonymous Coward | more than 2 years ago | (#37554952)

24,800 square feet... A bit more significant

private sector is already doing this (0)

Anonymous Coward | more than 2 years ago | (#37554722)

http://www.planetary.org/programs/projects/innovative_technologies/solar_sailing/

Solar Sail can be very useful (1)

aurizon (122550) | more than 2 years ago | (#37554868)

A small thrust like this can be used to keep the station up permanently and even to adjust the orbital attitude as needed.

This will save those missions to send up maneuvering fuel from time to time and save lots of $$

Funding (1)

RogerWilco (99615) | more than 2 years ago | (#37554910)

Like NASA will still be funded then. I don't think NASA will make it past 2013 if even FEMA funding is in question.

That's Not Whopping (1)

Doc Ruby (173196) | more than 2 years ago | (#37555068)

spanning a whopping 409 square feet, or 38 square meters.

That's not "whopping". In microgravity and near vacuum, "whopping" would be a square kilometer, or a dozen square kilometers. Accelerating probes into outer solar orbits in a few years, dropping network nodes along the way, charging fuel stations for planetary exploration, eventually capturing asteroids for making machines that exploit other planets' resources, eventually colonizing the whole system. The future of inhabiting space is long, but there's little reason to wait for a truly "whopping" sail to get us started.

That's A Good Thing! (1)

Jane Q. Public (1010737) | more than 2 years ago | (#37555150)

I sure am glad they are going to demonstrate it in space!

Demonstrating it here on Earth would cause all kinds of problems.

Actual Size (0)

Anonymous Coward | more than 2 years ago | (#37557566)

Article is wrong.
Size of new solar sail is 38m * 38m = 1444 square meters.
155 times bigger than the old one.

There are people shown next to the sail, there is NO WAY that thing is only 6.164414m * 6.164414m.

Re:Actual Size (1)

skelly33 (891182) | more than 2 years ago | (#37559280)

/. summary must be wrong.Gizmag itself states in the caption, "this one will be the largest ever flown, spanning a whopping 15,543 square feet, or 1,444 square meters."

I was gonna say - roughly 20x20 feet never sounded so exciting before!

Iridium NEXT payloads? (0)

Anonymous Coward | more than 2 years ago | (#37562158)

It sounds like these will ride as secondary payloads on Iridium NEXT constellation satellites. Is that a vote of confidence for Iridium from NASA?

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