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NASA Proposes Launch Of Solar Sail Vehicle For 2010
outcast341 writes: "Apparently, NASA plans to
launch a solar
sail spacecraft in the year 2010, according to this press release. The the first trip
will take about 15 years, traveling about 58 miles per second. The sail will be 440 yards
in width, and will be constructed of a reflective carbon-fiber material. 'This will be
humankind's first
planned venture outside our solar system,' said Les Johnson, manager of
Interstellar Propulsion Research at the Marshall Center. 'This is a
stretch goal that is among the most audacious things we've ever
undertaken.'" (Read more.)
And if a mere 15 years from now and using technology that's lapping on the safe side of fringedom isn't enough to make you bite, Joseph Rosenblum reminds us, "Not news, but cool: if you havn't seen it, NASA has a Breakthrough Propulsion Physics Program that is a speculative research division looking into the technologies that will one day enable interstellar travel. There's also a 'Warp Drive, When?' FAQ!"
Photons of light have zero rest-mass, but they do have momentum. if the area of a highly reflective (>95%) surface is sufficient, most of the photon's momentum is transfered to the sail and can produce incredible amounts of acceleration. the trick is to maximize surface area (for more propulsive thrust) and reflectivity of the sail, otherwise you wind up with too much photon absorbtion which causes the sail to heat up. the straight forward photon or Light Sail is an old concept that, while promising in the near term since the technology is fairly achievable, there are even more promising sail concepts on the drawing board, like magnetic propulsion sails and plasma sails. A really excellent far-term space sail concept is the StarWisp, which uses a very high power laser to produce thrust over interstellar distances. the StarWisp is huge, and so is the laser needed to provide power to the craft over a distance of several light years. But the concept is entirely feasible. Such a craft could reach Alpha Centauri in less than 50 years.
I'm sure you're just a troll, but that concept of yours depends highly on where the focal point is. With a solar sail, I think it would be at infinity.
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Much less is spent on NASA than professional sports, and professional sports has negative productivity (wastes time), although it does keep the masses in line.
It's not like a project like this would be more expensive than the Space Plane^h^h^h^h^h Shuttle, which probably 90% of the American public thinks is a real space ship -- it can't even get 5% of the radius of the earth in altitude.
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Hmm, was thinking kind of along the same lines.
What about dark matter?
So is the propulsion design based (in part at least) on assumptions about the number of hydrogen atoms in inter-solar space?
Thought I remembered an article not too long ago about some of this theorized 'dark matter' being found. Would be interesting if this solar sail vehicle were to encounter conditions that were unknown/unexpected and forced us to change some of our fundamental assumptions about space.
(or not)
If I were them I'd not unfurl the sail until the device was out of the ecliptic or outside jupiter.
You still have to go through the Kuiper belt though.
-Yarn - Rio Karma: Excellent
It ain't going nowhere. It won't even reach 1/2 a light year out (far enough to look for a planet X canidate - a 10x larger than Jupiter or brown dwarf perhaps).
Even if it carried the standard compliement of NASA porn, ain't nobody gonna see it. 'Cept for V-GER maybe...
This is our chance to DESTROY V-GER well before it gets to the 23rd century and is programmed to destroy all carbon-based life forms!!!
Eat your heart our Captain Kirk.
The article says this solar sail could reach speeds of up to 58 miles per second -- or roughly 200,000 mph. A light year is a mere 5.8 trillion miles, so if the nearest star is just 4.2 light years away, we could be there in only ... [tap tap tap] 13 thousand years!
:), but it's more likely to be even longer.]
.. and if there were a mission (a Pluto-Kuiper Express follow-up, perhaps, or an Oort cloud explorer), it wouldn't get us to even the nearest star any time soon. The oldest space vehicle still in use is on its last legs at 23, after all.
... it would be a snap. Right?
(Well, I may be off by an order of magnitude, I threw this together in Excel after all
The fact is that this is a propulsion systems R&D effort, and as of yet there is no actual mission that would use this light sail
We won't be in shooting distance of the stars until we can get travel time down to, oh, maybe a half a century -- the career lifetime of a scientist.
And there's lots of glib comments in the forum about things like, "oh, by then we'll have mag sails!" My boy, when I was 18, I believed in the stars too. I knew that by the year 2000, knew it in my bones, that we would have people continuously living in earth orbit, and probably a moon base too. Sure, I was a realist -- I knew that it wouldn't be a big spinning Kubrickian wagon wheel. That was beyond our engineering. But hey, we had the shuttle, and we could launch one on a weekly basis
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lake effect weblog
{Network engineer in Chicago--looking for work!}
Science fiction is responsible for conceptualizing a number of things we use every day. The best example of this is probably the satellite, as the people who build them still credit Arthur C. Clarke for coming up with the idea.
NASA's scientific research has resulted in the invention of devices we use every day, arguably benefitting this country far more than they cost us. You own a microwave, right?
Finally, look at the page for Breakthrough Propulsion Research. I read it a few months ago and they tell you how much they're spending. It's not much, and the projects they've awarded (small) grants to are NOT pseudo-science and could have applications here on the ground.
As far as medical research funding goes, I work at a federally-funded cancer research organization and I'll tell you right now we're pretty well covered.
Disclosure: I don't have any connection to NASA in any way, though a job there would be the only thing that could get me to move back to Florida.
-jpowers
-jpowers
Someone already brought this up earlier, but even more promising than the Magsail is the M2P2. There are are problems with the Magsail, especially with the size of the superconducting loop--the needed diameter of which has been estimated from kilometers to hundreds of kilometers.
The material requirements for the M2P2 are more modest. The M2P2 uses a magnetic field generated by a solenoid. This field is then "inflated" with plasma. According to Dr. Winglee:
"...a 200-kilogram probe could deploy a magnetic sail of perhaps 20 kilometers' breadth and attain a velocity of nearly 100 kilometers per second using 50 kilograms of gas and about 1,000 watts of power to keep the plasma envelope filled. Making way at that clip, a craft could reach from Earth to Saturn in less than six months. The Cassini probe now on route to the ringed planet, by comparison, will take seven years..."
For more information, take a look at this article from American Scientist, or try this page at the University of Washington.
It seems like a really cool concept, especially as fast as it goes... But what would they do if one of the sails got hit by some space debris like a rock or something? It would really suck if all that time and effort went to waste because of a hole in the sail.
Hrm loving these
And if a mere 15 years from now and using technology that's lapping on the safe side of fringedom
Current Year: 2000
Year of launch: 2010
Good Math.
I also think it's interesting that it'll pass Voyager in 2018. It's like starting a computing problem that will take 6 years to complete. If you start it today, it'll be done in 2006. If you start it 2 years from now, and computers are twice as fast, it'll be done in 2005.
Anyway, thank God NASA is doing something like this. People talk about privatizing the space industry and what not, but there are still things that only NASA can do.
What will happen if/when we try to deploy a gigantic sail?
Ciao
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FB
This has been discussed a few times already, but...
NASA's track record isn't nearly as bad as the media would have you believe. The news outlets, as with many other things these days, report NASA failures more heavily than the successes. A probe or ship doing exactly what it is supposed to do isn't considered newsworthy enough for a long spot on the national evening news. A probe or ship that gets lost or otherwise malfunctions, complete with an inquiry and all that rot into why it failed? Now that's news! You'll hear little spots about it for weeks. Just like you'll hear about Columbine for months and months and months, and never hear for more than a second about a school that is doing well.
Things that go right just don't get as much attention as things that go badly.
"That's Tron. He fights for the Users."
If you read the actual NASA press release, the goal for the launch is around 2010 but it will take fifteen years (after that) to go 23 billion miles past our solar system. (They hint that the destination is Alpha Centauri).
--Ben
Slashdot is the modern day equivalent of the "telephone game".
NASA has, for unmaned space travel at least, taken a turn in its philosophy. This turn has not been trumpeted by the press. The fact is that some years ago NASA decided, again bear in mind that I'm talking unmanned craft here, it would be cheaper and more effective in the long run to launch cheaply, often, but with a higher failure rate. This is exactly what they have done.
The funny thing is that their failure rate is considerably BELOW what they themselves predicted. They are, in fact, doing a *terrific* job.
Does the press explain this? Not on your life!
Which headline do you think sells more papers?
"Another Mars Probe Vanishes Mysteriously!!!"
( Causing a guy I know to actually think that Martians are shooting them down)
Or,
"Nasa says Lose Rate Still Below Expectations."
" When asked to explain a NASA scientist said, 'We're building quick and dirty, but CHEAP. We're saving the taxpayer money overall, and getting MORE data in the long run. Overall, we're getting far more successes this way than we had dared to hope for."
As for the manned program it really all went to hell back when we dropped the X program for the crash program to the moon.
The crash program did at least end up giving us the only rocker booster we've ever made with a 100% success rate.
By the way, it was designed by one of "our" captured WWII Germans.
" In German, und English, I know how to count down, and I'm learning Chinese, says Werner Von Braun...
One the Rockets are up who cares where they come down, that's not my department, says Werner Von Braun.."
-Tom Lehrer
While the Pioneer and Voyager spacecraft trajectories were planned to leave the system, it was never planned that they'd be at all operational at the time.
Both missions have far exceeded their design parameters. Pioneer 10's mission ended in 1997, but it's still useful; its transmissions are being used to study chaos theory. (Pioneer 11 went dead years ago, when its RTG ran down.) And the Voyagers have been re-assigned to look for the heliopause boundary and study the interstellar environment.
Tom Swiss | the infamous tms | my blog
You cannot wash away blood with blood
Sideways to your angle of movement. The trust from the other star will always be away from that star, unless there would be some giant mirror somewhere. Changing the angle of the sail only determines how much trust you get - but you cannot influence the direction. You cannot apply physics from sailing in water; space has the habit of being nearly frictionless.
-- Abigail
Deep Space 9 == science fiction, really really far out science fiction. Neutrinos travel at roughly the speed of light yet have a very insignifigant mass, they pass right through you every second (3000 or so per second IIRC). They would pass strait through the carbon sail with basically no reaction. Neutrinos are only stopped by dense materials because they have a greater chance of hitting a particle. And besides, it wasn't neutrinos the solar sail caught it was verteron particles from the worm hole.
I'm a loner Dottie, a Rebel.
___
I think they ought to make the sail out of a silicon based material (like a large soap bubble) because it could double as a power source for the space craft (were it conductive enough). A 440 yard (I hope they don't screw up the conversions this time) sail would be able to produce plenty of power for a nice sized probe. Or maybe they could dope the carbon fiber sail with a conductive silicon compound. If they are going to be into massive building projects why not build a large linear accelerator on the moon. With a mile long accelerator and a few watts of electricity you could blast a probe into deep space quite easily.
I'm a loner Dottie, a Rebel.
"...a velocity of nearly 100 kilometers per second..."
:)
It's all very well reaching Saturn in six months but it's a bit of a bummer if you can't stop when you get there
--
Peter
NASA's current budget, adjusted for inflation, is not much lower than what it was in the peak of the Apollo program, but it's mostly wasted on a bloated payroll.
If you are really looking for the reasons for their unimpressive performance you should ask any organizational psychologist. Post-Challenger NASA is a recurring example in all the textbooks.
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Stop worrying about the risks of nuclear power and start worrying about the risks of not using nuclear power.
Even in this information age, where we see not race nor gender, we still must persue hostilities to those who we feel are responsible or are equivilant as their forebearers or perhaps a simple stereotype that propagates across vast oceans and large masses of land.
Beware. The countless entities that bear human form as they press their collective egos upon their world, with all their talents and actions, which as they are, are no more destructive than they are good.
So who are you to separate us into categories and to say that yours are greater than mine? I am proud of my country, but only as much to classify me as a patriot and far less than arrogance. My country has done great things and it will continue to do things that are great. But I will not delude myself in thinking that your country does not also do things that are great.
You think my comments are politically correct? Well they are. As they should be. Because it is the only way for us to coexist in peace. Even that can come to an extreme. As long as we know the truth about ourselves we would no longer be startled when we hear from strangers.
Best Regards,
Everyone.
To tell you the truth I don't know what an analysis of Martian soil will do to effect the way you and the rest of society live their lives.
I CAN, however, list a few ways that that it has effected my life *so far.*
The Transistor/IC/Microchip and hence the Home computer. The PII 400 I'm writing to you with puts more raw computing power on my home desk than all of NASA had *combined* during the Apollo program and is a direct result of that program.
The internet itself, something that many consider the biggest change to the way we live our lives, exists, at least in part, due to the space program. The rest of the responsibility for the internet goes entirely to other "big science" projects.
The WWW and HTML come to us *directly* from the subatomic research people at CERN.
The internet and the WWW alone may end up being worth every penny we've ever spent on big science.
Nomex (tm) fireproof cloth, which saves hundreds of lives every year came directly from the space program.
Carbon Fiber composites. Kevlar. Cheap Titanium.
Modern telecommunications and GPS. Recently a solo around the world sailboat racer was rescued from disaster. Her position could be pinpointed with GPS and her rescuer was notified of her plight by *E-Mail* sent by satellite transmission!
And to wrap it up before I go on and on and on I'll bring up my closing point while directly addressing one of your key concerns.
Great wopping GOBS of big science money is spent on basic medical and biological research. Big science has advance the state of medical knowledge far beyond what anything else ever has, and has saved millions of lives. Much of this research was done directly by NASA. Which is the main thrust of my final point. The money spent by a big project outfit like NASA dosn't ALL go just into the main object of the project. Rockets are the SMALLEST part of the NASA budget. The peripheral research and technological fallout to the public is a just plain HUGE part of "big science."
Could I have told you in advance that a cyclotron would result in the WWW and HTML? No. I'm a scientist, not a psychic. But it did. Other projects will have similar social benifits. I can't tell you what they are yet though, we havn't found out yet, but the record of PAST benfit is huge.
Now we are just begining to synthesis some of what already have. Take Nomex, Kevlar and carbon fiber and *combine* them with big science medical research and you now have millions of people who's lives can be saved by using these to rebuild arteries, rebuild shattered bones, make functional replacement for missing limbs. The list goes on and I'm in danger of not wrapping this up.
Look around you. Think about it.
One more thing: neutrinos are not quite massless, and therefore can't travel at the speed of light. They do get pretty damn close, though. Even so, they carry very little energy and momentum. In most nuclear reactions, the gamma rays carry off much more energy and momentum than any neutrinos involved. So even if you could catch them, they would be of less use than the light for propelling a spacecraft.
>Also, the 'solar sail' phenomenon is based on the fact that the particles of solar wind have mass and thus impart their momentum to the spacecraft.
Not quite. Solar sails use the fact that photons (0 rest mass) have momentum. When a photon hits the sail and is reflected, the craft attached to the sail gains twice the momentum of the photon. The solar wind, on the other hand, is the continuous blast of ionized gas particles ejected from the sun.
Bunsen
Bugrit! Millenium hand and shrimp!
after the whole mix-up, NASA impressed upon everyone to use metric units as much as possible -- that that should always be the default. in a lot of areas it is anyways. according to my boyfriend (the mechanical engineer), the reason why they have to stick with those crazy units is becasue the manufacturing capability of the whole US is geared towards it. it's not exactly a good thing to design a part in metric, convert the numbers, and hand it over to the machine shop.
/crazy/ in metric. while this isn't a huge problem if you don't need a really, really good tolerance, for space stuff it's absolutely necessary.
interestingly enough, this happens in reverse a lot when something in designed in the US and manufactured in other countries -- the engineers are used to imperial, so that's what they use, and the numbers end up being
Lea
Naw, make that:
And all I ask is a tall ship
And a star to steer her past..
a rover I used to work on will apparently be launched in 2003, and there will be other rover flight missions.
this one's HUGE compared to sojourner, and much more capable.
Lea
Oh come on, I can't believe I'm the only person reading /. who actually saw Tron.
I use Macs for work, Linux for education, and Windows for cardplaying.
Fast.
Cheap.
Good.
Pick any two.
The US government has been trying to pick all three and instead has only been picking the first two...
Example. The Galileo spaceprobe is an example of "old" NASA - cost $1.5B, still working now - and doing good science.
The MPL cost what, $150M (i.e. 10% of what Galileo did). And it didn't work.
--
Peter
Oh great. Commentary from someone who says that the UK has a "president." Yutz. I have one forced volunteer for the sail mission.
Podej mi tento talir s koblihama....
All you would need is a big assed roll of duct tape and you could patch that hole in a jiffy. There is nothing that duct tape will not fix.
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Sorry I meant "the power of inertia". Machinery is built with imperial measures, since the tools are imperial, because they build machinery with imperial measures, because...
Et cetera in absurdum.
All opinions are my own - until criticized
It doesn't matter if it's a solar sail, a traditional interplanetary probe, or a space shuttle. If something runs into it, it's pretty much as good as dead. A grain of sand moving at orbital speeds packs enough kinetic energy to do nice amounts of damage to just about anything it runs into.
Mod down posts with a "Free Mac Mini/iPod" sig, they're spam!
For example, Massachusetts was considering renumbering all of the exit ramps on the interstates to coincide with the distances (in miles) from the border (N/S, I don't remember). This would make numbering new exits much easier, as they'd simply follow suit. People protested, saying that they liked the exit number as they were. As a result, we still have exits numbered 21B, 42A, etc. I think we even have a couple C's and D's. Americans just don't like the idea of change very much.
Another reason is that Imperial units were much easier to deal with before computers/calculators than metric. Dividing any number by 10 is easy, metric or Imperial. Just move the decimal place. And to divide by 5, just divide by 10 and double it. But Imeperial units divide evenly by both 2 and 3, a pain with metric. (I know, I know, it's easy to divide by three. But remember, we're nerds. Not everyone could read, let alone divide, when the standard was adopted.)
- Ricky
ERROR READING WARP DRIVE
ABORT, RETRY, FAIL, IGNORE?
Then, there was the solar sail race, to mark the 500th aniversary of Christopher Columbus' voyage. Never got past the planning stage.
If it happens, great. If it doesn't, no big surprise. If NASA spent more of it's ever-diminishing money on doing stuff, rather than talking about it, we'd still have a space program WORTH talking about.
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
There's nothing wrong with NASA, there's something wrong with us. NASA always knew that all it would take to end our ventures into space was a big disaster. In the 80's, we planned on having space stations and colonies BY NOW. What happened? The Challenger exploded, and people learned that there is actually danger associated with all of this, and that there would be losses. Ever since then, NASA has had to walk on eggshells to avoid being destroyed altogether. Privatization isn't because NASA doesn't want to venture out, and doesn't have good engineers. Some of the finest programmers that I know work for NASA. The privatization is because they don't want to be liable, because people have lost their inspiration to learn and to become better more intelligent people. You just have to look around today to see proof of that. If more of our nations finest die for this great cause, then NASA will die with them, because people just don't care anymore.
There's nothing wrong with NASA, there's something wrong with us. That's why private companies are trying to fill their shoes, and that's why you'll see a theme park on the moon before you see a meaningful permanent research colony on Mars.
Eh...
Space is pretty empty. If you stay away from the close vicinty of planets (low Earth orbit, Saturn's or Jupiter's rings, etc.) then you are pretty much safe from anything larger than a very small grain of dust. Presumably the sail is designed to limit the damage done by such grains (like ripstop nylon).
The best trajectory to get benefit from the Sun depends on the level of thrust that can be achieved. If it is high enough to get well beyond solar escape velocity in one perihelion pass close to the Sun then that is the thing to do. A swing by Jupiter may be the way to get that close perihelion pass (Ulysses did something similar).
If not, then you might as well just spiral out from wherever you are, there's nothing to gain by spiralling out from close in.
Steve
I dont see any mention of data aquistition. Is it just going to be carrying the standard picture of people with no clothes, or will it actually have some active components to phone home? I wonder if they could use the sail as a large antenna...
-Yarn - Rio Karma: Excellent
Of course someone will think those numbers are in meters...
All opinions are my own - until criticized
It's nice to see NASA taking the long view of things, but when you consider the alternatives, it seems a little nuts to be considering building a solar sail now or in the next 10 years.
The better alternative would be a magsail, which should be more feasible in 10 years and will weigh less than a ligthsail.
A magsail would consist of a loop of high-temperature superconducting wire. When a charge is run through it, the magnetic field created deflects the solar wind and imparts velocity to the spacecraft.
Downside is, you have to carry a power source. Upside is, with the weight saved in changing from a lightsail to a magsail, this should be negligible. Use a nuclear-thermal battery like in Cassini (about 72 pounds), fire that probe on a close gravity slingshot around the sun, and as it comes around the direction you're aiming for, unfurl the magsail, power that puppy up, and you're *gone*
(Incidentally, these are used in the book "Encounter with Tiber" by John Barnes and Buzz Aldrin. Don't get scared away by the famous name on the cover...it's a great book, and I've been praying that they make a sequel.
blog |
This is the problem with the American public. We want practical results NOW. All we seem to care about is the bottom line, with no room for creativity or imagination. Who cares if the research might be useful extremely valuable to us in years to come. Who cares if it is just really interesting for its own sake? This type of research is needed if we are ever going to explore mars or any of the other planets in our solar system. And why would we want to do that you ask? Why would we even think to spend our tax dollars on useless research into our solar system and planets and comets and asteroids? I don't know about anyone else, but that question is so meaningless to me. I have never even dreamed of NOT pursuing scientific investigation of our universe, simply to KNOW what is out there. if not for the future of exploration or space resource development then to satisfy the desire to know a little bit about where we come from and where we are going. Studying the climate and geologic history of Mars in particular could give us clues into our own future and the results of major climatic change. the desire for "practical" research is fine, but pure research is needed to make the real strides in scientific knowledge that has helped our civilization thrive and clutch its way out of the mud of ignornace that we were born into.
We used this technology to explore our planet over the last 4000 or so years and here are, in our "ultra-modern" lifestyles intending to use the same technolgy to explore the stars. The same stars that they used to navigate those ships by 100's of years ago, and even not that long ago.
This makes me feel like I did when I was a kid. Reading all those sci-fi books and dreaming about the future. I must admit that recently I've gotten a bit "ho-hum" about the whole NASA thing and shuttles and space-stations. I've been thinking that the human race had lost it's exploring drive, with wanting faster computers and our lust for more bandwidth.
But, like I said, I'm a bit of a romantic, and the similarities really apeal to me. Could this be the technology that we use to finally leave this planet and start populating the universe?
Imaging fleets of these things saling out towards distant suns with humans aboard. Establishing space stations around their planets and eventually terraforming its atmoshpere and surface, seeding it with DNA from a planet light years away.
Then again maybe I just read too much of this stuff when I was a kid, but it's still nice to dream about the future.
Who would have thought that NASA has trouble being consistent in their units?
The page on the solar sail craft says "The emphasis of the current research effort is on the interstellar precursor missions designed to set the stage for missions to other star systems later this century."
I'm having trouble deciding whether we're supposed to read this as someone from the 20th century having difficulty learning anything from a 747, or whether NASA is planning on really speeding up the timeline.
Turns out even Europe is based on the Imperial system, at least for somethings.
Where I work, in making airplane panels, the original design came up for about 44 inches from support beam to support beam. So all panels had to be 44 inches from there on out. Of course this is a pain to order, so most companies simply order 48 inch wide panels(that's an even 4 feet for all of the metric people out there), and trim the panel down in house.
The really strange thing is, when European companies order from us, they do give us the spec in metric, but it turns out to be the same 48 inches, and they again trim it down to the size they need.
Yes, it does create a lot of waste, but this is the way things were started back in the beginning of time, and no one has ever bothered to change things, so far as I know. I got all this from a coworker who started sometime in the 50s, and spent the time to ask "Why?", so if I'm wrong, I'm wrong, and please correct me.
..but it never seems to catch on. In high school (8 years ago now) all my math/science classes used metric. Same goes for college. I think most scientific communities use metric now. BUT, the problem comes with everyday use. I am used to seeing MPH on the highway. When I'm going 75mph I know I'm speeding. When you say 75kph, I have no freaking clue unless I think about it. 60C? What the heck is that?? I know 60F is a cool day in a second. People don't want to think about these things - they want to see a number and know what it means instantly. So maybe your "inertia" idea is a good one too. At my college, the cafeteria is called "SAGA". The Saga food service company hasnt been there for 10 years, but every freshman class learns to call it SAGA from the upperclassmen. They tried to force us to stop (Mariott was the company that didnt like us calling them that) but how can you?? hehe, I'm rambling now, but you get the idea :)
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"Every artist is a cannibal, every poet is a thief."
Since in relativity momentum and energy are related through the equation E^2 = p^2*c^2 + m^2*c^4, for a massless photon there is a relation between its energy and it's momentum p = E/c, so light falling on the solar sail has a momentum and thus exerts a force on it, pushing it away from the direction the light came from.
I can't remember any more at the moment, it's been a while since I studied thermodynamics at university :)
So we can conclude that NASA's century/millenium rollover occurs 2000/2001.
Boy, am I in a sarcastic mode today?
All opinions are my own - until criticized
And all I ask is a tall ship
And a star to steer her by..
This is all well and fine for unmanned probes, but what if they wanted to put people on it? How would they have the energy to return? Would they have to aim towards another star so they could turn around? (They'd have to first worry about slowing down; even if it's thin, it would be fairly massive with a crew compartment, and at 58 mi/sec that's quite a bit of momentum.)
Gates' Law: Every 18 months, the speed of software halves.
...and so more likely to be noticed by any passing interstellar tourists. Maybe NASA could arrange for additional funds through selling advertising space on the sail? ;)