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Nuclear Fuel For Superfast Interplanetary Travel
jdoire writes: "Using a thin metallic film of americium-242m, a rocket could reach Mars in only 2 weeks. This is made possible because the nuclear material could be used both as a source of energy and as a propellent material, making the engine very efficient and light weigth. Check ScienceDaily for the full story."
The article is slashdotted, but from the Slashdot description, it sounds like we're talking about a radioactive substance that would be expelled for a reaction force. Is that right? If so, then it sounds like you don't want to be anywhere near or downwind of the smoke cloud this thing makes when it takes off.
I hope I'm misinterpreting this, because my first reaction is: "Gee, that's stupid." I mean, it doesn't sound as bad as Orion, but still...
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The properly attributed text is thus:
LISTER: What do you believe in, then? Do you believe in God?
RIMMER: God? Certainly not! What a preposterous thought! I believe in aliens, Lister.
LISTER: Oh, right, fine. Something sensible at last.
RIMMER: Aliens, Lister, with technology so far in advance of our own we can't even begin to imagine.
LISTER: Well, that's not difficult. Mankind hasn't even got the technology to create a toupee that doesn't get big laughs.
(Red Dwarf Scripts are here )
"When it rains, it pours." --Morton's Salt
...and I know for a fact that both Project Helios and Project Orion were not intended for use inside the atmosphere of Earth.
Some early incarnations of Orion actually did call for launch inside Earth's atmosphere. At the time it seemed (and still seems) the cheapest way to develop "very heavy launch" capability quickly. While there is still a fallout issue, one can envision scenarios where people would trade fallout for unpleasant consequences--e.g., to get equipment into space in order to prevent Earth's colliding with a large meteor.
naw, I'll just buy solar cells for the roof of my house. - stock options - mmmmmmm. THEN I'll gladly accept "market prices" for electricity. When the power company has to buy my surplus!
Screw you PG&E.
These are my friends, See how they glisten. See this one shine, how he smiles in the light.
> I guess space travel has come a long way since I went to sleep last night!
Timothy Leary pioneered interplanar travel back in the '60s. NASA just now found a legal way to do it.
--
Sheesh, evil *and* a jerk. -- Jade
Small half-life means highly radioactive. That's why you can hold a piece of uranium-238 in your hand (half life 4 billion years), but I would not recommend holding a piece of say Cobalt-60 (halflife 5 years).
Yes, the length of an efficient Hohmann orbit is a lot greater than the straight line distance to Mars. But with a travel time of two weeks, efficiency goes completely out the window; you would be practically taking a straight line path.
.1 G.
.15 G figure is probably more accurate, and even a wide margin of error wouldn't change the answer to the "would I be pureed by this acceleration?" question.
Calculating the actual orbit is a non-trivial task, but I recall that for the outer planets, at least, the straight line approximation mghiggins did wouldn't be very far off (in terms of relating travel time and acceleration) for a constant-thrust ship of even
Also, I'd assume "trip to Mars in 2 weeks" means when Earth is passing closest to Mars in it's orbit, so the
heh... yep... See what happens kiddies, when you don't have your regular intake of sugar and caffeine. You miss all kinds of things. The above figure of 16000 km./hr. should be 16000 km./min. The actual figure for hourly travel is now 960,000 km./hr.
And now back to our regular program...
Eric Gearman
--
Atomic batteries to power! Turbines to speed!
Quoted from 'Gee-Whiz Facts about Voyager
A groovy little slide show from the Netherlands about space radiation.
Space Radiation and it's effects
Capt. Ron
crazy dynamite monkey
I want to see us go to Mars, but I don't want us to rush it. I am sure that you have taken note to the backlash that NASA took when it lost several probes in a row. Those were unmanned and they got reamed big time. Imagine what the public would do if NASA lost six astronouts while enroute to or on Mars. Chances are good that NASA would either get axed or be so horribly crippled from budget cuts that it might as well be dead. Although the technology we have currently is capable of sending manned missions to Mars, we need to do more research and more testing and patience before we can achieve a SAFE mission to Mars. I am sure we will get there, and within my lifetime. Why, because it is one of NASA's priorities. Right now they are spending most of their budget on the ISS, as you know, which IS necessary. I personally believe that having a working space station is as necessary as sending someone to another planet. Once they are done with the ISS then they can move onto providing more time and funding to the Mars project.
Disclamer - Opinion of Person
Mouse. You're missing a 'karma' from your sig.
:-)
> > At 150,000 mph, we're traveling approxiately 2,500 miles per second.
> Math isn't your strong suite, is it?
It's OK, he works for NASA.
--
Sheesh, evil *and* a jerk. -- Jade
Interesting point (speed = 0.014 x c). Time & mass dialation could be measureable, but it's still not enough for serious issues to occur. The wierd/cool stuff doesn't appreciably happen (IIRC) until about 90% of c.
Can we get a "-1 Wrong" moderation option?
Mars Direct isn't nearly as ephemeral a plan as the Apollo missions were (the Apollo missions didn't leave automated fuel production facilities and human habitats on the moon, for instance) but I expect the end result would be the same: a half dozen missions, followed by nothing.
If you want to see real exploration of space, the way to do it isn't to throw a few men to Mars, damn the cost; the way to do it is to reduce the cost!
That reminds me of the time that an overzealous newspaper editor in Washington (I can't recall which of the papers it was) blindly changed the text of a business report to read that the market was expected to soon be "in the African-American".
Information wants to be anthropomorphized.
Youessicium ?
The Web is like Usenet, but
the elephants are untrained.
Some high school kid was collecting smoke detectors in his back yard and scraping out the Americium for some project. Turned into a royal mess for Hazmat/ABC personnel to clean up.
Can we get a "-1 Wrong" moderation option?
I think they would used standard solid fuel boosters to get the 2nd and 3rd stages (also solid fuel propellant) into space and after the payload has made it out of "range" (?) of our atmosphere the 'high-speed' engines would kick in.
Capt. Ron
crazy dynamite monkey
Using this technology, I should be able to make it to work in about 0.2 seconds!
-S
--- What parts of "shall make no law", "shall not be infringed", and "shall not be violated" don't you understand?
Getting americium isn't that impossible, but it is dificult. The steel and metals industry uses americium to gauge the thickness of metals.
In fact the company I work for now probably has a few pellets from many years ago. I don't think they are of this isotope, but still, it can be found.
Oh, BTW, if it wasn't mentioned, the half life of Americium-242 is about 16 hours. It's relatively easy on the environment. However, Am-241 has a half life of 432 years. And to make matters worse, Am-243, the most stable isotope has a half-life of 7300 years.
Didn't I read somewhere that they gave them suicide pills for just such an event. I know I'd take the easy way out rather than suffocate. Nasty way to go...
The solar wind will blow the fission product gasses out of the solar system once the probe is far enough from the earth. As far as breathing it if the engine was started near the earth: the diffusion through the atmosphere would likely reduce the radiation emitted by the fission products significantly (just like how in a commercial nuclear power plant the fuel assemblies are placed in a water tank until the fission products that were created in life decay to a reasonable amount). Its highly unlikely that even a fleet of these spacecraft would have any impact that could be observed. This is a viable technology and should be studied and deployed if it works.
Suddenly, the hairy finger of a familiar monkey tapped me on the shoulder. It was time.--G. T.
Just an addition: What I meant by being far enough from the earth is that it would be past the magnetosphere (where any interplanetary probe will have to go anyways) so that the solar wind could have an effect, because the earth is shielded from the solar wind within the magnetosphere.
Suddenly, the hairy finger of a familiar monkey tapped me on the shoulder. It was time.--G. T.
PG&E still owns Diablo Canyon (my backyard), and they only JUST finished a refueling, they were down for a few months before that, for refueling, not "repairs".
These are my friends, See how they glisten. See this one shine, how he smiles in the light.
Yeah, I sure would like to know more about DU in weapons tech. - if you feel like posting more about it, you've got my vote.
I am familar, however, with some of the basics - uranium is primarially an Alpha ray emitter. These are basically harmless - a sheet of paper can stop them. Of course, decay can produce Beta and Gamma radiation. The fact that the "real" danger from, as you rightly point out, depleted uranium only arises when you're talking about inhalation of dust-like particles (for whatever that 'fact' means- according to the media today and yesterday in Ireland, Britain and France the 'facts' about DU seemed to change from station-to-station hour-to-hour) has not escaped me.
The thing that I find deplorable -if true- is the way that such matter can effectively and easily poison a water/food supply. I assume this could happen because of the radioactivity of the matter produced by a DU weapon's strike. However, details were sketchy on the TV reports.
I've looked up the subject of DU on the internet - again lots of controversy but with the anti-DU voice being the loudest.
Try http://www.iacenter.org/depleted/du.htm. I must state, I am very wary of a site like iacenter.org, but sites such as this (http://www.rama-usa.org/ducdi.htm) hold much more sway as they seem less politically motivated. Another site, this time an American veteran's, is here, and a very comprehensive site is here.
For my money, the better site is http://www.psr.org/duissuebrief.html.
Mind you, just to add my voice to the mass of anecdotal evidence out there: I've been around a variety of dangerous chemicals and elements. I've had fun with everything from quick silver(liquid mercury to the modern man) to a variety of radioactive isotopes(calm down- it was within the confines of a university 8). I am well aware that there is unecessary panic by those without a good knowledge of the related chemistry and/or physics. However, I am still very uneasy about certain things I have had direct contact and just because I've experienced no side-effects, it doesn't mean everyone else will escape side-affects after sharing the same experience as myself.
8)
Concrete analysis...
(ahem) "doing the math", one week of 1G constant acceleration will get you 182,891,520,000 km (or about 30 thousand times further than pluto!) My math may be off (:!) but you get the idea! (and yes, this may not indclude decerlartion... but still! Anyone who is math-enabled, please have at it!)
Oliver's Law: Experience is something you don't get until just after you need it.
Personally, I can't wait until man makes his first interplanar voyage. Just think of the important discoveries to be made on other surfaces!
This article is available elsewhere on slashdot... Argle... So I'll repost my comment again too...
Okay - it's based on values dependant on acquiring reasonable quantities of Am... But, what I read into this, is that an application of using another radioactive material in a different alignment/form could generate the power necessary for this short of a trip.
It's almost sounding like more and more like the early attempts at getting controlled fission to work with differing opinions on the actual arrangement of the fuel. They tired different methods, and finally arrived at what they needed.
I wonder if the explosion of distributed computing for medicine could also be applied to configuring radioactive material alignments and shielding to improve reactors?
Drat - I only get 3 weeks vacation a year so Mars is out - I guess I'll have to settle for the Dominican Republic again...
I donate all spillover Karma to the charity of my choice... Ada was still a babe despite what people may say...
2 weeks to get to mars means you're moving at an awfully good clip. i wonder how big a crater a ship moving that fast would leave - if we send up a couple of those i bet we could add ears or dimples to the face formation on mars...
True, ive thought about this before, also what about using water for acceleration purposes? couldnt they stand a far higher G if they were immersed in water or a gelatin? How solid would you have to be to survive electromagnetic acceleration?
I was also reading about how they were extracting dinosaur dna (i know its trite) by looking at carmelized feces and then reversing the chemical process to break out larger bits of dna. Apparently the carmelization process acts as a scaffold or structure to hold the dna together. Sounds very starwars 'carbonite'-ish but has there been any research in the area of locking cellular structure in a crystalized shape? I suppose they could put together a seti@home style algorithm to look for suitable chemicals.
http://www.livejournal.com/users/cixel
IMO,
why should a waitress who marries Bill Gates get millions in alimony if they later divorce? Or any of the assets that Bill owned wholly before their maiirage?
she should get $250 for an hour, like all the rest. (Extra $100 for "greek treatment")
These are my friends, See how they glisten. See this one shine, how he smiles in the light.
penis butt juice
www.droppingdimes.com
It's most common decay mode is gamma radiation, so I don't know how useful it would be for fission, but the only other Am242 nuclides are the one with the aforementioned 16-hour half-life and one with a half-life of 14 ms, so I figure this must be it.
Consult the nuclear physicist in your family for more details.
OK,
- B
--
http://www.bradheintz.com/
- updated
Agreed - we can all live to these standards quite comfortably if there werent so many of us! I plan on having only 1 child to 'do my part' -- and I am very actively thinking of having none...
running out of air, freezing to death, radiation, every astronaut since Yuri Gagarin was prepared for these potential fates.
It's called being a hero. Knowing you're expendible is one thing. But knowing that it was for a cause as high as space exploration (imo, there are few higher), makes it worthwhile. Remember the proposal a couple of years ago, at a space-science conference, where a scientist said that if a Mars trip were one-way for the astronaut, it would make the whole project cost about 1/3, and who would volunteer for such a mission - go to Mars, but certain death? Every person in the audience raised their hand.
These are my friends, See how they glisten. See this one shine, how he smiles in the light.
Take a look at the plant in Morrow Bay, I think that is owned by Duke energy but has not been turned on in years, although it's good and ready to go. I think they can't turn it on due to "environmental reasons." The most interesting thing to note is that while the Electric Utilities are having cash problems, the companies that own the plants are making money hand over fist!
Also PG&E owns Diablo Canyon if memory serves me correct. My friend's dad is a Nuclear Welder, doesn't talk much about Diablo canyon except to say that when you see a pink stop sign, you know you're in the nuke areas....
---- Fight to protect your right to keep and arm bears! ummmm... ya I think that's right....
> A sodacan sized Americium nuke can open the barricaded door in seconds, and allow heavily armored policemen inside, while the pipe is still being inhaled.
Or at the very least, you'll have silhouettes of the victims^w criminals burned into the walls, revealing exactly what they were up to when the can popped.
--
Sheesh, evil *and* a jerk. -- Jade
The excessive Gs come from speeding up and slowing down.. half the trip you would be accelerating, the other half decellerating. We can travel at any speed and it will feel like we are just standing still. Its the acceleration/deceleration that gets ya :)
Luke
> What good is it to have tiny nukes if we have no ability to deliver them to other planets, where hostile alien races are sure to be setting up a similar attack on us?
It shouldn't take a new Solomon to figure this one out. Look at the names. Clearly, Americium was made for use in America, and Neptunium was made for use on Neptune. So use the one for nukes, and the other for spaceships.
--
Sheesh, evil *and* a jerk. -- Jade
min: 54,500,000 km (~ 34,000,000 mi)
avg: 78,000,000 km (~ 48,750,000 mi)
max: 401,000,000 km (~250,625,000 mi)
Assuming the 2-week estimate is based on the minimum distance this means that it would take 336 hours to travel the 54,500,000 km for an average speed of about 45,000 m/s. If the acceleration of the ship could be held constant at 10 m/s^2 this means that a near Earth gravity effect could be achieved for about 75 minutes at the begining and the end of the trip. A near Mars gravity effect (3.7 m/s^2) could be maintained for over 3 hours on each end of the trip.
In order to maintain an Earth like gravity for the entire trip the ship would need to attain the speed of 740,000 m/s (accelerate at 10 m/s^2 half way out and then flip the ship around and decelerate at 10 m/s^2 the rest of the way). In order to maintain a Mars like gravity for the entire trip the ship would need to attain the speed of 450,000 m/s (accelerate at 3.7 m/s^2 half way out and then flip the ship around and decelerate at 3.7 m/s^2 the rest of the way).
Of course either 450,000 m/s or 740,000 m/s would give us measurable time/space/mass dilation problems. So you gain a little weight you get a little smaller and you age a littler slower -- basicly you would be young, short, heavy and hauling ass!!!
I know this planet that has this stuff that when taken in vast quantities allows the user to fold space allowing for instantaneous interplanetary travel.
This is not the way to build a lasting empire.
Wanna have fun? Figure the time to Pluto using the same stuff. (It's in the book, look it up.)
No joke. I'm busy collecting a large number of smoke detectors as we speak in the hopes that I'll be able to make the quick trip to Mars within my lifetime.
;-)
Stating on Slashdot that I like cheese since 1997.
I'm sure some group will protest. "It might poison our atmosphere".
<toungue location="cheek">
--I can think of a *lot* of government organizations that I wish would go to mars.
</tongue>
The Web is like Usenet, but
the elephants are untrained.
I hate to admit it, but it looks like this is one dirty idea. They plan to use fision products as propellent! That is nasty, much worse than NERVA, even Orion. If they manage this it might be to dirty to use in the air.
Friends don't help friends install M$ junk.
On a side note, NASA knows that its people are worth far more in training and experience terms than the money it costs to pull off a rescue attempt, regardless of the complexity.
Evan - needs to hit preview before submitting
Wow... I guess space travel has come a long way since I went to sleep last night!
--
SecretAsianMan (54.5% Slashdot pure)
Washington, DC: It's like Hollywood for ugly people.
Since my original post was modded down, this confirms that Slashdot effectively IS the site for editors who cannot spell.
Sigged!
I do.
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Math isn't your strong suite, is it?
150,000mph / 60 = 2500 mp minute
2500 mpm / 60 = 41.66 mps
BTW - that 150,000 mph figure - is that supposed to be peak velocity, or something else?
So, what's that, Earth to Mars In Two Weeks?
That's a pretty good posting Hemos, but what department is it from? Hemos: "The" department.
... and we STILL can't create a toupee that doesn't get big laughs.
Ceci n'est pas une sig.
Yes, I agree conservation is a crucial goal. But it's not enough. First off, the government shouldn't be running around decreeing what is "useless disposable crap" and what isn't. Let consumers decide by exercising the vast power their pocketbooks. Or if DickBlonalds Crappy Smeal toys are costing an inordinate amount of power to produce, fine, pass the cost of the power on to the company, which will in turn have to pass it on to consumers, who will maybe decide they don't need the things so much after all. Secondly, California's population and economy is continuing to grow rapidly, and power plants take time to build. So even if conservation measures were to cut energy use significantly, thus eliminating the short-term possibility of blackouts for customers and bankruptcy for the utilities, it won't really solve the fundamental imbalance: the state isn't generating close to enough power to meet its long-term needs.
"Biped! Good cranial development. Evidently considerable human ancestry."
Hmmmm.. you mean... an "off" button? ;-)
we could do something like this already. I'm getting tired of reading things like this and having it go nowhere fast. Wouldn't it be cool if we could actually go ahead and do it?
Small mind? Like thinking that we'll be a thriving species without a naturally habitable planet? What the hell did you think I was talking about? At least you troll anonymously.
WARNING: there is a trojan on your
I've read the article, and I've read all the comments, and I still haven't seen anyone guess a feasible design for a reactor/propulsion system using this stuff. Surely there's some nuclear physicists with the back of an envelope handy who'd care to enlighten me? :-)
Any sufficiently advanced technology is indistinguishable from a rigged demo
--Andy Finkel (J. Klass?)
distance = 1/2 * acceleration * time^2
so, if half way from the earth to mars is 8e10 meters, and 1 week is about 6e5 seconds, I make that only about .44 meters/second^2
or 1/20 of a Gee.
(surely I've bollixed the math someplace :)
Shut up, be happy. The conveniences you demanded are now mandatory. -- Jello Biafra
Mainly because the specific impulse generated by this sort of propulsion is pretty low - works really well in the frictionless environment of space, but wouldn't even be able to get a Fiero (motorized skateboard imho) above 1/2 mph on Earth. :)
>Assume getting off earth is expensive, but a break through tommorow turns up with cheap travel between solar systems. That means that the space station can send probes to do fly-bys of distant planets, and 20 years latter have the satilight return for repairs before going to a diffent solar system. (Of course that would be fairly close).
Even the closest star, that is, as you probably know, Alpha Centauri, is four light years away. You would need a probe that moved at near-lightspeed, and even then the round trip would take over 8 years. As far as I can tell, we're not near the required technological level to accomplish something like that.
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"Baka." --Ruri, Mobile Battleship Nadesico
>Of course either 450,000 m/s or 740,000 m/s would give us measurable time/space/mass dilation problems. So you gain a little weight you get a little smaller and you age a littler slower -- basicly you would be young, short, heavy and hauling ass!!!
Even assuming that was a joke (as it probably was), not quite. Light moves at 299792458 m/s, and relativistic effects only become measurable at about 10% of lightspeed, i.e. about 30 Mm/s.
If you have a graphing calculator or a program that can draw graphs (or write your own?), try plotting 1/sqrt(1-v^2/c^2) with v going from 0 to c (excluding c). This is the term that appears in time dilation etc. basic relativity formulas that you're referring to.
Feel free to ignore me, just picking nits with nothing better to do on a Saturday evening. =)
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http://mp3.com/jje
"Baka." --Ruri, Mobile Battleship Nadesico
I agree, to a point. But here's the reality: We aren't there yet. If we started building right this minute, we'd be there in about five years. You're not going to see routine trips to Mars for 10 years at least.
Secondly, the ISS may be the biggest boon to interplanetary space travel we've come up with so far. With it, we have the possibility of starting from outside the gravity well, which is the biggest fuel burn we have with any space travel.
Finally, if you don't like what NASA is doing, why not do it yourself? Seriously, private sector space travel is getting more likely and more lucrative by the day. Go get some funding, and do it yourself!
"People who do stupid things with hazardous materials often die." -- Jim Davidson on alt.folklore.urban
What good is it to have tiny nukes if we have no ability to deliver them to other planets, where hostile alien races are sure to be setting up a similar attack on us? We must strike first to establish humanity's supremacy in the galaxy, and a super-fast spaceship with horrifyingly destructive weapons is the first step.
Phallic Symbols in LOTR
I can think of some much faster ways to achieve it... none legal, of course!
sulli
RTFJ.
Just how many manned rocket launches do think there have been. Not that many. There are literally thousands of people riding Amtrak's rail-ways a year. It's insane to compare rocket's to Amtrak. Even more so to compare it to the individual passengers.
A single train alone holds more passengers than the amount of manned rocket launches the United States has ever had.
Mars is actually between 100 million km and 380 million km. Closest approach happens once every 2 years and trajectories give an actual distance of about 150,000,000 km.
d = v(initial)*t + 1/2(a*t^2)
Since we have a positive acceleration half way and a negative (with respect to earth) acceleration half way, we solve for t = 1 week with a distance of 75,000,000 km.
75,000,000 km = 0 + 1/2(a*1week^2)
7.5*10^10 meters = 1/2(a*604800s^2)
a = 0.41m/s^2
By the same token, a 1G acceleration will get you halfway in 1.4 days, or all the way in about 3 days.
True and false. There ARE in fact things we can put together out of carbon which are superior to any petroleum-based lubricant. Unfortunately, no one has done so commercially. This is mostly because it's expensive. You can see pictures of buckyballs here. CMU has a buckyball project. So does SUNY. You could make your own fullerenes. There are a number of fullerene-related patents.
That last page produces the real gem: this patent is for a "Magnetic recording medium comprising a solid lubrication layer of fullerene carbon having an alkyl or allyl chain". The abstract reads:
There are further supporting references. The Buckyball: An Excruciatingly Researched Report (which gives its references at the bottom) contains this quote:
Of course, I don't know that anyone's actually assembled such a molecule. I located an article called Just Rolling Along which discusses tungsten disulfide, which is similar to buckyballs. It is, however, expensive to produce, and difficult to make in quantity; This is what we're waiting for. Incidentally, I did find one article that gave hope for this, under the heading "Cheap Buckyballs". Amusingly enough (to me) the anchor tag is named "cheapballs". I guess when you're hopped up on this much sugar all kinds of things are funny. If anyone has access to the text of "Journal of Organic Chemistry, March 8" perhaps they could help out here.
So in summary, there ARE better lubricants than those cracked from crude. They are not, however, currently on the market, as they are expensive and time-consuming to produce. However, science marches on, and we'll solve this problem, too.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
actually, the best sheilding for this kind of radiation is. . . water.
That's one reason why in designs for the mars lander/habitat, water tanks are on the top level, so during solar radiation storms, the astronauts can get underneath them.
Water, and magnetic fields, and miles and miles of rock. Not much else can stop it.
These are my friends, See how they glisten. See this one shine, how he smiles in the light.
Oh well, I was modded down for correcting a spelling mistake that's right smack in the title of the post: interplanar? wtf??
Don't sweat the stuff, there are many iiots at Slashdot, and not only among the readers.
Sigged!
I spoke with a friend's father who works for PG&E in the SFO area and he was telling me that Duke Energy, the British company that has been purchacing power plants in California has been shutting them down for "repairs" even though in most situations the repairs are not crittical and can be staggered with regards to the other plants. Thus recently many plants have been shut down, creating an artificial lack of supply. Ahhh the joys of accountants running companies, and the need for creating shareholder value... whoo hoo!
---- Fight to protect your right to keep and arm bears! ummmm... ya I think that's right....
...as kids with matchsticks and gum wrappers
I believe the next launch time we could possibly make is 2014, which some people were hinting at, but if we don't hear something real damn soon it's not gonna happen.
After that, IIRC the sweet spots come every 7 years or so, so I really hope we start working on this now.
To start with the disclaimer, IANAOM (you figure it out)
To shoot down one misconcept, you do not travel to mars in a stright line. To do so would be deadly. I'll explain later.
To get to any orbiting satelite is not a matter of accelerating towards, and them hitting the brakes to stop there. But a matter of matching orbital velocities. When you take off from earths orbit you want to accelerate out towards Mars and get there with your speed being identicle to Mars. If you took a straight line to mars and then waited for it show up... well, it would be pretty.
I wish I had a picture to show this, but I don't. If you looked at a top down picture. The space craft would travel in a curved line so to speak. The trick it to end up traveling the same speed as mars with the same vectors. Then a quick blast would slow you down and drop you out of orbit.
I'm not sure on the math but I know the distance travelled is greater than the line of site distance between the two planets and that the whole trip to mars can be done under acceleration (if you want to get there slowly)
That's about all I know. And I may be wrong. If I am, you have my permission to bitch slap.
You have a very wide definition of American, it seems. Includes the british now, it seems.
Unless you can find some Kamikaze (sp?) astronauts to make this mission, you might want to wait until there is a reliable method for bringing them home. It's much easier to launch a sufficient craft with all of the support infrastructure here on earth, but what about on Mars. The best thing that NASA has done is to promote saftey. Look at their saftey record vs the Russians and you'll see what I mean.
THIS SPACE FOR RENT
Haha, I see you are trying to be funny too.
I suppose you know just as well as I do, that Orwell was an Englishman.
we CAN'T fix this planet we're on.
Otherwise, we'd interfere with people's right to get obnoxiously rich.
These are my friends, See how they glisten. See this one shine, how he smiles in the light.
The proper Hohman transfer alignment window for Mars occurs every 2.2 years. For all other planets it is about 1 year, because the relative orbit velocities are high and Earth takes 1 year to orbit. Since Mars is close to us and orbits at a speed close to ours, it takes longer for Earth to overtake it and go back to a good position.
THIS is why the ISS is so cool. You now have a spot where you can hot stage this stuff in orbit. You can put engines that would be harmful to the earth's atmosphere (or not operate at all) into orbit before you light them off and leave.
... "Ummm ... the software engineer is needed on site for final integration testing ..." yeah! or not.)
There is no longer any need to do a "moonshot" style mars mission where everything needed goes up at once.
Granted, in-orbit assembly will mean that us ground bound types will have more work to do designing/building the vehicle, but talk about a pay off! We could possibly have a reusable, interplanetary capable, spacecraft in fulltime service. (Hmmm this sounds like a great excuse to get me into space
"There's no secret. You just press the accelerator to the floor and keep turning left." -- Bill Vukovich
One road for one million people- nice ratio Orlando.
-p4
(c) All Rights Released.
You do realize that no one was sent to help that sub until it was a "safe bet" that everyone aboard was dead right? I wonder why. Could it be because it would have been too expensive to try and rescue living breathing people, but it was pretty important to get whatever technology was aboard back to the surface?
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It's not because of the decaying Am-241, but the reliability of the electronics starts to slack off after 10 years, they get clogged with dust, etc. That's why its recommended that they be replaced every 10 years. I have an old smoke detector kicking around that is ~15 years old, but it still works.
I totally agree with your point about the oil, though.
-atrowe: Card-carrying Mensa member. I have no toleranse for stupidity.
What frosts my cookies/biscuits is exactly how this stuff is supposed to be stored? If it fissions in paper-thin amounts it has to be a challenge to store, meaning we would produce it en route?
And then we need to paint it to the walls of the reaction chamber without it reacting, let it do its magic/decompose, then make and apply more?
I can see it now, the Mars 1 mission will be staffed by one astronaut, seven nuclear physicists, two materials scientists, and one hazmat worker. :)
Get off my virtual lawn, you damned virtual kids!
Personally, I've always found the best way to achieve interplanar travel is to find a high level wizard who can cast the necessary spells. I like to visit the outer planes at least twice a year.
I have submitted valid stories before and had them all rejected -- I suspect if the editor does not recognize your name then you will be passed by for someone who has posted previously.
I think preferential placement in the submission queue is supposed to be an action of karma, but besides meta moderation there's not a lot that ordinary geeks like thee and me can do to increase ours. :)
Myself, I just assume that sooner or later the über-geeks like CmdrTaco or Timothy will stumble over the information I have found and post it. I resign myself to kibbutz'ing out here in the shadows. :)
Get off my virtual lawn, you damned virtual kids!
to have any posting of mine receiving an elevated score.
I am resigned to being perpetually irrelevant. :)
Get off my virtual lawn, you damned virtual kids!
If something went wrong on a MOON mission, we would ahve left our astronauts out there to die
True, but only if there were no other solution. Remember Apollo 13 (the mission, not the very good and ultimately enjoyable movie)? NASA and friends did everything in their power to bring the boys home -- when it would have been much less expensive to just turn the radios off, send all the engineers home, and tell the media that they lost contact with the astronauts.
--
SecretAsianMan (54.5% Slashdot pure)
Washington, DC: It's like Hollywood for ugly people.
What would we do? Well, for one thing, it would ensure the survival of the human race. Transporting the entire population of the earth? No need, people breed quick enough. This may sound callous, but it's true. Given time and willpower (money is irrelevant, it's just an extension of willpower), it is possible to terraform Mars, at least far enough to grow crops on the surface. I realize this is no trivial task, but has that ever stopped humans before?
Coal fired power is evil, regardless of benefit.
Oil fired power is evil, regardless of benefit.
Natural gas power plants emit pollutants and so are evil too, regardless of benefit.
Geothermal and solar... hmmm... don't seem to work like greenpeace says.
So for the last ***10 YEARS***, not one new power plant was build in CA nor any expansion of existing plants.
Waaaaah! We have an enegry shortage in CA due to... uh.... yeah!.... DEREGULATION! Surely strict environmental laws are not to blame. And repealing then would be a right wind radical thing to do.
Let's lobby the DOE to force other states on the grid to sell us power at a mandated discount. They want to suck off the grid and pollute other states so they can have blue skies?!
Well, hey, CA, you download off the grid, you have to upload too. CA is no different than a w4r3z l33ch. If you want power, you have to get dirty... you have to pay for it just like everyone else.
With critical mass for Am-242 at 1% of Pl-239, then about 20 g. would make a mini-nuke. That adds one more worry to storing the raw material - security.
Ma certo:
distance = 1/2 accelleration*time^2
The closest distance between Mars and Earth is about 100 million kilometers (I refuse to do this in miles)and want to cover it in a week
0.5*acc*(7*25*3600 second)^2=5*10^10 meter
Gives you about 0.27 meters/second^2 or about 1/40th of Earth's gravity. Peachy
Well spoken.
Blar.
I'll check the DU training slides I have at work. I don't think they're classified or "For Official Use Only" (although as soon as you start getting into this kind of stuff, things do tend to get classified, whether they need to be or not). I'm sure I can post the relevant info.
Let's do some math:
Accelerate at 1 G for two days...
10m/s * 60 * 60 * 24 * 2 = 1728 Km/s
Mars is about 20 light minutes away at its most distant point so...
20 * 60 * 300,000km = 360,000,000 km
At the aforementioned velocity you could cover the distance in...
360000000 / 1728 = 208333 secs
That's about 2.5 days, no puree.
Sure I agree in theory that we need a cheap way to get off earth before we need a cheap interplanitory travel. However it turns out not to be stricktly true.
Assume getting off earth is expensive, but a break through tommorow turns up with cheap travel between solar systems. That means that the space station can send probes to do fly-bys of distant planets, and 20 years latter have the satilight return for repairs before going to a diffent solar system. (Of course that would be fairly close). reusable probes would be a break through, and while they are still expensive they would be a lot cheaper then starting with a new probe, and would give us data we cannot get today. (We cannot do a fly-by of other solar systems with current probes, but this might give is the ability to do fly-bys of farther out systems)
Second, and more likely is that eventially we get a fairly cheap way to get off earth. We don't want to start at ground zero devolping cheap interplanitory travel. A lot of early work in research is better done by small teams, once the theory(s) are devolped you then take a large team to impliment it. So once we have a cheap way to get off earth we really want to quickly get a cheap way to get elsewhere. Getting off earth might end up taking 3 hours, who cares, but if that super cheap drive that takes 3 hours to get off earth can't reach faster speeds it is wrothless for getting to mars. Take that cheap but slow drive as a farry trip to space, and switch to a ship with cheap interplanitory drive, and you can then reach mars in 2 weeks. Nobody would allow a ship with radio active by-products like the above in the earths atmosphere, but it si harmless in space, so we combine them.
I get the same answer. But remember that velocity isn't necessary indicative of the situation. What you have described is constant acceleration and deceleration. If that is so, then at the point of change over, ie. the time going from speeding up to slowing down, the spacecraft in question is traveling over 266 km/sec. This tranlates to 16 thousand km/hr.
Fast, huh.
Eric Gearman
--
Atomic batteries to power! Turbines to speed!
Drink two cups of I-131 and call me in the morning.
Friends don't help friends install M$ junk.
Evan - needs to hit preview before submitting
How does it go? "Never attribute to malice what can be attributed to stupidity"?
:-)
There was a project at a university supported by the automotive industry to develop a nuclear-powered car, but then there was this little problem at Three Mile Island and the funding pretty much disappeared. Add to that two things: (1) The researchers had made little progress to the auto makers goal, though they did a lot of research that is important for other things (materials research); (2) There has been a propaganda machine (mainly by the US Gov, I guess) to scare the sense out of people wrt radiation - our "nuclear deterrent" is more effective when people are afraid of it.
You can find out about the automotive research by looking for something like "nuclear-powered car" on Google. (Sorry, don't remember the name of the project off-hand.)
IEEE Spectrum had a good series about Three Mile Island some time ago; but I don't have the issue numbers.
Physics Today, Physics News, or Science had an article in the past year (or 2) about the dangers (real and imagined) of radiation et al.
Last Note:
Present day nuclear reactors use fission; fusion is still a pipe dream; Cassini (and many other space probes) used RTG's (RadioThermal Generators) which rely on natural decay processes; a nuclear bomb is a very complicated machine - a fission reactor in a car (which is probably unnecessary, see RTG's) might 'meltdown' or leak radiation, but it wouldn't become a bomb. The worst-case scenario is probably (and this is just a guess) that the car could explode just as it could with conventional fuel (and how likely is that? *shrug*) and then there would be some nasty clean up to do _if_ the design is so poor as to not contain the fissionable materials. Keeping the reactor safe from an external explosion is 'easy' - we know how to do it. Making a cheap, low-maintenance, and self-containing reactor is probably the hard part; but mostly because of the first two parts.
My memory is a little fuzzy, I'll check these #'s after I post this :-)
24 Men went to the moon. 12 Walked on it. 3 Made the trip twice.
In any case, you don't have the luxury to perform atmospheric braking with humans on board; It's a bit too dangerous for that. So you have to slow down and weasel into a stable orbit manually, a non-trivial task.
1) Atmospheric braking isn't too dangerous for humans. That's how every single person who's even been sent into orbit got back down.
2) Orbital insertion via aerobrake is a hell of a lot harder than orbital insertion via rocket.
Now, there's not much point in aerobraking anyway, in this case. Aerobraking saves you a ton of fuel at the destination. It's actually cheaper to land stuff on Mars than the moon because of this. However, if you're accelerating the entire way there, it's not going to save much fuel, and fuel doesn't seem to be a worry anyway.
Mod down posts with a "Free Mac Mini/iPod" sig, they're spam!
1G accelleration for a week gets you -
1,792,336,896 km.
Harrison Ford already proved the mechanism for interplanar travel in Air Force One! Just use a rope and slide from one plane to the other.
That's nothing...
At a college I used to go to, they were using smoke detectors that were 20+ years old at the time. The things were so old, the housings were made of metal.
They still worked, er...sortof, I remember that false alarms were somewhat common under certian conditions, namely conditions that stired up alot of dust and pollen in the air.
Newton's Third Law of Motion (ok, Newton was wrong, but he's close enough for our purposes):
:)
Every action has an equal and opposite re-action.
The fuel in a rocket is thrown out the back, the re-action is the rocket being pushed forward. The rocket being pushed forward pushes all the contents along with it, and the re-action is all the contents pushing back on the rocket. Plenty of forces working in there, and it has nothing to do with the presence of an atmosphere.
The MIR, ISS, and space shuttle do not travel in geo-stationary orbit. They all travel in a fairly low earth orbit, IIRC the space shuttle takes 90 minutes to circle the Earth. The only reason why objects in orbit do not experience gravitational effects is because, in fact, they are really in a constant free-fall. If you ever find yourself in a free-falling elevator (hopefully not) you will see what I mean. They are in constant free-fall, but are moving so fast tangentially that the Earth curves away beneath them as they fall.
Physically this is described: Gravity provides the force necessary to maintain the radial acceleration necessary to sustain the circular orbit (assuming a circular orbit).
The relevant equations are:
F = mv^2/r (radial acceleration to maintain circular motion)
F = GMm/r^2 (Newton's gravitational equation)
M is the mass of the earth, m is the mass of the spacecraft, G is the Gravitational constant 6.672*10^-11, r is the distance from the center of the Earth.
Putting them together in a system:
GMm/r^2 = mv^2/r
GM/r = v^2
v = sqrt(GM/r)
Which is the equation to calculate the velocity v required for a circular orbit at radius r around planet of mass M.
(sometimes I wish LaTeX, not HTML, was the language of the WWW
I do highly suggest picking up an elementary physics book, because many of your notions are easily correctable even by a basic text.
Those who do not know the past are doomed to reimplement it, poorly.
Am241 (the isotope used in smoke detectors) still emits some gamma radiation. In gram quantities, this can pose a health risk.
Although Am241 is used as a alpha source in smoke detectors, most detector contain less than 5 miligrams (1 microcurie.) Most of the radiation is shielded by the smoke detector housing.
Of course, the radition risks posed by Am-242m, the isotope used by this particular space probe, will almost certainly be different.
(For instance, Am241 has a halflife of 432 years, Am 242 has a halflife of 141 years. Both emit alpha particles, though)
Anyone with any knowledge of American history would not have moderated this down. It should be modded "Funny".
>HIS EXCELLENCY NORTON THE FIRST, EMPEROR OF THE
>UNITED STATES AND PROTECTOR OF MEXICO, CLAIMS THE
>MOON FOR HIS GLORIOUS EMPIRE! ALL HAIL NORTON I!
No sig? Sigh...
Anyway, I heard a Chevron station in Orlando, FL accidently got a delivery of this stuff and their State Troopers wrote a record number of speeding tickets that month.
-p4
(c) All Rights Released.
Now, call me crazy, but people keep assuming that an in-atmosphere launch is a given when dealing with spacecraft. I doubt very much that this drive is intended for use in an atmosphere, and I know for a fact that both Project Helios and Project Orion were not intended for use inside the atmosphere of Earth.
But, since you mentioned them, I just want to comment on Projects Orion and Helios, related to this article by the fact they too were potentially great boons to space travel way back twenty years ago: Having become aware of the projects way back in the eighties because of a children's book(!) I began to research as much as I could on the projects. I really began to gather information when I got connected to the internet back in 1996. The internet is a wealth of information but in this case 98% of what you'll find will be either pure dross or pure fiction dressed up in science sounding terms. I'll add "in my opinion" rather than just state the above as a fact - IANASY (I Am Not A Scientist Yet). I've let my search lapse in the last few years mainly because of all the extra fake and useless info that appeared on the internet after films like "Deep Impact" which briefly mention Orion or Helios. But from what I gathered, the official reasons the projects were terminated rather abruptly were highly unlikely, the main one cited being the SALT (Strategic Arms Limitation Treaty) and SALT-II treaties with the Soviet Union. A second reason often given was that the '...radiation problem caused...[by the detonation of nuclear devices]...an unavoidable health risk[to the crew].."
Looking over the technical details I managed to track down, I do not believe this reason. Even with limited knowledge, most people would be able to proffer ways of protecting a crew from any major health risk - working only on a design basis. Fears of contaminating the Earth's atmosphere seem unjustified considering it would be possible to limit operation of either the Orion or Helios drive(for want of a better term) to an acceptable distance from Earth. I don't mean to spread paranoia, but at the very least the people who cancelled these projects were misguided - I leave any other alternatives up to your imagination!
I'm not an amoral person who puts science before people : NATO's use of DU(Depleted Uranium) based weapons is deplorable; fission is an unsafe and unnecessary technology for use in power stations; the use of growth hormones in livestock farming and relatively untested GM techniques in Agriculture is plain crazy in Western economies. The fact remains that Orion and Helios were two projects which shouldn't have been cancelled. I hope to goodness that, just because this new drive employs a radioactive isotope, it isn't designated 'too risky' out of hand - which seems to be a popular thing to do nowadays. (By the way, I know it's a different isotope, but check your smoke alarms....there's a good chance it contains Americium 241 (probably about 0.9 micro curie)
(By-the-by, if you're planning to look for info on Orion or Helios, try the following phrases "Advanced Propulsion Design", "JPL", "Helios" and "Orion" You'll also find that various university professors have, at one time or another, written papers on the subject - try contacting your local university's physics department. )
8)
Concrete analysis...
Still, calling all that math "completely, absolutely, and utterly wrong" is a bit harsh, IMHO. It's still just a question of finding two vectors, one for acceleration and one for decceleration, and the math presented here is at least a rough ballpark approximation of the G forces likely to be encountered, enough to show that humans won't be turned to mush by a two week trip to Mars.
"Mind, as manifested by the capacity to make choices, is to some extent present in every electron." -Freeman Dyson
The only hope is to include a device on board the spacecraft which produces Am-242 from more stable elements. But this eliminates all the attractive features of using Am-242 in the first place!
I suspect you really don't mean that; "terraform" is usually used to denote the transformation of a planetary surface into a terrestrial environment, and there's no asteroid large enough for that -- they wouldn't hold water or an atmosphere.
If you meant "hollow it out and make a living environment inside," or even "use the materials to create a space habitat," I agree with you. Just being pedantic... ;)
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Politics is about making compromises. Religion isn't. --Michael Horton
Think about it, it would work. For any apple story insert some lame comment about jobs from a fortune database. For linux stories some comment like "I'm glad to see that linux is finally immanitizing the eschelon".
Gack! I've figured out to much. The VA linux corporate assassins just knocked down my door and are in my office.
Fortunately since the collapse of their stock they couldn't afford competent assassins, nor weapons beyond a broken nerf gun purchased at a garage sale for a nickel.
Chris Kuivenhoven is a thief, beware
It would be great if we could get millions of space robots in a huge swarm to go to mars, way cooler than big American mines bigger than yours rockets, if they are small they could catch solar winds, once there the swarm " collective " can move all over the planet maybe relying what they can to a mars orbit satalite , that will process and put some order into the small amounts of info each nano probe gets or certain gouping , and if they all blow up who cares cause they should be cheap and there should be millions of them. just a idea, dont whinge if you think im nutts cause i dont care
Notice they're using americium . . . we all knew America was supposed to win the space race ;)
OK, so you're not that much younger than your twin brother, but you are by as much as 4 seconds. :>
Nuclear powered spaceships can be built and operated that so that they won't harm the Earth. Build them on the moon and operate them in deep space. The Moon has lots of thorium, uranium and other radioactives to mine.
The moon is already a radioactive hell from solar radiation. It has no living environment, its a dead world with the resources we need to supply our civilization.
The enviornmentalists must recognize that industry must move off the Earth so we can clean it up. It could involve some short-term environmental expense to the Earth, but in the long run moving polluting industry off the Earth is essential.
To the Moon!
http://www.beefjerky.com
The problem with going at 1G for a week is special relativity. 30k times the distance to pluto is on the order of 100 light years, so there's no way you could get there in a week. However, this isn't a problem on the trip to mars, as you'll only be going .3% c
The G-force isn't that bad, actually.
brittanica.com tells me that the distance from Earth to Mars is between 56M km and 400M km, depending on the relative position of the orbits.
Assuming constant +ve accn for the first half of the journey and constant -ve accn for the second half, and a two-week journey in total, this means an acceleration of between 0.15 m/s^2 and 1.1 m/s^2.
Since 1g = 9.8 m/s^2, these accelerations are tiny, and you'd safely avoid being pureed.
All opinions expressed herein are not my own; I haven't had free will since last year when aliens ate my brain.
I've commented on this in the past, and gotten slapped down immediately, but it's worth bringing it up again.
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You are a fucking moron.
If we have an affordable way to travel in months to the nearby planets, then the solar system and the stars are open to us.
the model is that of the Polynesians as they spread over the Pacific ocean. There plenty of small objects beyond Pluto that could act as stepping stones. never mind things like the asteroid belt. Earth crossing asteroids could suddenly become viable economic entities for carrying things between the inner and outer solar system
There are many problems of supply that would have to be worked out. But we could certainly build a network over time, terraform an asteroid or two, mine a comet for water. the challenges are formidable, but not out of the question.
"It is a greater offense to steal men's labor, than their clothes"
Anyway, I never could see why people get so worried about us using up all of our oil. It's all simple economics: right now, it doesn't make sense to look for a new fuel source. We have plenty of oil, and it's not doing any good where it is. When it becomes too expensive to obtain, we'll find another energy source real fast.
How can we continue to believe in a just universe and freedom to eat crackers if we have no ale?
Sure, there's nothing wrong with the cgs system (centimeters, grams seconds).
I like it beter than mks mostly because 1 cm^3 = 1 ml = 1 gram (water).
Much better than 1 m^3 = 1000 l = 1000 kg, IMVHO.
Besides, when your talking space flight, everything is exponents anyhow.
- dave f.
If this super-duper stuff can get a rocket to Mars in two weeks, couldn't it run a power plant too? A thin film of Americum spinning a turbine to make electricity would be much more useful than a rocket to Mars.
Now if we could only put the stuff into a Delorean...
Hm...maybe we should get an atmosphere up on mars first.
2001-01-04 22:49:49 New Nuclear Spacecraft: Travel To Mars In Two Week (articles,science) (rejected)
Maybe each editor should be required to give his name when rejecting a story, so as to take responsibility. He might even give a short reason for the rejection--just like moderators have to give a short reason for their scoring.
YHBT. HAND.
(jfb)
PS: Fuck you taco, and the "lameness filter" you rode in on.
To spur "enterprise Linux," Big Bang, the distributed two-phase commit.
The one-shot approach to interplanetary travel is dumb. We should be creating "shipyards" in orbit, maybe even at L5 or L4 so they benefit from being farther up the gravity well. We could mine water on the moon, along with needed metals and whatever. Setting our sites on Mars too soon is going to leave us with an Apollo-esque hangover, where we don't begin colonizing the Red Planet in earnest for another hundred years anyhow, so why be in a big rush?
I think the "send robots" contingent is mostly right: there is no reason to have humans there, unless you send them to live there. Solar System Tourism should NOT be part of NASA's mandate... they should be focused on doing good science and creating a viable infrastructure that we can build on for the next few centuries instead.
So, I say... Start robot-mining on Luna, the moons of Saturn and Jupiter, Mars for sure, and maybe Venus and Mercury when the technology becomes a little more sturdy. Setting up operations in the asteroid belt would be smart too.
Make more megawatts!
Friends don't help friends install M$ junk.
Why do smoke detectors need to be replaced every 10 years? I thought it was due to the radioactive material decaying too much. But if the half-life of Am241 is 432 years, then after 10 years the Am241 concentration only drops to 98.4% of its original value. Seems to me these things should be good for a lot longer than that. 50 years brings it down to just over 92%. Still seems like plenty. Is there so little tolerance in Am241 concentration for the proper operation of a smoke detector? Or is there some other reason for the replacement timeframe?
It does look like using americium would simplify things... But, since large scale americium production appears to require the use of breeder reactors it is a political dead end in the US right now.
I hope someone has the guts to try it.
stonewolf
Your calculations would be great if you were flying from point A to point B in a straight line, but unfortunatately it's not that simple.
:) So not only do you have to worry about the eccentrities of getting into a Solar orbit at Mars' distance, but you have to time the process such that Mars will be there when you arrive. Depending on the positions of Mars when you leave terrestial orbit, this can be non-trivial.
:)
Firstly, you're moving about in Sol's gravity well, so you can't just point at Mars and pull the trigger. Instead, what you want to do is move into a higher (faster) orbit around the sun.
Secondly, Mars moves!
I Am Not An Orbital Mechanic, and perhaps someone who is could do the real math, but I think that the distance covered is far greater than you've assumed.
However, it seems to me that the accelerations involved are still not extreme. I may be wrong, but I think that a 1G acceleration gets you to Mars in ~ 2 weeks, taking orbital mechanics into account. 1G is a magic number, as it would simulate the gravity you're experiencing now - good for bone mass retention.
Want to learn about race cars? Read my Book
Is the "two-week" travel time estimate an estimate of Proper Time (experienced by the time-dilated traveller) or is it earth-clock time? Under a modest-yet-constant acceleration, you can get up to relativistically-significant velocities pretty quickly.
Most smoke detectors use the stuff, in fact if you get enough of them together you could build your own mini power plant.
BTW that was a joke, your supposed to LOL!
--toq
There are some people who like suffocation, just ask the former lead singer of INXS.
Friends don't help friends install M$ junk.
We have few enough "launch windows" available between mars and the earth if we're launching from the earth. Gods, what are we going to do if we start launching from the moon and our launch window becomes a few short hours when the moon is between earth and mars?
We miss one of those launch windows, we have another month until we can launch again.
Remember when NASA was under pressure to launch during inopportune launch windows? Challenger.
"One touch of Darwin makes the whole world kin." George Bernard Shaw
Speaking as a nuclear engineering major, I have to say that getting americium is actually pretty easy. Separating the different elements from the spent fuel in a reactor can be done through electricity or steam. As we all may remember from high school chemistry, or not in most cases, electricity separates elements in a solution. This might not be the best way to do it, but it is possible. Steam is a whole other long explanation that I don't know the exacts of but I know the gist of it because I'm not a fission major, I'm plasma :) Anyway, Americium is definitely an idea, but from what I remember, americium is one of the weaker radioactive elements. We might be better off using something better. But then again, I am a plasma major so I support plasma rockets :)
If memory serves, there were offers of help from all over the world pretty quickly after the news broke. But the Russians wouldn't accept help for quite a while.
If a nuclear fueled car had to be refueled every 300 miles and that fuel costs the same as a tank of gas at current prices, believe me, someone is gonna get rich off of it. It can be done today: Drive an electric car, then at a charging station fed by a conventional nuke plant, plug up, then pay for however many kilowatts it takes to recharge. Better yet: Have a standardized battery pack, then swap out dead batteries for freshly charged ones, then pay the cost to charge plus a nominal maintenance fee. That way you're off and running after 5 minutes, just like filling a tank of gas. Too bad there's no way to deliver nuclear generated electricity to cars like a cellular phone signal.
I think a ship that would use this kinda fuel would be constructed in orbit and leave from orbit. I dont know why so many people think of radioactive exhaust and radioactive contamination as major issues with this. Yeah, the shuttles carrying the fuel to orbit could blow up, but so what, shit happens, the stuff would be in a nice safe container of some type or another.
For those of you who worry about it, go watch Trinity and Beyond, its a great film about one of my favs, nuclear explosions. After you see all those, a small spacecraft is peanuts.
I want to go to space. meet some 3 titted chicks!
Shut up, be happy. The conveniences you demanded are now mandatory. -- Jello Biafra
It's amazing what one neutron will do....
Am242: fuel to mars
Am241: Smoke detectors!
Paul_D
OK, very roughly:
Earth 1.52E13 cm from Sun (max)
Mars 2.06E13 cm from Sun (min)
so min of 5.4E11 cm distance between them.
2.7E12 cm = a/2*t^2
About a 60th of a G? Hmmm, kinda low, but since it is only for two weeks, I doubt someones bones would completely deteriorate. No, not puree, but you should exersise, or else that 1/3G on Mars will seem a little more.
- dave f.
So what happens when friction from interplanetary gasses happens, does solar radiation slow it down, when asteroid belts get in the way is there a carmageddon style "instant-without-killing-me-handbrake" ?
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Video meliora proboque deteriora sequor - Ovidius
these accelerations are tiny, and you'd safely avoid being pureed
I just dont wouldn't want to be turned into another Deep Impact probe.
Karma karma karma karma karmeleon: it comes and goes, it comes and goes.
Well, if we just count manned US Space Shuttle launches, the error rate is only about 1% out of 100 launches. I'm not a gambler but I'd take those odds any day over Amtrak. You might survive the trip but you'll probably get mugged in the parking lot.
FYI, americium is also used in ionization type smoke detectors.
Am 241 has a half-life of 432 years? Thats odd, thats the same material used in the ion chamber in these type of detectors, and those things have to be replaced once every 10 years...
> I'm sick of waiting and I'm sick of watching NASA shoot little AIBOs
:)
> at that planet and then watching them crash and burn.
Yeah, let's shoot big manned AIBO's, and watch those crash and burn instead
If I were to endure a 2 week acceleration/deceleration trip to mars, given the distance, I'd be puree on arrival.
You would be completely comfortable the entire time if the acceleration were kept around 1G. Since we are currently experiencing an acceleration equivalent to that all the time. To turn you into a puree we would need to use a wood chipper.
The real hazard comes from little chunks of rocks hitting you while you are moving. This could turn you into swiss cheese to stick with the food motif.
When I want your opinion I will beat it out of you.
LOL! I just can't believe this comment was rated as Insightful, not as funny!!! :-)
Americans, oh, they will never understand doublespeak
"Using a thin metallic film of americium-242m, a rocket could reach Mars in only 2 weeks." Me: Bill, I got here in a split second eventhough I live across the nation...now can I test that xbox? Bill: Wow, let me see that ship u have there...oh yeah of course you can test the xbox.
Those damn aliens. They already polluted it before we got there!
It's the least we can do, if we're going to go to Mars!
"Umm..."??
What do you mean, "Umm..."?
Do you know not know your fact with confidence or are you just trying to put that little twist of innocent-nastiness in your message to make the poster feel bad?
I was beginning to hope that this mean spirited posting trend was dead. Go back to Jr. High, you jerk.
-Fantastic Lad. --The Pouty and Grumpy Today Lad.
Am I the only one who finds it funny, that the element is called Americium?
Which is, of course, just another one of these funny coincidents. ;)
he-sk, non-American
Free Manning, jail Obama.
If this can be made praticle (and lord knows getting americium is damn near impossible!) it make the possability of space exploration more inviting and less risky. The time to arrive at our destinations is greatly decreased and the saftey factor goes up. Just think, a trip to the moon could turn into a "three hour tour".
I for one hope they make it work.
"Science is about ego as much as it is about discovery and truth " - I said it, so sue me.
However, Warren Birch disputes this claim.
It's nota my planet, monkey-boy - Dr Lizardo.
i wanted to know about linux...not rocket fuel.
www.droppingdimes.com
Hell, you might even get as far away as Nevada where hundreds of above ground tests were made. Total effect = 0. Geography is large, Kenedy was stupid, Las Vegas is the perfect launch site.
Friends don't help friends install M$ junk.
Can I go to the negative material plane?
(I think you meant Interplanetary.)
If I were to endure a 2 week acceleration/deceleration trip to mars, given the distance, I'd be puree on arrival.
Karma karma karma karma karmeleon: it comes and goes, it comes and goes.
If the half-life was 16 hours, it would be useless for rocket fuel -- sort of like fueling your 4x4 with something that would get you out in the wilderness fast, then evaporate before you could turn around for home. But it turns out that AM-242 has a 16 hour half life, while Am-242m has a half-lfe of 141 years.u shin/StudentProjects/ElementWebsites/americium/fac ts.htm
http://web1.caryacademy.pvt.k12.nc.us/chemistry/r
I couldn't get into the article, but it sounds like the idea is to cause thin sheets of Am to fission, and just let the fragments fly out the back of the rocket. Might be a pretty good fuel, but it's going to be horrendously expensive -- you probably would need a few times the final weight of the ship in fuel, and this stuff is synthesized in particle accelerators... Anyone know the exhaust velocity, that's what determines how much you need?
not Americium.
Thank you.
I can already see the ads for this...
Dude opens his concrete-and-lead fridge, pulls out a can of Nuke cola, cracks it open. Cut to stock footage of nuclear weapons tests. Back to dude sitting in crater, face caked in soot, mumbles "Woah" or some other banal exclamation.
Then the motto:
Nuke Cola, It'll blow you away/It'll vaporize yo' ass/It'll make you die, or something.
Let us hope that not to many people complain about the use of atomic fuels. I think that this is the greatest thing happening.
michael
if you see me, smile and say hello.
I think all these stories about pie-in-the-sky technology that we won't see for decades, if ever, is entirely the wrong direction to focus attention.
I want NASA to go to Mars, not in 50 years, not in 20 years...now, or 5 years ago even better. We have the ability and to go, we have a plan(Mars direct). All we need is some vision: from our representatives in Congress and from the public.
I'm sick of waiting and I'm sick of watching NASA shoot little AIBOs at that planet and then watching them crash and burn. Spend some money, build a good, safe ship, and send some people there. But for god's sake do it now. Everyone thinks it would be hard, and they'd rather it be easy. Well guess what, it will get easy, once we do it 100 or 1000 times.
And while I have nothing against ISS, that $60 billion could have got us a round-trip ticket to Mars, instead of Mir2.
Ok, so why are we still using gas-powered vehicles?
Nevermind, I'll answer that myself: because oil still exists in the Earth and therefore not every penny that can be made from it, has been made by the perto companies.
So if this nuclear material can be used to send a rocket to Mars in 2 weeks, then assumming it can be controlled and throttled, for how many years could it power a car running at 60 mph.
For example, the Space Stations would be used like airports. A shuttle would take people from the Earth to the ISS. Then from there they switch to a smaller spacecraft, designed soley for travel in space, from the ISS to another orbital Space Station going around Mars, the Moon, or anywhere. Then from there, they switch to another craft designed to land on the surface and take off again.
Space Stations can store up supplies using robot ships, like with Mir. When everything is ready, send the people. The Space Stations can also be built in Earth orbit and slowly sent to the Moon and/or Mars. Who cares if it takes a year.
Space Stations are also modularized so you can tack on what you need where you need it. Kind of like expensive Legos. New modules can be constructed in Earth orbit and slowly sent out to existing stations to add or relpace functionality of the older modules.
Space Stations should be the groundwork for a mission to Mars just like the Gemini missions were the groundwork for the Moon landings. We work out the bugs by setting up a station in Earth orbit (ISS) and one in Moon orbit. Test out every thing we need to accomplish on a Mars trip. Once we demonstrate that we can do those things we set our sights on Mars. Then while we wait for the planets to align for the shortest possible trip for a man, we can work on setting up a station in Mars orbit. Send modules and supplies in robot ships and link them together there ahead of the people.
On a side note, working out this technology for Mars will make having a constant presence on the Moon that much easier. The next step being the colonization of the Moon.
not all of us like to read Michael.
Friends don't help friends install M$ junk.
a rocket could reach Mars in only 2 weeks
Reaching Mars in 2 weeks means the rocket would have to accelerate really fast. But when it gets there its going to have to slow down to land. Is this accounted for in the speed claims? Like in the movie Space Balls, they were traveling at "ludicrous speed". They wanted to stop but they were going to fast, they had to slow down first.
If you're not on somebody's shit list, you're not doing anything worthwhile.....
Anyone remember how fast Helios B went? I think it was around 57,000 miles per hour.
I compeletly agree with you. I think an abundant source of energy can be harnessed from the hot air that environmentalists generate.
...
Steve's Computer Service, Hobbs, NM
I'm sure they'll use conventional engines to launch it into space, and then use the nuclear engines once the rocket is safely clear of the planet's orbit.
I couldn't get to the site, but from the write-up, I'm sure the actual amount of nuclear material used in the engine is small.
Americium is the same element they use in household smoke detectors. That means we can build our own mars vehicles!
-Chris
...More Powerful than Otto Preminger...
Maybe it's time to start building support for a constitutional ammendment that specifically forbids prosecution for consensual crimes.
Maybe the state's highest function is to grind out insoluble problems. (Zelazny, Hall of Mirrors)
I think in this decade, we're going to see advancements in spaceflight technology that will make a manned mission to Mars not only wildly possible, but cheap. It'll be simply obvious for us to go there.
Honestly, I'd like to see a permenant Mars occupation in my lifetime. We need to survey the planet for raw materials, energy sources (solar, or even geothermic), heck even water.
Earth isn't going to support us for very much longer. Space programs have always brought about new inventions that have changed our lives.
I needed to correct my mismod with this comment
Here is a link to the same old story posted by michael yesterday.
Secondly, the ISS may be the biggest boon to interplanetary space travel we've come up with so far. With it, we have the possibility of starting from outside the gravity well, which is the biggest fuel burn we have with any space travel.
The ISS is in LEO. If the earth were a peach, then the ISS would lie somewhere in the fuzz. While I'll grant that it's higher than the ground, it's not enough to make a significant difference in cost. You might think to construct spacecraft in situ to reduce costs, but then there's still the expense of transporting the raw materials and/or parts up to the ISS.
You're not going to see routine trips to Mars for 10 years at least.
I'd push the date back even farther than that. Manned colonies on Mars are still pie-in-the-sky dreaming for the most part. Zubrin, while a visionary, is like most visionaries in that his ramblings need to be taken with a grain of salt and a healthy dose of reality. "Living off the land" sounds very appealing--very "Wild West" and "Lewis and Clark." But it's also foolhardy when you realize that we simply don't know what we need to know about Mars to be able to make such a scheme work. Lewis and Clark could make canoes when they needed to cross rivers. It's doubtful that a manned mission would ever have the resources to build, say, spare fuel cells or atmosphere-transmogrification-into-rocket-fuel facilities as Zubrin envisions. Then there's the problem of cosmic ray bombardment both in the trip to Mars and in the time spent on the surface. The most recent estimates based on our best information to date puts human exposure in the 0.5 heavy nuclei/year/cell in the body range for the trip there, and something like 0.1 heavy nuclei / year while there. This doesn't sound too healthy to me. Shielding won't work very well either. Unless it is very thick (and thus, very expensive), the result will just be bombardment by showers of secondary particles, rather like ricocheting bullets inside tanks.
We have to face the fact that unmanned space exploration is all there will be in the near future. When the robots teach us enough that we can bring the risk (financial and safety) down to acceptable levels, and when we find enough impetus to go there in person, then we might consider manned missions. Not until then, I'm afraid.
We will meet again where there is no darkness.
Friends don't help friends install M$ junk.
Sure, we can go to Mars in a year or two with Mars Direct... but consider:
Fourty some years ago there were several methods for getting to the moon under consideration - among them were:
We went with Moon Direct - and sent 12 (14 if you count Apollo 13) people to the moon. Since then nothing.
Perhaps if we had gone the other way, we would have built the space station in LEO first. Used it as a staging point for missions to the moon and been left with an easy jumping off point for further missions to the moon, mars, and beyond.
I fear that if Mars Direct is the way we get to mars, you will be able to count the missions to mars on the fingers of one hand.
While it may seem that Israelium or Bosnium would have more explosive energy a close inspection of Americium reveals two sub-elementals called Dumbium and Moronium in a nearly perfect balance tightly bound together by Floridon particles, hence the potential for massive amounts of Duh particles to propel the craft. It's all very simple really...
Mars is a much smaller planet than the Earth, it gets less than half the sunlight, and it's completely arid. Transporting the entire population of earth there would require a hell of a lot of Am-242. Then when we get there what would we do? We need to fix this planet, not move on.
WARNING: there is a trojan on your
Okay, so the idea is to make it to Mars in two weeks. What about going to other places in the solar system? Say, Jupiter...Europa...hmmm. We could literally send folks out there and keep sending materials to follow them. Forget about having to recycle every atom one takes to Mars, if the trip is hardly longer than a moon shot, I think we've got it covered.
Right now, the biggest problem with getting to Mars is being able to keep people alive for the 2 years (or something like that) round trip. Watch out, now we'll do it for you in six minutes! Oh, wait....
This is why I check Kuro5hin everyday and Slashdot only when I feel masochistic.
Really? I did exactly the opposite. K5 was pissing me off with countless "meta" stories, articles that blathered on and on about the "community" to the point of nauseating over-analyzation. On top of that, the front page hardly ever changes.
So now I check Slashdot everyday, and K5 only when I feel hopeless bored.
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"Every artist is a cannibal, every poet is a thief."
This new nuclear space fuel is rare. Therefore, expensive. Will the cost be lower than current fuels? Can we develop a method of obtaining/creating AM-242m that is less expensive? In addition to the cost of the fuel, you might also figure in the cost to get it into Earth orbit, as I doubt you'd want to launch this thing from within the atmosphere.
Here's another kicker: Can we find/make AM-242m at our destination(s), or must we carry along enough for the round trip? If we can make it out there, we can make the trip even cheaper by not carrying as much fuel. Asteroid mining, anyone?
Little girls, like butterflies, need no excuse. -- L. Long
Ya know, you're right. Let's get rid of all of that nuclear powered stuff, expecially in space. After all, we don't want to spoil that wonderfull pure environment out there with filthy dirty icky radiation.
Of course, the first, and biggest source of nuclear radiation we'd have to get rid of would be the sun, and all of those other stars. Did you know that they pump out enough radiation to kill you if you go out there without shielding? We'd best hurry to get rid of them first, since they give off a whole heck of a lot more radiation, AND radioactive crud than any rocket we build could manage to do.
Well ... they obviously will be coming back to earth, what if Entry into Atmosphere fucks up and the ship gets ripped apart ??? Ok, the astronauts are dead, but what about the Nuclear fuel ??? Burn up ??? maybe some of it ... the rest is gonna come down on us ... ok ok ... won't be that much ... but let that kinda thing happen a few times, and we will not only have acid rain ... ...
Nur die Harten kommen in den Garten
i was reading an article in a Scientific American from a few months back about the vasimr propulsion system. it can get up to 300km per second and seems to be very fuel efficient. check out SciAm's comparisons.
The weaver becomes the web, the machinist the machine.
Mankind is truely to invent something completely different if we want to go anywhere besides our space backyard.
Most propulsion systems today still use the principle of throwing wast amount of mass in the opposite direction of where you want to go. It could be throwing suitcases for that matter (powered by a thousand monkeys throwing an infinite amount of suitcases!)
Longer travel => faster you want to go => more mass/fuel => worse fraction payload/propulsion.
Think of it this way (not truely math correct): In order to go faster you need to throw out mass for a longer period of time. Fine you'll take the extra mass with you. But (and theres always a but) in order to accelerate the now slightly heavier rockect you need to take some extra mass for all the previous accelation!
Actually you can go anywhere without to much fuel, it's a question of time.
But, even with the speed of light we're going really slow (years and hundres of them to anything outside our solar system).
What we really need is a new kind of physics!
Thomas S. Iversen
Disclaimer: IANAS (I am not a scientist)
:)
While covering that distance in only two weeks would seem to mean you'd have to go very fast (true), humans can go very fast too. It's the starting and stopping that'd kill them
Realisticly, you'd probably have to spend the first week accellerating, and the last week decelrating. On the 7th day after you'd left, you'd have reached max velocity, and then immediately take your foot off the gas and slam it on the breaks.
Anybody with any better knowledge of the actual distance needed to travel care to compute this?
Akardam Out
Americium and Neptunium should only be used for there god-given purpose. Cool little mini-nukes!
It is a waste of our precious scientists time trying to speed travel to Mars. First we must have popcan sized mini-nukes, then we can move on to such ungainly pursuits as space exploitation.
I say start pouring money into new launch systems and bring down the cost of putting things into Earth orbit. Once orbital access is cheap and readily available... maybe have a moonbase or three established... then interplanetary travel research will do us a lot more good.
Looks like sciencedaily is down for the count.
Please mod me up. My grandma might not make it to the weekend and she always wanted me to hit karma cap.