The inner solar system

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Yuri_Armstrong

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There's always a lot of talk about missions to the moon or mars, and now asteroids because of Obama's speech. But what about missions to Venus or Mercury? Obviously the conditions on these planets are a lot different than the moon or Mars. Do you think we will ever see manned missions there? Do you think we should send manned missions there as opposed to Mars? What type of technology and suits would be required for astronauts to survive the harsh conditions of these planets?
 
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sftommy

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Neither candidate planets offers much hope of future habitability in the near term, say a century or so...

There will be robotic study missions to both but until some planet-wide chemistry changes can be developed Venus has limited opportunities to provide for a self-supporting mission and limited benefits to secure ROI for commercial exploitation.

Mercury needs a science station on leeward side but again offers limited in situ resources for a self sustaining mission and little reward for commercial exploitation.
 
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Yuri_Armstrong

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Yeah, there's some tough obstacles to overcome. But lets take a look at the advantages of Venus:

-At about .90 of Earth's gravity, gravity related health issues are of little to no concern
-Closer to the Earth, which means a five month trip with current tech rather than 6 months for Mars
-More frequent launch windows very 584 days
-A thick atmosphere, no meteoroid damage to worry about

Now I know a lot of you are going to point out the ridiculously high pressure and temperature, so instead of setting up an outpost on the ground, it might be better to have the outpost situated in the Venusian atmosphere where the pressure is not much different from Earth's. The high temperature is a seperate problem of course, there are some really novel ideas about artificially cooling Venus' surface such as using sun shades.

For the time being all of that is not economically or technologically viable. Did the manned missions to the moon have a goal of long term colonization or mining? No, they went there for national pride and scientific research. The same could be done for a mission to Venus one day (but that will likely be sometime after we have outposts on the moon and mars).
 
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neutrino78x

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Yuri_Armstrong":1wtjmm7b said:
Yeah, there's some tough obstacles to overcome. But lets take a look at the advantages of Venus:

-At about .90 of Earth's gravity, gravity related health issues are of little to no concern
-Closer to the Earth, which means a five month trip with current tech rather than 6 months for Mars
-More frequent launch windows very 584 days
-A thick atmosphere, no meteoroid damage to worry about

Yeah, we've talked about that before in this forum. My whole issue with Venus is that you can't build new structures using resources in the atmosphere (at least not with current technology). With Mars, you can get to the surface now, and you can use the iron there to make steel and other materials needed to create structures.

Plus, to me, philosophically, I want to move away from the Sun, not closer to it. Going to Venus would be a step backward, to me. :)

--Brian
 
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Yuri_Armstrong

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neutrino78x":2rmnyg4f said:
Yuri_Armstrong":2rmnyg4f said:
Yeah, there's some tough obstacles to overcome. But lets take a look at the advantages of Venus:

-At about .90 of Earth's gravity, gravity related health issues are of little to no concern
-Closer to the Earth, which means a five month trip with current tech rather than 6 months for Mars
-More frequent launch windows very 584 days
-A thick atmosphere, no meteoroid damage to worry about

Yeah, we've talked about that before in this forum. My whole issue with Venus is that you can't build new structures using resources in the atmosphere (at least not with current technology). With Mars, you can get to the surface now, and you can use the iron there to make steel and other materials needed to create structures.

Plus, to me, philosophically, I want to move away from the Sun, not closer to it. Going to Venus would be a step backward, to me. :)

--Brian

Yes, but couldn't some resources be taken by machines from the surface? Obviously things like water will have to be shipped in. A Venus station would probably never be fully self-sufficient unless there was some major terra-forming.

I was just interested, as to what people would say in regards to Venus. There's constant discussion of the moon and mars but nothing really about Venus or Mercury.
 
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HopDavid

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Yuri_Armstrong":44i86p4a said:
it might be better to have the outpost situated in the Venusian atmosphere where the pressure is not much different from Earth's. The high temperature is a seperate problem of course,

At altitudes where the pressure's bearable, it is much cooler than on the surface. At a certain altitude, Venus is hospitable to humans in terms of pressure and temperature. But the gases are toxic.

Our breathable atmosphere is a lifting gas in Venus' atmosphere. Geoffrey Landis has written a lot about the possibility of balloon cities floating in the clouds of Venus.
 
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Astro_Robert

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In some ways the inner soloar system (Mercury & Venus) can be difficult to orbit. And interest in asteroids actually spawned a year ago as a result of the commision reccomendation, rather than just last week from Obama's speech.

As far as Mercury:
Just look at Messenger, and its contorted orbit. Yes you could go more directly at a cost of much more propellant, but it isn't all that economical. Also, consider that Mercury is in 3:2 resonance with the sun, so that every part of its surface falls on the sunlit side at some point, meaning a potential outpost would have to survive brutal radiation.

As far as Venus:
It might be interesting to do stuff in the atmosphere, but what is the fallback position? In the event of an emergency, like say we are experiencing on ISS, what do the astronauts do? On Mars one could concievably put an outpost partially underground to help with shielding as well as provide a safe harbor during emergency. Floating on a gigantic airship somehow makes me more nervous given that both are on different planets.

I am not a big fan of Asteroids myself, but they do offer a variety of different mission requirements. Personally I still like the Moon, but there are some asteroids that can be reached for comparable energy that the Moon can be, especially considering the Moon's gravity well is substantially more than any asteroid. Asteroids are small enough to explore quickly, but new enough to be worth some of the effort. If it helps to re-energize NASA then I can support it.

I just don't entirely trust that the Obama administration is proposing a real program, rather than just killing off something that George Bush started to spite him. I mean there has been talk of heavy launchers, but it seems to me that it is Congress insisting on funding for the proposed launcher, and the administration just using a back door to kill off Constellation (Enterprise was Constellation class, how can all the Trekkies sit back and take it, lol).
 
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neilsox

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Earth and Mars are tilted about 23 degrees with respect to the plain of their orbit but the tilt of Mercury is very close to zero. That means that sunlight never falls on the bottom of craters near the poles of Mercury. Human colonies in the bottom of these craters have constant temperatures of about minus 130 degrees c. That may be the easiest place to operate a human colony off Earth. About ten times the solar energy (compared to GEO orbit above Earth) is available at the rim of several of these craters 24/7/365, so mirrors can warm the crater and provide light as needed. Unless multiple sling shot maneuvers are performed the energy to make a soft landing on Mercury is several times the energy to land on Mars.
There are multiple threads about terraforming Venus and the possible colonies floating in the cloud tops. I also am concerned that a loss of buoyancy leads rather quickly to a horrible death. Escape pods are possible to take survivors to an outpost in low Venus orbit or another habitat floating in the cloud tops of Venus. Wind speeds are very high in the cloud tops of Venus, so the day night cycle would be about 4 days for the floating habitats. The severity of wind gusts is unknown. Neil
 
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HopDavid

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neilsox":21n5a3ok said:
Earth and Mars are tilted about 23 degrees with respect to the plain of their orbit but the tilt of Mercury is very close to zero. That means that sunlight never falls on the bottom of craters near the poles of Mercury. Human colonies in the bottom of these craters have constant temperatures of about minus 130 degrees c. That may be the easiest place to operate a human colony off Earth. About ten times the solar energy (compared to GEO orbit above Earth) is available at the rim of several of these craters 24/7/365, so mirrors can warm the crater and provide light as needed.

Sounds a lot like our moon's poles. And like our moon perhaps Mountains of Eternal Light as well as Pits of Eternal Night. But their mountains of eternal light get a lot more energy. This does sound like interesting real estate.

neilsox":21n5a3ok said:
Unless multiple sling shot maneuvers are performed the energy to make a soft landing on Mercury is several times the energy to land on Mars.
There are multiple threads about terraforming Venus and the possible colonies floating in the cloud tops. I also am concerned that a loss of buoyancy leads rather quickly to a horrible death. Escape pods are possible to take survivors to an outpost in low Venus orbit or another habitat floating in the cloud tops of Venus. Wind speeds are very high in the cloud tops of Venus, so the day night cycle would be about 4 days for the floating habitats. The severity of wind gusts is unknown. Neil

Yes, Mercury doesn't have an atmosphere for aerobraking. From LEO to Mercury's surface is about 16 km/sec (assuming a soft landing). That seems like a show stopper.

Hohmann trip time is .29 years or about 105 days. Launch windows every .32 years. Both those are nicer than Venus and Mars.
 
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halman

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Perhaps many of us will (or would be) surprised by what economics will dictate regarding the exploration of the Solar System. Mercury may be the most valuable place in the whole shebang, because it is likely to harbor large quantities of heavy metals. Digging in and getting under the surface will yield ore that can be processed and sold. The more habitat you carve out, the more ore you have.

Venus, on the other hand, looks to be the last place we will ever visit, because there is simply nothing there that we need right now. And living space is too plentiful to deal with the problems of trying to create an airborne culture in an atmosphere that is poisonous.
 
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scottb50

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halman said:
Perhaps many of us will (or would be) surprised by what economics will dictate regarding the exploration of the Solar System. Mercury may be the most valuable place in the whole shebang, because it is likely to harbor large quantities of heavy metals. Digging in and getting under the surface will yield ore that can be processed and sold. The more habitat you carve out, the more ore you have.

Getting there is simply taking enough propellant as long as you have a viable vehicle. The mechanics are proven, it's the hardware that's needed.
 
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