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Without the ISS, could the USA with partners (esa,Japan)
have built and sent a complete solar system plantetary expedition by now?
Here are the mission specs:
Duration of mission: 10 years
Primary Propulsion: Lox
Primary Power: nuclear
Vehicle: something like the 2010 film (soviet vehicle)
(its a normal ship with rotating crew habitation modules)
Crew Size: 12
Mission Operations: Main vehicle does not enter orbit of
target planets, Smaller vehicles go ahead of main ship
to explore and later rejoins main ship.
Targets: Planets,(or indicated moons)
Venus: crazy, but a short duration landing should be possible.
Mercury: crazier, because of fuel constraints. Would probably
have to pre-launch this landing module separately and rendezvous with it due to Fuel tank mass.
Again a very short duration mission. Main ship would not come closer to sun than a Venus orbit
Why go to the above Hell holes. Because humans like to do stupid showy things, and being first.
Mars : Three weeks
Jovian system Three Weeks. (G,C,E,)
Saturn System Three Weeks. (T,En,Ia)
Uranian system Three Weeks (M,U,T.)
Neptuninan system Three Weeks (T,N)
Pluto-Charon 4 Weeks
Return: maximum power for quickest Return to Earth Use
separate module for Aerobraking return of crew.
And whoever is left after these adventures will be as much a
hero as a certain Greek who sailed for the Golden Fleece
Note: dehydrated footstuffs, for 12 crew for 10 years takes
up 20x20x20 Sq Feet of space. I know High-Energy particles would among the Biggest hazzards of this type mission. But
let me see your design a Space suit for landing on Venus.
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No offense, but the mission you outlined I think is undoable.
What you've outlined would take four or five separate manned missions.
Minimum.
And the stay times for a manned mission are unrealistically low given all the effort to get there.
The stay times at all the outer planets and Mars should be something like a year or more.
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Whoa there... that is a really, really tall order to pull off.
I would say that manned expeditions to Jupter, and perhaps Saturn, could be pulled off with only a modest increase in technology... but you can forget Venus, Pluto, or the Icey Giants.
"Nuclear" is a very broad term for propulsion... do you mean solid-core NTR, gas-core NTR, salt-water NTR, gas-core VASIMR, solid-core Ion, gas-core Ion, or even the Orion engine?
Each mission would have to be sent from Earth individually though I imagine, if for no other reason that the ship couldn't handle it without a critical failure.
Refueling at the destination would also be vital if you were going to be doing multiple landings.
Spending so little time in each system doesn't make much sense either, you could hardly set foot on half the bodies in the Jovian system in that length of time, much less explore them.
[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]
[i]The glass is at 50% of capacity[/i]
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I admit that Going to Venus and Mercury would be the toughest part of the Mission. The cold of the icey worlds
would not be so scary. Not as scary as being stuck with the same
people for 10 years.
I am not advocating Nuclear Propulsion.
I am advocating a nuclear Power source.
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Well then, if you insist on using chemical propellants for your trip, then it is clearly impossible. Without nuclear propulsion, there will be no way any ship of reasonable size could be built, since the amount of fuel you need increases geometricly the faster you need to go. If you are stuck with chemical engines, you couldn't even get to Jupiter in ten years with a practical ship, much less explore it or get back home.
The Icey Giants aren't scarry because they are cold, they are scarry because they are so far away. The further out they are, the faster you will need to go to get there in a reasonable time frame (4 years one way for your mission w/ margin), and so the more and more fuel you would need. You would require so much fuel infact, that without a Fusion drive, I don't think that even a Fission engine of any sort would get there fast enough.
[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]
[i]The glass is at 50% of capacity[/i]
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You are right a Ten Year Mission is Unrealistic. Fifteen sounds
better. Incidentally I used to have Space Shuttle Simulator,
and one of the Fun things you could do with it is Go To Mars.
I know, Life support and all of that, but with four Full power mock ups. (ie the power of the Launch configurations).
it was possible to get to Mars and Back in 2.5 years. Now Albeit I would Refresh the Vehicle en Route (computer Trick) meaning I did not have go carry those extra 3 ET's and 6 Srb's
with me(I know the Srb's are not for space, change them to liquids). If you plan out your Fuel Logistics correctly you do not have to carry all the Fuel with you. You can
rendezvous with them fuel tankers en route.
I don't believe it's impossible logistically given the right
plantetary alignments
I do believe the biggest dangers are HUMAN FACTORS.
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The Shuttle Sim's computer trick bascially provides you with unlimited rocket fuel... The number and size of tankers you would need is completly unacceptable, we are talking thousands and perhaps tens of thousands of tonnes of fuel here.
[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]
[i]The glass is at 50% of capacity[/i]
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let me see your design a Space suit for landing on Venus.
*Gee, I'd love to oblige you, but I'm not a spacesuit designer -- and especially not under those conditions -- by a long shot.
Humans on Venus. It's a staggering concept. I was surprised when Arthur C. Clarke, in one of his sequels to "2001: A Space Odyssey," had humans on Venus. A small base, IIRC -- happily engaging the struggles to survive there.
Would be an accomplishment to behold, all things considered (Venus' atmosphere, etc.).
--Cindy
We all know [i]those[/i] Venusians: Doing their hair in shock waves, smoking electrical coronas, wearing Van Allen belts and resting their tiny elbows on a Geiger counter...
--John Sladek (The New Apocrypha)
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A trip to Venus is probobly beyond our technology right now...
Imagine a trip to the bottom of the ocean, like where the Alvin deep-submurgance submarines go... the windows must be six inches thick, the pressure vessel sphereical to maximize strength, and if there was the slightest leak - the tinyest pinhole or crack- BAM!
The surface of Venus is much like this... the "air" is so dense, that it is almost a liquid. It would resist your motion much like water would in a diving suit. If not for the heat, it probobly would condense to a sea of CO2... and if there was a leak... the same thing would happen as on Earth.
And it gets worse, much worse...
The never-ending heat, all over the globe from pole to pole, is the hottest of any known solid body in the universe. Venus, despite the clouds, is probobly never dark... the parched rocks themselves would glow a dull red from the heat... Not only is the atmosphere so incredibly thick, but it is incredibly hot too... Hot enough to liquify sulfur and even aluminum metal, hot enough to weaken steel and other materials, hot enough to destroy anything not actively cooled.
And active cooling is a problem too... in order to push the heat out from your base, you will either need a cooling system of massive proportions, since the thick air would carry heat easily. And it gets better too, a nuclear reactor relies on the ability to dump heat away from the core, but where? The atmosphere is so hot, that you couldn't efficently cool the reactor, so the turbines would be hard to spin. The same problem if you are trying to make a supply of coolant, that to cool it the heat has to go someplace. Getting it down cold enough for humans to withstand it would be extremely difficult.
And then you get to worry about the corrosive effects of the sulfuric acid clouds, which would eat most anything not made of stainless steel or specially protected.
Packing all this into a suit is well beyond our technology I imagine... even getting a suit to resist the pressure and corrosive effects would probobly be a little beyond us, and the only practical cooling would be a huge backpack tank full of liquid helium or hydrogen, since you would need a "cold" source below or equal to human body temperature to live. Pumping the ultracold fluid through channels with human flesh on one side and hundreds of degrees centigrade on the other would be a huge challenge.
And then you would probobly run out of coolant before you made it far out the airlock hatch.
The only sane Venus mission I can think of would be something like the one in Ben Bova's Venus, where bascially a "space blimp" would hover where the atmosphere was cooler and thinner, then lower a "bathyscape" to the surface, connected by a multi-kilometer cable that supplied cryogenic coolant and power. Return to space would be difficult given the "blimps" drag.
[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]
[i]The glass is at 50% of capacity[/i]
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*Hi GCN: I'm >this close< to saying it's probably impossible to ever have a human manned landing on Venus. But then I remember von Braun's comment: "I have learned
to use the word 'impossible' with the greatest caution."
If Clarke thinks it may be possible...(but then he's speculated there are trees on Mars currently :hm: )
--Cindy
We all know [i]those[/i] Venusians: Doing their hair in shock waves, smoking electrical coronas, wearing Van Allen belts and resting their tiny elbows on a Geiger counter...
--John Sladek (The New Apocrypha)
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Just a reminder only 1 person will orbit-decend-land on
Venus and Mercury, I think two people just creates more obstacles than it's worth.
If you design your lander correctly you should be able to
make a short duration landing, which is all i am
looking for. (It is after all a foolish a human Stunt). Essentially I think you have to
design your lander with its fuel tank surrounding practically the entire ship. The Tanks would
have pressure relief valves that are constantly purging and
yes WASTING landing fuel. This would results in very short 2 hr landing and short excursion of 1 hour. And one thing
your forget about the venus enviroment, it can be replicated on Earth, which is all clever engineers need to suceed.
I would be more worried about the Mercury Mission. I am
not sure You can Fall into a mercury orbit, orbit the planet and Break orbit and catch up with a mother ship without
at ship at least 3/4 the mass(inc. Fuel) of your mothership.
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I don't understand why you are worrying about Mercury. Mercury's a piece of cake compared to anything beyond Jupiter. The delta-vee to go to Mercury and back is higher than Mars or Venus; it's comparable to Jupiter but a bit less, I think. Travel times are reasonable; 100 days each way (faster than any other planet). Solar radiation will require shielding, but nothing we can't handle, and the closer you get to the sun, the more the sun's magnetic field protects you from cosmic rays. So from a radiation point of view, Mercury is not bad (especially with the fast transit time).
The Mercurian poles appear to have thick deposts of water ice in the permanently shaded aeras. Any technology developed to use ice in the lunar poles would work on Mercury as well, with minor modifications. I think Mercury's quite a good scientific destination for humans, and reasonably "habitable" as well. It is a dynamic world with a magnetic field (weaker than Earth's, but more than Mars). It may have active volcanism. By the end of the twenty-first century, we could have geologists drilling the Mercurian ice fields to recover the layers of water and volcanic gasses (like sulfur dioxide) that could tell us the history of Mercurian volcanism and impact events all the way back to the planet's origin. The world could even be rich in minerals (you'd export to earth using solar sailing cargo craft; the sunlight increases in the same portion as the solar gravity, so it's an effective transport medium for late 21st century cargo).
As for Venus, the best we can hope for a century or so is a manned station in Venus orbit, from which heat-hardened robots will be directed to explore the surface and solar-powered aircraft and balloons will be controled. Even retrieving small samples from the surface will be immensely difficult. Venus's gravity is about the same as the Earth's. The delta-v to go from the surface of Venus to Venus orbit is about the same as to enter Earth orbit. How in God's name would one land on Venus the equivalent of a FULLY FUELED SPACE SHUTTLE--even a small shuttle!--preserve it against the roasting heat and crushing pressure, then launch it back to orbit? I doubt such technology can be developed for a very long time.
I could see this scenario, though, IF we had the money:
1. Robotic aircraft fly in the atmosphere and short-lived battery-powered probes explore the surface briefly.
2. Robotic surface vehicles become longer-term and better able to deal with the conditions; perhaps they'd use RTG power sources. Solar powered aircraft or balloons become long-lived.
3. Venus sample return: a robotic probe lands and obtains samples; a Venus robotic aircraft sends down a little, battery powered, heat-hardened aircraft to retrieve the sample and bring it to the mother aircraft; the mother aircraft using solar power extracts water and CO2 from the Venus atmosphere very diligently over a year or two (water is very rare, parts per million) and fuels a small rocket (total mass, mostly fuel from Venus atmosphere, 3-4 tonnes); then the sample is flown to orbit by the little rocket, retrived by an orbiting vehicle, and flown to Earth, probably by using ion engines.
4. Robotic surface vehicle and support aircraft become so sophisticated and capable that real-time coordination from Venus-orbit becomes practical and useful, and technology for support humans in orbit far from Earth becomes reliable. So a small base (4-8 people) in Venus orbit is established and the crew renewed every 19 months.
5. Eventually the technology to fly people to a high-altitude Venus aircraft or blimp and back to orbit might be developed. But it doesn't strike me as worth the money, because safety is a problem (who wants to fall into an oven?) and the energy for the return trip is enormous.
6. Humans to the surface of Venus? Dream on! Why? It'd be easier to develop virtual-reality capable robots that can handle the heat and pressure. In Venus orbit you'd sit in a special chair, wear a special helmet, and "walk around" on Venus. Much cheaper, easier, and safer.
-- RobS
P.S: Note about surface conditions: surface pressure, 94 times earth normal (=1400 lbs/square inch!); temperature, about 750 F (450 Centigrade). Yes, there are mountains, tall ones. No, they aren't much better.
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I am willing to entertain the possibility that humans might land on Venus, in a carefully constructed but cramped lander, probobly with two seats... Heavily armored and insulated, it would operate under battery or internal fuel cell power, since they require no temperature or pressure gradient to operate. It would have to have active cooling, probobly bottled cryogenic fluid (liquid hydrogen perhaps, extremely high specific heat) pumped through channels in the mirror-finish (ceramic?) insulation.
It would need an extremely fault-tollerant propulsion system, probobly a pair of solid rockets cooled by the cooling system, where the decent engine would't have enough thrust to stay airborn so you would decend slowly and stay on the ground even with the engine running, no throttling. Firing the acent engine would get you back off the ground, or eject the cryogenic coolant ballast to abort decent. At altitude, a balloon would be inflated and everything unessesarry cut loose for recovery.
The thing I am worried about would be that the pressure would be so high, that you wouldn't get much thrust at ground level.
Since you would need a "space blimp" to recover the thing, you might as well just lower it on a cable anyway.
But having a man in a self-contained suit stand on the surface and pick up rocks? Uh uh, isn't going to happen.
RTGs wouldn't work either, since they have to have a temperature gradient to work. Nuclear reactors would have trouble too for the same reason... There is just no way to power a Venutian surface vehicle, which is just as well, since the heat would kill it anyway. The electrical resistance in the wires of the drive motors, the semiconductor electronics, the communications antenna wiring... all fried pretty quickly.
[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]
[i]The glass is at 50% of capacity[/i]
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This type of mission would be about crew quality. A crew
that has the equipment and knowhow to repair, service, adjust
any component of your Mission elements will at the very least
keep themselves from becoming mummified remains.
There being so much time in transit, the crew should in addition to their Main Duties be able to perform TWO of the following duties
1) Disassemble/repair Ship engines. (Ship uses 16)
2) Dissasemble/Repair life support equipment
3) Medic duty, plus able to do non-trivial surgery.
4) Pilot any ship/lander
We could assemble a crew like this today, question is would any of them want to spend 15 years in space.
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Arranging the mission so that you could fix any serious system problem is impractical, some things just can't be easily worked on in space, and the tall order of spare parts would add too much mass.
You literally might as well launch two ships to the same destination, each with half a maximum crew.
I have doubts that any crew could mentally survive fifteen years in space.
[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]
[i]The glass is at 50% of capacity[/i]
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6. Humans to the surface of Venus? Dream on! Why? It'd be easier to develop virtual-reality capable robots that can handle the heat and pressure. In Venus orbit you'd sit in a special chair, wear a special helmet, and "walk around" on Venus. Much cheaper, easier, and safer.
-- RobS
*Well...I see your point. But then someone else might ask, "Why have humans in orbit around Venus even? Do the virtual reality bit while seated on Earth." Transmission lag would have be factored in, but...
I understand the desire to actually physically explore different worlds. But I certainly doubt Venus will be one of them.
IMO, a worthwhile manned mission would involve more than just a brief (less than a day) one- to two-party affair. Otherwise it does seem more like a stunt than a mission. And for the risks involved, not to mention the costs...
Actually I'd like to see someone successfully pull off creating a robot to withstand the heat and pressure of Venus for just 1 day's worth of travel/exploration alone (but more would be great of course).
--Cindy
We all know [i]those[/i] Venusians: Doing their hair in shock waves, smoking electrical coronas, wearing Van Allen belts and resting their tiny elbows on a Geiger counter...
--John Sladek (The New Apocrypha)
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Even building a robot to survive on Venus will be a severe challenge. We have metals that will work at those temperatures, but we don't have power sources or electronics. Remember that electrical conductivity and resistance change with temperature, and computers depend on those two things. And if RTGs don't work, could we beam microwave energy down, through the pea soup atmosphere?
-- RobS
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