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Ion Rocket to Map Moon with X-Rays
jralls writes "The Guardian is reporting that a European ion-rocket has taken the last year to reach the moon and is about to enter lunar orbit. Once it slows and gets into a very low orbit, it will probe the surface with x-rays in an effort to solve the long standing puzzle of the moon's origin."
I wonder if we are able to observe this interplanetary tortoise from earth? If it passes the bright side in full moon, we should have quite a clear view of it since it's going so slowly.
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The dangers of knowledge trigger emotional distress in human beings.
I expected the story to read "But when Flash Gordon approaches, will the moon people fight back with their electro-guns? Watch next week to find out!"
From the article :
"The sun emits X-rays and these are reflected back into space by atoms on the Moon's surface. A magnesium atom will reflect an X-ray in a different way from an iron atom, and Grande's detector can detect these differences.
Flying over the lunar poles, so that it covers the entire Moon as it revolves below, Smart will create strip maps of the surface - and eventually a global map of its composition."
Look like useful data to me if we were in the 'mine the moon' business... maybe in a not so distant future?
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I keep hearing that Ion propulsion is faster than what we currently use. What's with the incredibly slow travel time?
unlike in the 60s and 70s, they are using ion engines for this mission, which can run of solar power.
they give less trust/second, but they can keep burning for allot longer, since the sun gives a constant supply of fuel (in the form of electricity from solar panels).
so you've got a smaller probe, which means easier to get into orbit from where it can fly on it's own power, so even tho it takes longer to get where you want, it will be cheaper to get it into orbit.
btw, they are planning on bigger engines in the future, so hopefully they will go faster someday.
All indicators show that the human race is selectively breeding itself for stupidity.
Anyone still using film up there is going to be pissed when their exposures are ruined.
Everyone learns that the moon is made of cheese in the cartoons. I bet they'll say it's from Wisconsin.
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Will these guys be able to snag some good shots of the trash we left on the moon? Exluding the flag of course, which can't be trash cuz its on a stick.
Jeoin
"Come to the moon and smell our dairy air!"
Doesn't quite have the same ring...
Isn't that the way the monolith will be found?
sobering thought that that headline sounds exactly like something you might hear in a pulp sci-fi movie from the 50's...
pr0n - keeping monitor glass spotless since 1981.
In all seriousness it's nice to see some other serious large-scale attempts being made by countries other than the US and Russia. As with all things scientific, the more head working together the more we all learn.
The tradeoff is betwen the extra time it takes to get to the destination (due to the low thrust of an ion engine), and the reduced cost created by being able to launch a much smaller amount of mass into space in order to do the mission.
btw, they are planning on bigger engines in the future, so hopefully they will go faster someday.
The issue with ion enginer thrust is not so much size, as it is power. The thrust you get is directly proportional to the amount of power you can generate. If you're using solar arrays, then you're limited to something between 15-20 kW (the Boeing 702 has solar arrays that produce ~15 kW at end-of-life).
Doesn't this mean earth should have some huge dent in it, and not be so round? Look at the sizes of Mars and Earth. Are you surprised earth is still here after a crash of that magnitude? I am. Maybe earth was a lot bigger before a Mars-like planet destroyed itself crashing into earth, but then I go back to my question about the roundness of the earth.
Maybe someone more knowledgeable wants to talk about that. The article doesn't go into any great detail on that, which causes a lot of questions to be raised.
Free X-rays for all Moon residents. Take that Canada!
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that it is not the whole moon. There are areas that light, and x-rays do not reach. Sadly, that is the most inteesting as it may contain ice.
I prefer the "u" in honour as it seems to be missing these days.
....what happened when they probed Mars with X-rays! Watchout! (is Gary Sinise piloting?)
The mountains on Earth may appear huge to us insects on the surface, but from a distance the earth appears as smooth as a billiard ball.
Ironically this event was so big, that unlike latter smaller hits, all evidence in the way of dents will be gone as the entire globe virtually liquefied and coalesced again. Though I wouldn't rule out some exotic mass distributions that might lend evidence of it.
Letter To Iran
At each pole, there are such deep caverans that sun never reaches it. That includes X-rays and normal sun light. That is why it is possible for ice to be there. And yes, it is considered part of the surface.
SMART-1 has been making bigger and bigger orbits around the earth, because of the smaller thrust explained above. It goes faster and faster, and because the craft gets further from the earth, it becomes easier to get into a bigger orbit. So at first the orbits became larger very slowly, but the last months it has grown faster than ever before.
The last months the orbit was also synchronized with the moon. The highest part of SMART-1's orbit coincided with the lowest point of the moon's orbit. This helps the craft to get an extra boost every month. Take a look at a graph of the orbit here.
Oh, and they do have normal propellant onboard, there's some 70kg left iirc. I think it was installed in case the ion engine failed, but I'm not sure of that. It could also be to correct the initial orbit if the launcher would have placed it in a wrong one. Anyway I *hope* it will be used to attempt a soft landing after the mission is over.
"It's too bad that stupidity isn't painful." - Anton LaVey
Posted by CmdrTaco on 01:06 AM -- Monday November 08 2004
:-P
from the dept.
I've always read the 'from the so and so and whatever dept' cuz it's humourously funny and cynic at the same time.
This time, it's just plain ol' from the dept. I just wonder, whether it is an oversight or CmdrTaco really does not have anything witty to say about it?
I know, I know it is off-topic, mod me down then.. I probably deserve it.
Will sys-admin for food
Ion drive technology allows you to explore space in ways that chemical rockets simply can't.
Quoting from the article,
"We have shown that even a small ion engine like Smart's can get us across space. Now we are planning to build space telescopes and robot probes to planets such as Mercury, using bigger and more powerful ion engines. These will take years off space-travel times. Instead of decades-long missions, we will take only a couple of years to cross space for future projects."
But,
"Ion engines need electricity and only solar panels can provide enough at present. So ion engine missions will be restricted to planets and moons near the Sun."
So the solution to deep space exploration is nuclear-powered ion-drives and NASA is working on it.
Look up any reasonable book on mechanics and you will find a formula for the final velocity of rockets that have a empty mass M, mass of fuel m, and have an exhaust velocity v. The final velocity of the vehicle is ...
In other words ion rockets will beat chemical rockets because they eject their exhaust at a reasonable fraction of c, whereas chemical rockets have exhaust velocities more like velocities we see on earth (e.g. bullets). So chemical rockets need lots of mass, but that's ok because they throw out lots of mass. Trouble getting to space is expensive ... each kilo of fuel you put in orbit better be wisely used ... so in space ion rockets make sense (apart from the fact you can't use them on Earth anyway ... wouldn't be able to lift off even).
Hope this makes things a bit clearer.
Bitter and proud of it.
Recent speculation is that the very center has a high ratio of Uranium, enough so that the pressure actually creates a self-sustaining natural nuclear reactor. When it gets too hot it diffuses and shuts down, only to coalesce and restart again (never a big boom). This starting and stopping of the nuclear processes at the Earth's core may be responsible for our planets large magnetic field, and occasional shut downs and reversals of the magnetic field as this nuclear process fluctuates.
You're right that the center would be weightless, but under more pressure than we can possible create in the lab with the best diamond anvils. It only takes a few miles of crust to crush carbon to diamonds, and here we are talking 8,000 miles of rock pressing down. Though the rock (iron) at the center isn't adding any additional pressure, it has thousands of miles of rock above it that is. Quite the hellish place.
BTW, I don't know how I typed Biq in my rirst post when I meant to type Big (no one seems to have noticed)
Letter To Iran
It's fairly simple. The ESA doesn't have a rocket capable of putting a payload on a lunar path. AFAIK Arianne is really only good for LEO stuff. The only two countries with lunar capable rockets are I believe the Russians and the USA. Of course, the ultimate lunar capable rocket, the Saturn V, is dead, so all we can do is cross our fingers and hope that NASA will come to its senses and bring back the big dumb booster.
This is my sig.
Here is a link to a Discovery article
Nuclear Planet
Is there a five-mile-wide ball of hellaciously hot uranium seething at the center of the Earth?
Yes the core is mostly Iron, but it's not pure iron. I mentioned iron as a core material in my post.
Letter To Iran
It's really freaking big. Mercury and Venus don't have any moons, and the moons of Mars appear to be captured asteroids...relatively tiny rocks not big enough to form themselves into spheres. The Earth-Moon system is nearly a double planet. Of the inner planets, Earth is the only one with a decent moon...and it's a monster compared to the planet.
In any case, the planets you see now are just the ones that stayed in the system. Material didn't just cleanly accrete directly into the existing bodies. Most of the objects formed were kicked out of the system by interactions with other bodies, or were absorbed into other objects or the Sun itself. What you see is the final result of a great many collisions and near-miss interactions. (And the present orbits aren't truly stable, just stable enough not to worry about. I think the lifetime of the present orbits of the planets is greater than that of the sun itself. Maybe a little less for the Moon.)
The rings of the gas giants are likely far younger than the planets themselves, they are almost certainly not leftover material from the accretion. And they do have moons, lots of them...each giant has dozens, while the entire inner system has 3. However, even taken together, the moons and rings of each giant aren't much compared to the planet itself.