Beaming into Space 124
HobbySpacer writes "At this week's 1st Int. Symposium on Beamed Energy Propulsion in Huntsville a wide range of laser and microwave propulsion schemes are being presented. The big news so far is the announcement by Gregory
Benford of plans for a test of microwave propulsion with the Cosmos Sail, due to fly early next year. The possibilities of using lasers to deflect incoming asteroids & comets are also under discussion."
They should get in contact with Junis (Score:2, Funny)
Re:They should get in contact with Junis (Score:1)
Not creative enough (Score:5, Funny)
Microwave propulsion systems? (Score:5, Funny)
Ding!
so the only thing holding us back (Score:1)
Do we click stop to ignite?
Re:Microwave propulsion systems? (Score:1)
Re:Microwave propulsion systems? (Score:1)
brrrddm..tish!
Re:Microwave propulsion systems? (Score:2)
Re:Microwave propulsion systems? (Score:1)
0 ???
-1 Profit!
*ducks* =)
Why deflect Asteroids? (Score:4, Funny)
Re:Why deflect Asteroids? (Score:2)
Or was that the trees?
Re:Why deflect Asteroids? (Score:3, Funny)
Re:Why deflect Asteroids? (Score:1)
Re:Why deflect Asteroids? (Score:4, Interesting)
Re:quotable quote (Score:1)
Most immediate space challenge? Riiight.... (Score:4, Insightful)
Wow. I always thought that the likelihood of an asteroid hitting Earth was low, at least low enough that ther are probably better things to spend one's time addressing... say, hunger, AIDS, yadda yadda yadda.
A larger problem is how to lower the cost of missions to allow for an increase their frequency. If this kind of technology c(w)ould be used to allow humans or unmanned craft more time in space to collect data, I think that would be far more useful.
The quote smacks of FUDing. Oooh, look out! A big bad asteroid could it us! You all saw "Deep Impact", right? Well, better fund us so we can make sure that never happens...
Re:Most immediate space challenge? Riiight.... (Score:2, Funny)
Give them a break..... (Score:5, Insightful)
I think you are being way to skeptical here .
Look, you can say all you want but you are talking about something which can basically wipe us. Not to be a controversialist but wherein AIDS and hunger if you aren't there in the first place. Yes, I agree maybe its not top priority as much as the folks quote but its bloody well important. You think even if we spot an asteroid we can do anything about it.....throw a few nukes doesnt solve it. Want us to be sitting ducks and pray ? Maybe you should take a look again about Schu-Levy?
Also how many times will the AIDS+hunger thing come up ? If your view is right then we should stop all technological innovation and start feeding everyone. It doesn't work that way - we should try to fight AIDS, hunger but at the same time its _very_ important to look forward
No offence. Thanks,
vv
Re:Give them a break..... (Score:3, Insightful)
Wouldnt happen 400 years from now when we have uber-laser blaster hyper 500-k warp missle blaster thingies, would it!
Re:Most immediate space challenge? Riiight.... (Score:5, Insightful)
You're talking about different areas of science here. Scientists aren't exactly being pulled off AIDS research to work on this problem. However, a tragic asteroid impact would mean that AIDS and world hunger wouldn't be on everybody's top lists.
Re:Most immediate space challenge? Riiight.... (Score:2)
Everytime I see Lou Dobbs on Cnn, I think of space.com. It always gives me a good chuckle..
Re:Most immediate space challenge? Riiight.... (Score:1, Redundant)
Wow you're right,hunger AIDS "yadda, yadda", are more important space challenges
Re:Most immediate space challenge? Riiight.... (Score:1)
But, a good size asteroid can wipe out the planet. Literally.
And the larger the asteroid, the further out that we have to act.
Re:Most immediate space challenge? Riiight.... (Score:3, Insightful)
Yes, it is rare. Yes, we should worry about other, more common problems. The only thing is that with our other problems, even if they become epidemic, they are not likely to ever wipe out the entire human race. One big collision with an asteroid, however unlikely, can easily end the human race (along with many other types of life on this planet).
Even though a calamity such as a large impact is extremely unlikely on the scale of our lifetimes it is almost inevitable over the course of thousands or millions of years. Another big collision could happen tomorrow and there would be nothing we could do to stop it. I for one won't feel totally safe until we have a decent amount of our planet's life on another planet or space station.
Sure let's keep improving as a race and continue our efforts to make life better on Earth, but let's not forget the fact that we really are living on borrowed time until we can deflect those threats from space which could destroy us in a flash.
I'd like to know how long AIDS will take (Score:1)
(given its current trend)
and
(assuming
((the absence of a 'miracle cure')
and
(that the number of humans with natural immunity would put us at the very pinnacle of the endangered species list at the very end)))
Might it be possible to calculate roughly how long we have as a species?
And I also don't want any lisp jokes I was just trying to be clear and its not syntactically correct anyway.
Re:I'd like to know how long AIDS will take (Score:2)
The spreading of AIDs is dependent on behavior, so the answer to your question varies with the predicted behavior of the population. Plus, as AIDs spreads, it will change the behavior of people who are impacted by it, altering the rates of infection. So, using the current trend to predict the extermination of the entire human race is extremely unrealistic. If AIDs infection reached the unlikely level of, let's say, 20% of the worlds population, most of the rest of the population would be very motivated to avoid activities that would get them infected.
Re:I'd like to know how long AIDS will take (Score:1)
Look at the impending ecological disasters; people *only* change their behavior when things get so bad that either they change or they sink into cognitive dissonance and start hallucinating.
At that point, its usually past the point of no return.
I'd still like to know what the projection would be, assuming that people *don't* modify their behavior.
I'm sort of gesticulating at the 'we should research stopping AIDS before researching stopping asteroid impacts' thread; which is genuinely the greater threat?
Which of them, if left unchecked, will likely exterminate us sooner?
Re:I'd like to know how long AIDS will take (Score:1)
It's more likely that a few million survivors would be scattered across the globe, retreating into small communities. Those that didn't starve because they don't remember how to farm would face a future of genetic impurity and inbreeding.
Even a 50% reduction in the earths population could wipe out the race.... it might take a bit longer, and involve some paranoid countries throwing nukes around, but in the end, the same would happen.
In answer to the grandparent, I vaguely recall from years ago a report that said even though many second and third world countries would be wiped out, the G8 would likely survive, and keep it's children safe in hospitals long enough to find a cure. The report concluded that AIDS could not exterminate the race entirely, only thin the population and decimate underdeveloped countries that couldn't afford to keep children isolated.
Probabilities (Score:3, Insightful)
The reason for that is that floods and earthquares are local and therefore you can hear about them happining somewhere else and perceive them as a threat. When an asteroids hits Earth there will be no "somewhere else".
Re:Most immediate space challenge? Riiight.... (Score:2, Insightful)
That very well may be, but as you yourself have pointed out in the subject, asteroids are the most immediate space threat. As opposed to AIDS, hunger and yadda yaddas (although yaddas may turn out to be of extraterrestrial origin
Besides, it is low probability, but as we will surely get hit by an asteroid sooner or later, the more time passes, the more probable it becomes. And the consequences of an asteroid hit (immediate devastation and secondary fallout, not excluding a new ice age) definitely warrant at least devising a game plan, if not immediately acting on it.
Remember, it's not a question of 'if', it's a question of 'when'.
One thing to not worry about. (Score:5, Funny)
The inflight meal will not be cold.
Re:One thing to not worry about. (Score:3, Funny)
A simple proposal (Score:5, Funny)
2) Don't let them out until they have a prototype design for FTL.
Physics has become boring and I think we, as a species, have to put our collective foot down as regards this whole no FTL business. You can worry about whether or not black holes emit radiation later, I want a warp drive and I want one yesterday!
Re:A simple proposal (Score:5, Interesting)
Start with a space elevator, price tag 10 - 40 Billion dollars. Then maybe build a *NICE* space station on top of it, which should cost much less. Use the space station to build a spaceship for the purpose of bringing an insanely mineral rich asteroid back to Earth orbit. Establish a mining base on the asteroid.
3. Profit.
Tim
Re:A simple proposal (Score:4, Informative)
More info here:
http://science.nasa.gov/headlines/y2000/as
Re:A simple proposal (Score:1)
Really, we don't have the technology yet and won't for at least 10 years. Carbon nanotube technology is still in its infancy.
Re:A simple proposal (Score:2)
A skyhook/space elevator is a good idea for science and space travel etc. However, if you had one of these, the best way to make money off of it would not be by importing asteroids, remember, conservation of angular momentum would mean that getting asteroids to earth probably requires more energy than mining minerals on earth and sending them up the elevator...
No, if you wanted to make money or, at least get closer to breaking even, you would need space tourism. Having a hotel in space would generate revenue, and you have a large body of people who would want to stay in the hotel for a week or so. Look how many millionaires try to get to the space station.
The other way you could "profit" from this would, again be bringing asteroids in from a large distance, but not slowing them down, rather using them as weapons in a war. Not nice, and not exactly "profit" but it would be a non-nuclear weapon that could certanly turn the tide in a war. And, if you are the victor in a war, you generally profit. (Generally...)
Re:A simple proposal (Score:2)
Re:A simple proposal (Score:2)
No alien, (Score:1)
in their RIGHT FLAMING MIND would
let us pull something like that off.
Next thing we'd be among the stars
destroying ecosystems left right and
center.
I mean, look how we treat this one,
and its the only frikking one we've got!
In fact if I were an alien, which to the best of my knowledge I'm not, I'd put a flaming FENCE up!
Re:A simple proposal (Score:2, Interesting)
1. Wait a few decades for exponential progress to give birth to nanotech. :) :)
2. Cheaply launch my very own tiny "seed" factory towards a suitable asteroid, where it sets up shop awaiting my specific matter transformation instructions, and defends against "molecular thieves" who might want to jump MY asteroid claim.
3. Wait a few more years along the exponential tech curve for "mind uploading" to evolve.
4. Broadcast my "neural blueprint" (with ECC!) off the eggbasket (Earth) to my new asteroid-sized brain; grow and reconfigure to fill available space.
5. Join up with the rest of posthumanity in the newly forming Matrioshka Brain [aeiveos.com]
6. Ponder 42.
7. Simulate new universes for fun... like this one.
8. Profit doesn't matter here.
--
Be Careful What You Wish For (Score:2)
Be careful what you wish for. Thanks to fun things such as String Theory [superstringtheory.com], Time [a-city.de] Dilation [aci.mta.ca], and Quantum Time [colorado.edu] Travel [susx.ac.uk] you just might get that warp drive... yesterday!
how many nuculear plants does it take... (Score:1)
Exactly how many Nuclear power plants would it take to deflect a meteor that's of any real global harm?
I think I'll take the meteor myself...
Re:how many nuculear plants does it take... (Score:2)
One
Upgrades on the Pickering powerplant are about to be abandoned
It looks like 'reaction mass' is one possibility for it's highest and best use.
We just have to get it in orbit and transport it to the asteroid.
There is a limited demographic that will get this joke.
Re:how many nuculear plants does it take... (Score:1)
FTL Here we come (Score:1)
Or a Soffa (Score:2)
That, or a chesterfield will keep appearing, zipping around, and disappearing on my front lawn driving me nuts - before finally appearing in the middle of Lord's Stadium just as the cricket match is getting, err, "interesting"! Bloody eddies in the timespace continuum.
Great a propulsion system that flashes 12:00 (Score:5, Funny)
Asteroid Deflection (Score:1)
I cant see lasers helping all that much.
Re:Asteroid Deflection how? (Score:1)
Re:Asteroid Deflection how? (Score:2, Informative)
Re:Asteroid Deflection how? Thank you (Score:1)
Re:Asteroid Deflection how? (Score:2, Informative)
Simple. The "reaction with the atmosphere" is that the air is so strongly heated by the beam that it ionizes, expands, and shoots out the bottom of the projectile. Turn off the beam. Wait for the ionized air to get out of the way. Repeat tens or hundreds of times per second.
The asteroid deflection plan would work much the same way. Very high energy pulsed beams would vaporize some of the asteroid material from one side of the rock. That jets off into space, creating a small amount of thrust. Keep the beam on the asteroid until it has enough velocity to miss us.
(Delivering that much energy accurately to the target over astronomical distances is left as an exercise for the student. ;^)
Re:Asteroid Deflection (Score:3, Interesting)
So i did not RTFA. However to "deflect incoming asteroids & comets" with
photons is ridiculous idea. Photons carry momentum h*nu/c and
energy h*nu. One way to treat the problem is to consider a simple mechanical
collision of photon and target (asteroid). I did a "back of an envelope calculation"
and derived a following results:
For the visible photons of 550 nm, a beam of 1 GW produces a force of 6.7 N (~ 1.5 lb).
Now that is really going to take care of that 1 000 000 t asteroid.
Now let's try another approach. Let's assume that the said 1 GW beam vaporizes surface of
the asteroid and that "rocket effect" has 100% efficiency. 1 GW applied on the
1 000 000 t body for the duration of say 86400 s (1 day), changes the body's velocity
for 415 m/s. This is much better, particularly if the target is irradiated far away from the
Earth. However, with the current technology it is feasible as much as the "tractor beam".
Re:Asteroid Deflection (Score:1)
Re:Asteroid Deflection (Score:2, Funny)
Silly Human!
Tractor beams would only help if we could get behind the asteroid and "tug" on it. This application clearly calls for a Repulsor beam!
Just how much? (Score:4, Funny)
Is there enough momentum in that laser to actually change the velocity of a flying windows license appreciably enough to make it miss (assuming it's on a collision course - after all - it might blue-screen before it hits Earth and stop say, 62 miles from impact).
The only thing this laser deflection system might buy us is instead of being annihilated by a really fast, frozen rock from outer space, we're annihilated by a piping hot rock from outer space that turns the Atlantic Ocean into a giant thingie of Jiffy-Pop before we all are vaporized, or have our guts ripped out.
Funny how energy expended always seems to come back and bite us in the proverbial arse... How many more movie references can I cram into this post?
Re:Just how much? (Score:2, Informative)
Look just above your post. It shows that the vapourized asteroid is the factor, not the "momentum" of photons from a laser.
We need ChiaEarth! (Score:4, Funny)
We just build another Earth out of paper mache and move to it before the asteroid hits.
Re:We need ChiaEarth! (Score:2, Funny)
Re:We need ChiaEarth! (Score:2)
"Beam me up...." (Score:3, Funny)
Re:"Beam me up...." (Score:1)
My thought exactly.
Actually, the headline conjured up an image of two Kazons floating dead in space in one of the early ST: Voyager episodes.
Mmmm asteroid (Score:4, Funny)
Bacon: 20 minutes
Asteriod: 5 hours on high, serves 10-15
-jokerghost
Re:Mmmm asteroid (Score:3, Funny)
alumnized mylar? (Score:2)
Re:alumnized mylar? (Score:2)
Well, that just means that the sail will spark madly.
solar sails? (Score:1)
</cheeseypun>
They're talking about solar-sails, but...is there
any mention of how big their proposed solar-sails
will be? I seem to remember that those things have to be frikkin' huge...and I never knew you could propel them with microwave radiation...I though you needed a huge frikkin' laser-cannon for that.
(Yes, I've been reading too much -old- SF
Oh wait...should've read more carefully...they WILL use laser-cannons. Neat, another excuse for the American Government to spend millions on huge orbital laser cannons.
How fast can/will a solar-sail propelled space-ship go? Can I start booking a trip to Mars anytime soon? How long will the trip take?
I'll bring my cell-phone, with all the radiation
that thing puts out we'll be there in half time
Best quote:
--
"Because 'concentrated' energy is hard to come by in space," said Jordin Kare of Kare Technical Consulting in San Ramon, California.
--
Uh...hello? Solar panels? Solar power? Near unlimited power? What am I missing here?
Since my NickName is DarkHelmet. (Score:2)
Oh yes, Scotty Beamed me Twice last night... it was wonderful..
Re:Since my NickName is DarkHelmet. (Score:1)
Since my NickName is DarkHelmet
small nitpick: that was president scrooge.
sorry, couldn't resist it
Well, there you go. (Score:1)
deflect this? (Score:2)
Microwave Beams: Phased Array Antenna (Score:5, Insightful)
lasers, is that is really easy to make a stearable
beam of Microwaves using the phased array technique. I you make a dipole antenna and feed a
microwave single into it, the signal goes pretty much everywhere, if you put another dipole antenna, next to the first, the two signal interfere results in a more direction beam. If you
have a square grid of antennas, you get a narrow
beam which becomes more focused as the density of
the grid increases.
If all the signals are in phase then the beam goes straight ahead (also straight behind, so you put a microwave mirror, a metal plate behind the antennas at a (half) integer number of wavelength in distances.
To stear the beam, you just put a slight phase difference between each dipole antenna and the ones next to it, so that the phase difference increases with the distance between the each dipole antenna and the first one, thus the beam is stearable electronically. Because there a lots a seperate dipole antenna, the power in each does need to be to large, so you can use fairly ordinary electronic components to produce the beam.
Imagine, building a simple block of antenna, consisting of a 100 by 100 dipole antenna, each
feed by its own 100W oscillator, and with its own
control and stearing computer inside. That should
be fairly cheap to build. Now mass produce these.
Now lets put a hundred of these side by side in a square, you
get a stearable 100 MegaWatt beam and its only 10meter by 10meters big.
You can use this idea to build with conventional
technology a microwave beam as powerful as you like.
Now you don't get much thrust from just reflecting
the energy, 6.7 Newtons per gigawatt. But a constant accelation over time can quickly build up speed in space. You can get a lot more thrust out of the system by using the microwaves to heat a reaction mass, say water in the target craft. I haven't done the calculations, put a powerful enough beam could be used to launch a steam rocket from the earths surface at very little cost.
Not a good idea (Score:3, Insightful)
Masers are coherent and therefore capable of creating an extremely narrow beam with virtually no side lobes. New technologies for masers bring their efficiency from the low single digits to around 50%.
Re:Microwave Beams: Phased Array Antenna (Score:1)
Asteroids (Score:3, Funny)
Scientist: Ok *pointing to a screen* here is a little demonstation of our ship, and if you notice the propulsion system here the ship will accelerate very quickly. And here's a shot of it shooting asteroids with the high powered laser, we are guessing the asteroids will break up when shot so we will make sure the laser can quickly destroy any little asteroids as you can see here. Any questions? Ah you in the back *pointing to a reporter*
Reporter: Yes, well I have one question, isn't that just the game asteroids for atari?
Scientist: NO FURTHER QUESTIONS *storms out quickly*
Microwave propulsion (Score:2)
Re:Microwave propulsion (Score:4, Insightful)
Re:Microwave propulsion (Score:1)
Or, transition the crew's diet to Microwaveable Bean Burritos...err, sorry, maybe that's what you meant.
Asteroids (Score:1, Funny)
Meteor to Earth. (Score:1)
Aaaaahhh, STOP doing that, I hate kids who play with LaserPens!!!!!!
Preparations... (Score:1)
Preparation H!
Intelligent Combination (Score:1)