Why aren't we exploring Venus?

[destrekor]

Helios 2 was faster, it used gravity assist. Then there's Ion drives which have been improving.

Then consider Project Orion, http://en.wikipedia.org/wiki/Project_Orion_(nuclear_propulsion)

I just used the Voyager probes for reference. We are capable of faster crafts now, but none (aside from Helios 2) have been pushing long enough to build up higher speeds, quite possibly only because missions haven't called for such... they could well be capable of traveling faster if they followed the Voyager path.

I've been ecstatic about the recent Ion drive R&D.
And I seriously doubt we'll ever go about putting together an Orion-style craft. It would be awesome, but I doubt we'll see such.

We are definitely capable of faster speeds than I mentioned, but still - aside from brute-forcing it with an Orion-style craft (and it would take a long time to build up good speed, iirc), we're still far shy of reaching 0.01C.

Depending on how funding and different R&D projects go, propulsion systems could start making breakthroughs in the theoretical realm - seeing it realized, however, it could be awhile.
That's why I'm hopeful for the privatization of space: the quest for profits and "first dibs" - especially for tourism and mining revenue - could help speed things up sooner than I'd expect. We'll need such companies to build up a bit of profit before they can start chasing this goal, but I do have reluctant hope we might be able to achieve something again in terms of manned space exploration programs.

 

[destrekor]

Destrekor - I'm pretty sure that the Voyager probes are decelerating. The strongest gravitational influence on them right now is the Sun, and it's still trying to tug them back. They're moving faster than escape velocity, so they will eventually leave, but they've still got to fight the pull.

I do believe this is correct - but I didn't bother to research it further.
A 2005 article stated Voyager 1 was travelling at roughly 39000MPH. I did a conversion from NASA's page as of today, and it turned out to be roughly 37000MPH.
It would make sense, since it's in/near the heliosheath (outer edge) at the moment. I'm not sure if it's gravitational pull slowing it down, insomuch as increased pressure from the outer reaches and a slower solar wind.
Since it has breached escape velocity, at the edges of the "atmosphere" isn't the gravitational pull weaker than the craft has experienced up to that point?

Also, according to NASA's JPL page, it seems like they switched to the secondary thrusters to conserve the lifespan of the primaries - perhaps this is actually the biggest reason for the recent deceleration?

 

[disappoint]

Project Longshot:

http://en.wikipedia.org/wiki/Project_Longshot

Project Longshot was a conceptual design for an interstellar spacecraft, an unmanned probe intended to fly to and enter orbit around Alpha Centauri B, it would be powered there by nuclear pulse propulsion. Developed by the US Naval Academy and NASA from 1987 to 1988, Longshot was designed to be built at Space Station Freedom, the precursor to the existing International Space Station. Unlike the somewhat similar Project Daedalus, Longshot was designed solely using existing technology, although some development would have been required.
Unlike Daedalus' closed-cycle fusion engine, Longshot would use a long-lived nuclear fission reactor for power. Initially generating 300 kilowatts, the reactor would power a number of lasers in the engine that would be used to ignite inertial confinement fusion similar to that in Daedalus. The main design difference is that Daedalus would rely on the fusion reaction being able to power the ship as well, whereas in Longshot the internal reactor would provide this power.
The reactor would also be used to power a laser for communications back to Earth, with a maximum power of 250 kilowatts. For most of the journey this would be used at a much lower power for sending data about the interstellar medium, but during the flyby the main engine section would be discarded and the entire power capacity dedicated to communications at about 1 kilobit per second.
Longshot would have a mass of 396 metric tonnes at the start of the mission, including 264 tonnes of Helium-3/Deuterium pellet fuel/propellant. The active mission payload, which includes the fission reactor but not the discarded main propulsion section, would have a mass of around 30 tonnes.
A difference in the mission architecture between Longshot and the Daedalus study is that Longshot would go into orbit about the target star while Daedalus would do a one shot fly-by lasting a comparatively short time.
The journey to Alpha Centauri B orbit would take about 100 years, at an average velocity of approx. 13411 km/s, about 4.5% the speed of light, and another 4.39 years would be necessary for the data to reach Earth.

 

[Ventanni]

Let's consider this:

Our fastest spacecraft, according to my brief google search, is Voyager 1. It has been accelerating for quite awhile, and is currently travelling at 3.6 AU per year ( ~ 0.005% C, C being the speed of light). At that rate, it would take, well, nearly 70,000 years to reach the nearest star.
Let's say, for shits and giggles, we could produce a propulsion method that could take us to, eh... 3% the speed of light.
That would take over 130 years (both of these assume constant speed, not continued acceleration which would likely happen - but that's way too much data for me to dig up).
And, as of now, we are nowhere close to reaching a 3% capability. 1%? Without a miracle discovery of epic proportions (seriously, that would be a huge step for mankind), I don't see us even reaching that speed before the year 2100. IF we could reach 1%? Well, that would be roughly a 400 year journey to our nearest star! Given an ability to reach 1% C, there is probably acceleration, so depending how long it took to REACH 1%, that could be an 800 year journey.
A few generations, and a colossal ship.
Or a few drones, and we'd get the data back 4 years or so later. Imagine, we send a few drones out, 400 years later, we've discovered faster means of travel, we send new drones out, say 50 years later we get data back - and possibly a few hundred years later we'd get the data from the original drones!

Alright, fair enough, but you're considering terraforming Venus as being more practical? That's 900F temperatures at 92x the pressure of Earth's sea level (about the equivalent of 1 mile below the ocean). I guess what I'm saying is, if we're going to state that travelling the distances to nearby star systems as being impractical, we do realize that terraforming technology has yet to be invented, right? Any advancement in the field of terraforming could also be said for propulsion, and I'd be more willing to put my research dollars into propulsion since that'll get us places faster, even in our own backyard. Anyone up for mining the asteroid belt? At least that has economic sense to it.

To add to that, I'll assume we did have complete terraforming technology. How long do you think it would take such machines to terraform a planet? How much energy would that take? The main reason I ask is because it took several billion years before even Earth was hospitable to life. I imagine a 400 year journey in a colossal ship as being a blink of an eye in comparison, and who's to say we couldn't do that even faster.

I understand the thread probably thinks I'm crazy for considering travelling to an extrasolar planet as more realistic than terraforming a planet, but I'm just looking at the realistic energy requirements of filtering through 5-10 quadrillion tons of atmosphere (depending on the efficiency) in such harsh conditions, only to have it mean absolutely nothing given that Venus has no magnetosphere to protect itself, a day long enough to cook anything that did happen to be alive, no satellite to create tides, and the kicker of them all... there's no way to make water! The hydrogen is pretty much all gone. It's already been blown away by the Sun due to the lack of magnetosphere, and I brought that point up two posts ago. If Venus had the potential to harbor life, there's be life there, but instead it's the most inhospitable terrestrial planet in our solar system.

So that brings up the question, what do we terraform? Given that life exists here on Earth due to a very delicate and careful balance of scales, the only planets that would make sense to terraform are those that would fit the "Goldilocks" equation, but otherwise just haven't formed life yet. Afterall, it took several billion years for life to exists here on Earth. Such a terraforming machine would simply, well, speed up the process.

With that said, if we want to live in space, we have a lot of engineering and medical challenges to overcome. Power production is one, propulsion is another. Then there's the gravity part, as humans can't live long in both lesser and greater gravity environments. We then have to learn how to protect ourselves better from solar radiation. We have A LOT of challenges to overcome before terraforming planets or flying to nearby star systems even becomes practical.

I guess more probes to Uranus will have to do 'till then.

 

[William Gaatjes]

Venus is the closet planet to us, has both composition and gravity similar to Earth. We just need to come up with ways to deal with the sulfuric acid rain and incredibly high pressure and heat. But still, wouldn't that seem like a really cool venture to pursue?

Years ago I read based on some spectral analysis of the atmosphere they think there is some active organic chemistry going on there.

Such planets come in handy when you need a lot of energy. And have the means to process the energy and store it faster than the energy can consume you and destroy you.

Almost all Earth life would fall apart, even the lifeforms living near hydrothermal vents in the ocean. Because the water takes away a lot of the temperature and dilutes the sulfuric acids. If you want to live on Venus, you need to be able to guide the energy away before your own molecules fall apart. That means creating a small atmosphere that absorbs the excess of energy and leaves over enough energy to comfortably live in.
And on earth, only nature has partially been able to do that. Humans technology wise have not.

 

[William Gaatjes]

There can be life on Venus if an asteroid or meteorite containing sulfur metabolizing bacteria crashed on Venus. But these bacteria must also be able to withstand the heat and the pressure. I wonder if such a combination would make those bacteria vulnerable for oxygen. Oxygen being a deadly poison for such a life form.
Makes me think of a very young hot smoking earth...
And of molecules that allow electron flow very well. Very fast chemical reactions indeed. Way faster than what happens on earth. Must be so, to keep up with the energetic and possibly destructive environment.

 

[William Gaatjes]

Repairing damage as fast as it is happening... This can be seen with life forms such as bacteria and fungi living near energetic EM such as high power UV radiation or nuclear radiation. Fast dna repair is key to survival. And a lot of energy means fast reactions are possible because there is a lot of energy to absorb from the environment to drive the reactions. All that is needed are the right enzymes.

 

[Jeff7]

I do believe this is correct - but I didn't bother to research it further.
A 2005 article stated Voyager 1 was travelling at roughly 39000MPH. I did a conversion from NASA's page as of today, and it turned out to be roughly 37000MPH.
It would make sense, since it's in/near the heliosheath (outer edge) at the moment. I'm not sure if it's gravitational pull slowing it down, insomuch as increased pressure from the outer reaches and a slower solar wind.
Since it has breached escape velocity, at the edges of the "atmosphere" isn't the gravitational pull weaker than the craft has experienced up to that point?

Also, according to NASA's JPL page, it seems like they switched to the secondary thrusters to conserve the lifespan of the primaries - perhaps this is actually the biggest reason for the recent deceleration?

Voyager 1 "weekly" status - a little light on updates this year.
It's slowing down, slowly at that, only around 2mph/month.


I do know that there is some weird stuff going on out there as it's approaching the heliopause - they hit some point awhile back where the solar wind slowed way down, but "slow" for the solar wind might not mean too much, as it normally moves pretty damn fast.
But the gravitational force will drop off pretty consistently with distance, without much of any regard to the scarce particle density out there.
And I think that the particle density even at the bow shock itself would be considered a pretty decent vacuum on Earth.

In any case, the only things acting on those probes to speed them up would be the solar wind, force imparted by solar photons whacking into it, and its own thrusters. The solar wind and photons aren't going to impart a whole heck of a lot of momentum, and the thrusters are only there to keep the antenna pointed at Earth. They wouldn't have enough hydrazine in there to get very much of a speed boost anyway. They're not solar sailers, so they're going to be slowing down for quite awhile.
(There's also that Pioneer Anomaly thing that showed up, but that effect was extremely small anyway.)

 

[JTsyo]

I forget where I saw the concept (might have even been ATOT) but for Venus, it was a concept of a city on tracks that tried to keep on the terminator.

If the atmosphere can be adjusted on Venus, then the pole might become available for human occupation. It might not be a thriving colony but maybe just a outpost to mine the area.

One concept to cool Venus is to setup a solar shade, so that no direct rays from the sun reach the planet. Then either microbes or machines process the CO2 into something that's not a green house gas.

 

[BladeVenom]

I forget where I saw the concept (might have even been ATOT) but for Venus, it was a concept of a city on tracks that tried to keep on the terminator.

I don't recall that, but there was the concept of floating outposts on Venus.

 

[Jeff7]

I forget where I saw the concept (might have even been ATOT) but for Venus, it was a concept of a city on tracks that tried to keep on the terminator.

A derailed train would really suck.

Or...oh, right. That kind of track.
Durr.

If the atmosphere can be adjusted on Venus, then the pole might become available for human occupation. It might not be a thriving colony but maybe just a outpost to mine the area.

One concept to cool Venus is to setup a solar shade, so that no direct rays from the sun reach the planet. Then either microbes or machines process the CO2 into something that's not a green house gas.

Or some advanced robotics (With osmium, dammit!) to do any mining, if that's the goal, which could be done without the insanely long list of requirements for keeping humans alive anywhere for even a short period of time.

 

[SagaLore]

I forget where I saw the concept (might have even been ATOT) but for Venus, it was a concept of a city on tracks that tried to keep on the terminator.

This was in one of the Alistair Reynolds' books, but it wasn't on Venus, it was on Mercury.

 

[SagaLore]

I don't recall that, but there was the concept of floating outposts on Venus.

Yea this would be a lot of easier. The point where the cities would float is about 1 earth atmosphere of pressure.

 

[Ninjahedge]

4 pages and nobody expressed a desire to explore Uranus?


I am saddened.

 

[JTsyo]

4 pages and nobody expressed a desire to explore Uranus?


I am saddened.

go back and read post 40.

 

[marmasatt]

ATOT...I am disappoint.


OP, a much better question is...why aren't we ALL exploring Uranus?

HTH did it take 40 posts to even get to that. It's the first thing I thought of

 

[Ninjahedge]

go back and read post 40.

I did a word search.... I will have to scan back and make my probe for Uranus.

HTH did it take 40 posts to even get to that. It's the first thing I thought of

It's the first thing we all thought of.

It is a veritable black hole, it just sucks you in and doesn't give a sh.t about how you feel.....