Please create an account to participate in the Slashdot moderation system

 


Forgot your password?
Close
typodupeerror
×
Space Science

Venus Probe Mission Approved by Steering Committee 13

Posted by Hemos from the lost-in-time-lost-in-space dept.
Anonymous Coward writes "Though often referred to as Earth's sister planet in terms of size and mass, Venus is now a totally different planet from Earth. Its temperature is high at 470C and atmospheric pressure at 100, and besides it has the characteristic atmosphere revolving at a very high speed (super rotation) and thick sulfuric acid clouds. Wrapping itself in an aura of mystery, Venus twinkles in the sky enticingly. At the Steering Committee for Space Science meeting held on May 10, the Venus probe mission was approved as an official ISAS project. http://www.isas.ac.jp/e/new/release/2001/06_03.htm l"
This discussion has been archived. No new comments can be posted.

Venus Probe Mission Approved by Steering Committee More

Venus Probe Mission Approved by Steering Committee

Comments Filter:
  • It's about time we did more with Venus. Of all the planets in the solar system, it's the most like earth (has a dense atmosphere, about the same mass, etc). IMHO it is a better place to terraform than mars, as there's plenty of sunlight for plants, etc, and it's mostly a matter of getting rid of greenhouse gasses (tiny floating plants may be able to help immensly with this). I hope to see the study of this strange and beautiful world continue.
    Of course I'm a little biased in that I work for the Jet Propulsion Lab and I like to see any space exploration, but this in particular is important to me.

    • ->Of course I'm a little biased in that I work for the Jet Propulsion Lab and I like to see any space exploration, but this in particular is important to me.
      Well, I don't work for JPL, and I still want to see the study of Venus, or any other body in space, continue.

      I feel that space has been neglected to much.

      Terraforming Venus should be plausible, but where should we go with all the CO2 ?

      • Re:About time (Score:3, Interesting)

        by QuantumFTL ( 197300 )
        Biomass. CO2 is converted, along with nitrogen and water, into biomass by plants. Thus, floating plants can thrive in a CO2 rich atmosphere.

        That's why the terraforming wouldn't be so darn hard, you already have the plant food right there! You just gotta engineer and release 'em. I mean, I'm not saying it's EASY, but things about planets that are nearly impossible to change, like mass, venus has. Of course, it's rotational period of 243 earth days would suck for colonists, but if you've already gone through all the trouble to terraform a planet, you probably have the resources to create something to simulate the night/day change, such as giant strips of metal orbiting venus, etc.

        There's no doubt that it would take hundreds of years to fully terraform venus, however most of the work could be done by biological agents rather than manmade machines, which should help signifigantly, and the final effect should be much better than what one can obtain with Mars.
        • Whoa, there. Sure, Venus has not more CO2 overall than Earth does. But Venus is almost completely lacking in water. Not in the air, on the ground or in the rocks (to such a degree that the rocks behave differently than Earth's). You'll need to import a planets' worth of water to Venus if you ever want to terraform it. And you have to keep that water around while you're trying to remove the CO2 from the atmosphere, which will be quite tricky. (The water tends to evaporate, travel high into the atmosphere, dissociate and the hydrogen escapes.)



          To make matters worse, Venus is still too close to the Sun to be habitable without artifical tending of the climate (something I don't know how to do, do you?). Venus was probably too close 4 billion years ago, and the Sun has only gotten brighter since then.



          Finally, how are you going to get the plants down there so that they can survive long enough to make a shred of difference? Venus surface is at 700+K. Roll that around for a moment. Remember, Earth's hottest is around 300 K. No organic tisses can survive at that temperature, not even the hyperthermophiles found near subsurface vents (that no organisms get close enough to the vents to feel this kind of heat indicates that there is a serious problem here). Bioligists estimate that at above 420 K or so, live simply cannot exist. After all, Vega I and II didn't last more than an hour each when they landed on Venus, and they were metallic constructs, not tissue.

          • Finally, how are you going to get the plants down there so that they can survive long enough to make a shred of difference?

            That's why I suggested *FLOATING* plants, as in plants that ride up in the UPPER atmosphere which is by far much much cooler (like the earth's stratusphere). I'm talking about tiny monocellular organisms, basically a specially engineered type of extremophiles.

            I am not suggesting doing *ANYTHING* signifigant to the surface until we have the atmosphere under control.

            You do have a point with the water. It's been a while since I took Solar System Astronomy, so I had forgotten that there was little water left in the atmosphere (So much of what I hear about venus was about it's runaway greenhouse effect, etc, which talked about PAST water). I managed to find a very interesting comparison [nasa.gov] between two theories that explain the dissapearance of water.

            I'm not suggesting we can turn Venus into a completely terran-like world in the next few hundred years, however it should be quite possible with a mixture of bio- and nano-technology to reduce the surface temperatures to a level where building large domed structures and underground settlements becomes feasable and even inexpensive when mass produced. There's still plenty of metals and carbon and oxygen, etc, around for biomass, even if it's rather short on hydrogen. At very least, we should be able to remove the carbon mostly from the atmosphere, leaving an oxygen-nitrogen atmosphere that can help make Venus more like earth.

            To make matters worse, Venus is still too close to the Sun to be habitable without artifical tending of the climate (something I don't know how to do, do you?).

            I may not be a planetary engineer, however it's very simple to see that blocking out the sun is a very practical solution, and is constantly used in science-fiction novels because it's very believable. Take an asteroid, roughly spherical, about 10 km in radius. Now lets say this asteroid is one of the iron-rich asteroids which is a minor, but signifigant portion of the asteroid population. Because the volume of this asteroid is roughly 4X10^15 km^3, a sheet of iron could be made at a thickness of 1 mm to be 64 MILLION km X 64 MILLION km in size. That's half of it's orbital radius! This is by far overkill, when all one really needs is a set of orbital night-day strips around venus, and a set of much smaller "obscuring" strips that cast vertical bars over the sun so as to dampen it's overall luminousity as measured by the venusian surface. Would this be a big project? Sure! But there's nothing in the laws of physics that says it couldn't be done, and the materials for it are already in space (large nuclear propulsion would be necessary to position them, or perhaps large solar sails). Of course one could always detonate nuclear devices inside the venusian surface to kick up enough dust to cool the planet rapidly as well, allowing a hundred years or so for it to settle.

            These ideas are very far out. But the whole idea of reshaping another planet is far out too. So is the idea of going to another planet! But if it's one thing that mankind has learned, often it's physics and human imagination that are the limit. Physics says yes, and human imagination has already gone there.

            But I'm still just a student, what do I know? :)
            • How are you going to keep the Sun-blocker between the Sun and Venus? It will want to orbit Venus. If you park , it'll only block sunlight over part of the surface, leading to cold regions and warm regions on the day side, not comfortable temperatures. Also, how are you going to keep it together? Between sheer and tidal stresses and constant bombardment, it'll need to be tough.



              A couple other points: you lock up the CO2. How do you replenish it? Earth's carbon cycle operates nicely because of our plate tectonics. Venus's total lack of water in the rocks stops plate tectonics. And don't forget that a Venusian day is 244 Earth days. That'll wreck havoc with any caridian rhythms, not to mention making daytime really hot and nighttime very cold.



              Surely you can imagine insanely advanced technology to terraform Venus, but it's centuries or more off. As much as I think Mars is really tough to terraform, it's much easier than Venus. The Moon would actually probably be easier.

              • Remember, the amount of metal we are dealing with is such that we could make a sheet 65 million km by 65 million km. That means that we don't need *ONE* sheet to do this, but rather we can have *MANY* smaller sheets. One idea is to put one in the orbit that takes 24 hours. It would be designed to be the right size such that at that distance it blocked out the sun to most (if not all) of venus. With the size we are talking about (half the size of the orbital radius at maximum!) its' not hard to have something this big. It'd end up being perhaps several times the surface area of the "day side" of the planet. I do not belive this sort of "Macro Engineering" is more than perhaps 200 years away, and is very feasible as it would not involve any new physics, merely some new engineering.

                Also, how are you going to keep it together? Between sheer and tidal stresses and constant bombardment, it'll need to be tough.

                Tiny meteors hit this thing, so what? Little holes will make almost no difference in the effectiveness of it, and the damage should be fairly localized as it would be weak enough that small sections would simply tear off. If larger sections are damaged, robotic space craft can mend it without too much trouble. Also, if I remember my astrophysics correctly, tidal forces act in the direction parallel to the line between the two objects. This would be perpendicular to the tangent plane of the "sun blocker" at any given point, roughly. Tidal effects affect the moon because the earth's gravity pulls the closer side of the moon more than the far side, thus trying to rip it apart. Indeed, if it was inside the Roche limit of Earth, it would become a ring or simply a large mess as tidal forces sheered it apart. Because the difference in the gravitational strength of venus on the side of the sun blocker facing the sun will be the same as the other side (it's a millimeter away for goodness sakes!) that becomes a nil point. Of course shearing forces are mostly the result of what shape the blocker ends up being (if it's made up of many small segments flying in constellation, this may not be an issue. no reason an ion drive on each segment that's solar powered couldn't keep it where it's supposed to be).

                It's also possible that nuclear devices or large asteroid impacts could be used to cool off venus and distribute its temperature equally enough that vast underground dwellings would be feasible. This way you have the right gravity, atmosphere, etc, all contained and just like on earth (if only underground), something you cannot do on the moon.

                I'm trying to keep to technologies that are envisionable at this point. The moon can only be terraformed so much, because of it's mass. It will *NEVER* be like living on earth, unless we somehow create an artificial gravity field. Same with Mars. But Venus, in the long run at least, has the best potential on really being like life on earth. It may take bombarding it with comets to bring water, assaulting it with genetically engineered organisms and nuclear devices, and large space-based mirror/blockers, but if mankind really wants Venus to be another home, at least to buildings made of metal if not to forests and oceans deep, then it shall be so.

                • But with all the miracle technology you are positing to do all of this, you might as well assume that we can develop artifical gravity for the Moon (Mars has about half the graviational acceleration of Earth, which isn't bad). For that matter, give your maxim of "if mankind wants it, it shall be so," we might as well figure we'll figure out a faster than light drive and we won't need to muck with Venus given that there are likely other planets well within their habitable zones. Unfortuantely, predictions for technology have a habit of not panning out. I'm still waiting for my hover car, it being 2001 and all.
                  • But with all the miracle technology you are positing to do all of this, you might as well assume that we can develop artifical gravity for the Moon

                    You missed the point. Artificial gravity is not forseeable using any widely held view of physics at this point. There are no highly respected physicists that I am aware of that have proposed a reasonable (if difficult) way of producing gravity. However, large quantities of TIN FOIL (which is basically what I am suggesting) are produced each year. I'm simply talking about scaling up existing technologies to make much bigger things. How would one do this? Simple: lots of robots. Right now robots suck. they can make cars, they can pretend to be a dog, but they cannot really do all the nifty things a human worker can do. This will change in the future (it might be 100 years before robots can replace all kinds of manual labor, but it will happen). And once we have robots that can mine and refine resources and use them to replicate, we will have a very powerful manufactoring technology which will allow us to make gigantic creations not currently feasible with human workers.

                    The technologies needed to do what I proposed are:
                    1. Making really big sheets of metal in space. Right now we can make little sheets of metal. All you need is a lot of robots workign together, and lots of energy (fission, fusion, solar?) to fuel the process.
                    2. Nuclear devices. We have about 20000 between the US and russia. I'm sure we can make better ones in a hundred years.
                    3. Genetically engineered monocellular life forms. Got that. We just have to make them better, that's all. 100 years of biotech development, and we'll have something working.
                    4. Ion drive. Got that. A recent Deep Space probe just proved that it's feasable, and actually rather simple. Should be dime-a-dozen in 100 years.
                    5. Nuclear drive. Got that. Working on making it better. Have had it for what, 25 years?
                    None of this technology is "miracle technology." Miracle technologies do what we would currently think is impossible, like artificial gravity.
                    Nothing I'm talking about doing has any real reason to be impossible, in fact most of it's possible today, it's simply very very expensive! (we could make that shield without too much trouble, provided that was where all surplus money was spent). So my motto isn't that "anything is possible" but rather "anything possible we can do if we chose too, given enough time, energy, and matter".
                    • 1. Really big sheets of metal? No, we can't make that now. We're decades or centuries from being able to move an asteroid into place, refining it and being able to shape it.

                      2. Try to get permission to use them, even on Venus.

                      3. We can poke around genetically, but we have very little control. You're proposing totally reworking an organism on a scale that's totally beyond what we can reasonably envision today.

                      4. True. We also have chemical rockets. Neither will be enough to move an asteroid from 3 AU to 0.7 AU with anything like a reasonable cost.

                      5. Where are you finding this "nuclear drive"? In as much as treaties ban nukes in space, I have to say that this surprises me.



                      Your problem is that your assumptions are science fiction. Grounded loosely in today's science, yes. But so is Star Trek. Your blithe complete optimism is the same as what we see in Zubrin and the Mars society: the idea that technology and science will advance as quickly as they would like for their pet project, and exactly along the lines that they would like. As I've said, it isn't necessarily so. You fail to grasp the scale and the difficulty of this undertaking, calling up technology you optimismically think ought to exist in 100 years.



                      If we ever get to where we can terraform Venus, so be it. I encourage you to write science fiction stories based on the concept of how you'd do it. But right now, any such predictions are silly.

                    • Really big sheets of metal? No, we can't make that now.

                      According to this site [envirosystemsinc.com] we throw away 350000 tons of aluminum foil every year. That's a lot of foil. Check out what the area of one roll is compared to how much it weighs. Now tell me that we cannot weld smaller, easier produced pieces together. Tell me that we cannot have thousands of robots doing this welding at inexpensive prices in a hundred years (they can already do this now, but they are not super cheap, they aren't mass produced).

                      So we can make really big sheets of metal now with existing technology. It's just rather expensive, that's all.

                      Try to get permission to use them, even on Venus.

                      I intentionally ignored this aspect. My fundamental assumption was that humankind would have to actually *WANT* to do this and focus on it somewhat to be able to accomplish this. This is merely a political problem. Also, china wants to use nuclear devices to help build a dam [tibet.ca] to generate hydroelectic power. If they can do it, we can do it on another planet.

                      We can poke around genetically, but we have very little control. You're proposing totally reworking an organism on a scale that's totally beyond what we can reasonably envision today.

                      True, our current biotech is *NOT* very good, however it's the fastest growing field of science and technology, and developments in nanofabrication, femtosecond pulse lasers, atomic force microscopes, and nanotubules has been giving us a much finer control in the realms of biomolecules and DNA. Biotech will most likely be the science where all the action is in the next century, as bioinformatics is slowly coming into the light, and our manipulation technology is growing by leaps and bounds (they are working on ways of reading the entire genetic code of a cell from a single copy of the DNA). What I proposed to do with the microorganisms may actually mostly be a "simple" matter of combining traits from different microrganisms, with the modifications necessary to make the genes compatable. This is very different from designing the organism from scratch, and I can forsee this within the next 100 years (we can already cross-transplant genes between species, look at the mouse that grew a human ear).

                      Where are you finding this "nuclear drive"? In as much as treaties ban nukes in space, I have to say that this surprises me.

                      I'm not sure where you have been, but NASA had developed this stuff in the 60s and early 70s. [wisc.edu] I believe they had some working prototypes even, however they were not allowed to fly these for political reasons (*sigh*). Also, NASA has been renewing its work in nuclear propulsion. [nasa.gov] A friend of mine received two PhDs from MIT, and one of his graduate thesises was on Nuclear Propulsion Using Magnetohydrodynamic Vorteces for Containment and Propulsion. So there's plenty of work going on with nulcear drives, in fact had we not stopped in the 70s, we could be using them for all sorts of things right now.

                      Also one other idea being pursued is the idea of an antimatter-fusion hybrid drive, using antiprotons to spark fusion reactions. This is being developed currently at Penn State University, and was the subject of my younger brother's science project a few years ago. NASA moved the site about it, so I couldn't find it for you.

                      We also have chemical rockets. Neither will be enough to move an asteroid from 3 AU to 0.7 AU with anything like a reasonable cost.

                      Chemical rockets are not worth mentioning here, as they lack the necessary specific impulse. Ion engines could do this, but they would take a very very long time. The actual moving process could take 30 years, in which case things like solar sails and nuclear propulsion become rather viable. Also, if we use a near-earth asteroid, it would only be 1 AU to .7 AU, a much smaller distance, and we may even be able to bring it close enough to earth to give it a "reverse gravitational slingshot" in which kinetic energy is transferred to EARTH rather than to the asteroid, thus saving us most of the work with our rockets. It's okay if moving the asteroid has a very high cost ($1 Trillon) in that if you can get 1 billion people to eventually live on Venus, that's only $1000 per person. Not too bad...

                      Grounded loosely in today's science, yes. But so is Star Trek.

                      Are you KIDDING?!?!?! Star Trek blatantly violates both relativity and quantum theory (warp drive and transporters, respectively) not to mention constantly gets their technobabble wrong (no, you cannot use ejected antimatter to create an electrolytic reaction to cause a space monster that ate your ship to throw up, like that one episode of voyager). Anything remotely scientific in Star Trek is nothing more than a plot device (I used to be and still am a big fan of TNG, but the more physics I take, the more I see is wrong with it, especially any time they do time travel). *ONCE* in a while they get something right.

                      What I am saying is *NOT* loosely based on science, it's actually possible today (granted current technology would require an amount of time and energy that would make it nonfeasible, and yes the biotech part isn't yet possible). Going to the moon was once science fiction, and there was nothing in the laws of physics to say it couldn't be done, but the physics said that the amount of energy required to do it was enormous. So it took a while until we learned to do it. It's the same way with this. It's just a matter of time/energy put into it. Eventually construction techniques, energy sources, robotics and biotechnology should be able to tackle all of these problems, as solutions can already be envisioned and planned today.

                      I'm not talking about doing this in 50 years. I'm talking about starting it in 100, and it possibly taking several hundred to finish. Few can argue that it's impossible, though. Politically infeasible? Maybe. Expensive? Perhaps, depends on whether or not we have self-replicating robotics and inexpensive intra-system travel. Those last two, may for now be science fiction, true. For now.

                    • It is not possible today, sorry. You need to review your basic studies of materials, for starters. Start with Galileo's discussion in "Two New Sciences" about what happens as you increase the sizes of things. You also need to review your celestial mechanics and your ion drive specs. It would take more than a few decades to move a decent-sized asteroid to Venus. We do NOT have the robots that can do this kind of machining. We do not have the biotech to do what you blindly assume your miracle organisms can do (do you know how little of the Earth's CO2 is in biological sinks? Venus lacks other sinks, so you're looking at vastly exceeding Earth's biosphere in mass alone by factors of, I believe, 10's). Antimatter? Don't be absurd. We're nowhere CLOSE to thinking about handling the stuff in any quantity, let alone using it. NASA funds a handful of projects that they don't expecto to bear fruit, but are interesting on the off-chance that they might (they also fund faster-than-light research, for instance).



                      Give it up. Venus is no where near within reach for terraforming right now. Why not be happy with exploring it?

Slashdot Top Deals

/earth: file system full.

Close