what places in the solar system should we visit after mars and moon

[DunaManiac]

For manned missions, I would focus on a floating settlement on Venus (https://www.citylab.com/life/2014/07/the-surprisingly-strong-case-for-colonizing-venus/373560/)

Then I would focus on asteroids, then possibly Titan (you don't need a full spacesuit due to the atmosphere).

[Hannu2]

On 12/30/2019 at 8:31 PM, kerbiloid said:

Wiki says, Antarctica contains 30 mln km³ of ice.

That's a ~400 km ball.

So, we can easily make our own Minmus to fly there for skiing, skidding, and skating.

 

(Penguins can be relocated to the North, as anyway nobody can see them where they are now.)

I would use some other word than easily. At least it you include begging of funding.

How much polar bear union paid for you? That penguin "rescue" operation would mean few easy years for bears.

My choise would depend on tech level and funding. There are no techical or scientific reasons to send humans anywhere. I would probably prefer better research stations on Mars and Moon, but if politicians wanted and payed propaganda tricks, a visit on Kallisto would be nice and prestige. Especially if they gave a license to develop and use nuclear propulsion technology too. Asteroids would be so boring places and it is not very realistic to assume radiation shielding for manned operations on inner Jovian moons.

Edited January 1, 2020 by Hannu2
Better sentences

[magnemoe]

On 1/1/2020 at 8:59 PM, Hannu2 said:

I would use some other word than easily. At least it you include begging of funding.

How much polar bear union paid for you? That penguin "rescue" operation would mean few easy years for bears.

My choise would depend on tech level and funding. There are no techical or scientific reasons to send humans anywhere. I would probably prefer better research stations on Mars and Moon, but if politicians wanted and payed propaganda tricks, a visit on Kallisto would be nice and prestige. Especially if they gave a license to develop and use nuclear propulsion technology too. Asteroids would be so boring places and it is not very realistic to assume radiation shielding for manned operations on inner Jovian moons.

LOL, yes penguin are not designed to handle land predators. Dogs are outlawed in Antarctica for this reason, main reason is that the Greenland dogs commonly use for sleds dogs probably could survive there and if you had an breeding pair on the run they would do untold damage to brooding penguins and would be an nightmare to wipe out that dog population once it started growing. 

[kerbiloid]

Spoiler

  

8 hours ago, magnemoe said:

Dogs are outlawed in Antarctica for this reason

While cats arre just enough clever to avoid this cold trash themselves.

 

[Codraroll]

I'd say, go for Mercury. It's a big ball of metal with as much solar energy as we would ever want, and statistically it's the closest planet to all the others because of the way orbits work. Practically infinite metals, practically infinite energy, and a relatively short hop to everywhere else. If we become advanced enough to colonize Mars, Mercury would be a good place to set up the next shop.

[kerbiloid]

2 hours ago, Codraroll said:

It's a big ball of metal

Below tens of kilometers of rock.

2 hours ago, Codraroll said:

statistically it's the closest planet

While energetically, it's one of the fartherst.

[Bill Phil]

On 1/1/2020 at 1:41 PM, DunaManiac said:

Then I would focus on asteroids, then possibly Titan (you don't need a full spacesuit due to the atmosphere).

You don't need a pressure suit, true.

But making a suit that's heated enough to let a human survive that environment...

It's 94 kelvin on the surface...

Only about 30 kelvin above the temperature range for high temperature superconductors.

[Retro Starship]

On 12/30/2019 at 12:33 PM, razark said:

All of them, except Europa.

We should attempt no landing there.

Open the pod bay doors please Hal!

 

I agree, we need to go to Europa as well as Titan... Even though its a bit tuff rocket power and time wise, we just need to do it!

Edited January 7, 2020 by Saturn5tony

[kerbiloid]

About the penguins.

We can leave them on their ice land. Just by moving them all to the artificial Minmus.
If it has enough air for tourists, it's also enough for the penguins.

To let them swim we can make an ocean under the ice, like on Europa but with access holes.

Also in the low Minmusian gravity they can even fly by waving with their winglets.

[Hannu2]

On 1/7/2020 at 2:47 PM, kerbiloid said:

Below tens of kilometers of rock.

While energetically, it's one of the fartherst.

It is the most expensive (in dv) place to go with huge difference to any other celestial body in our Solar system. It is also far cheaper to launch spacecraft out of Solar system than brake it on orbit around Mercury. Mercury probes have been small and used very complex trajectories with lot of gravity slingshot flybys of Venus and Mercury.

Those metals are much easier to get from metal asteroids. They have much higher concentrations, much lower gravities and not extreme level of solar radiation, which does not make energy production cheap and easy.

[Ultimate Steve]

Assuming Starship works IDK if it will be better to build a bigger Starship or build a mothership using the existing Starship, or use the bigger Starship to build a bigger mothership, but once we have Mars figured out maybe using Starship to assemble a giant nuclear powered mothership with Starships attached as landers and then sending the whole thing to Jupiter and maybe later Saturn may be a good idea.

This would be risky but if the ship expended all of its fuel just getting to the orbit of one of the moons, the Starships could mine fuel and refuel the mothership over the course of many landings, leading to a far shorter transit time than taking all of the fuel to begin with. However, this is fairly still limited.

The real fun starts after we build a working nuclear fusion thermal rocket engine. Specific impulses measured in tens of thousands unlock a lot of options.

Just workable power producing fusion reactors are still a ways off, but those will probably happen in my lifetime. From there it is a lot more work to get it workable in a rocket engine, but one can hope.

Edited January 17, 2020 by Ultimate Steve

[Bill Phil]

9 hours ago, Ultimate Steve said:

The real fun starts after we build a working nuclear fusion thermal rocket engine. Specific impulses measured in tens of thousands unlock a lot of options.

Just workable power producing fusion reactors are still a ways off, but those will probably happen in my lifetime. From there it is a lot more work to get it workable in a rocket engine, but one can hope.

Don't need fusion for that.

Z-Pinch fission can get up to 20 thousand seconds, and fusion boosted fission (using fusion reactions to increase the neutron flux to increase fission burnup rate) could get above 100 thousand seconds. 

Could even make it like VASIMR/LANTR - adding in an "afterburner" to get more thrust when it's useful. Of course most of that usefulness is either escaping a gravity well or launching from a planet - which is probably never going to happen with nuclear propulsion.

[Starman4308]

So, opinions:

Mercury: Hard to reach, even with complicated time-consuming MESSENGER-style flyby series. Elevated solar radiation. Extremely long day/night cycles, virtually mandating a nuclear-based night-time power system anywhere except elevated polar regions where are in constant sunlight. Baking on the day side. Freezing on the night side. Very little in-situ water. The metals it has are more easily obtained from asteroids. There's almost no reason to visit here with a manned mission until solar system travel becomes borderline routine.

Venus: The surface is basically a no-go for manned missions, being a high-pressure anoxic incinerator. Even robots will struggle there. I would describe the surface as "WHYYYYYY". The upper atmosphere and cloud cities can be described as "why?" You can conduct some experiments, but those can be handled by robots at much less cost and risk, and I'm not really aware of any atmospheric resources worth bothering with there.

Earth: I hear the outdoors is scary. I'm playing it safe and not conducting any crazy missions to the outdoors.

Moon: Close enough for reasonable tourism, may be a source of He3, and close to us in many, many senses. Any interplanetary shenanigans should really start here. Some issues in a long day/night cycle (you need to pack either a nuclear power source or 14+ days of batteries/regenerative fuel cells), but has that overwhelming close-to-us thing going for it.

Mars: At least a thin atmosphere with fast winds (permitting wind turbines). Day/night cycle beautifully close to Earth's, good from both a power perspective and a human-diurnal-cycle perspective. Distance is pretty borderline for "need mature solar-system travel". Surface resources likely more easily accessed than Earth's from an industrial perspective, but it'd be an awful bear shipping it back. I rank this third on the priority list.

Near-Earth asteroids: Plenty of rare-Earth metals. Relatively cheap and fast to get to. Number 2 on my to-go-to list courtesy of relative ease of travel, plentiful solar power... and those rare-earth metals.

Nearby dwarf planets (e.g. 4 Vesta, Ceres): Of some scientific interest, but increased dV requirements and likely lesser concentrations of rare metals disfavor these bodies.

Jovian moons: Its most interesting moons are all within murderous radiation fields, and its outer moons are tiny iceballs. No real reason to go here before near-Earth asteroids.

Saturn's moons: Some interesting moons, but Saturn and beyond is going to require very mature solar-system travel due to the very long distances.

Beyond Saturn: See above.

 

Overall, I don't really see reasons to visit anything other than the Moon, near-Earth asteroids, and possibly Mars until the relevant technology is basically sci-fi level. I dislike speculating beyond there, because by that point, we don't know what the limiting factors and tradeoffs will be.

[wumpus]

27 minutes ago, Starman4308 said:

Near-Earth asteroids: Plenty of rare-Earth metals. Relatively cheap and fast to get to. Number 2 on my to-go-to list courtesy of relative ease of travel, plentiful solar power... and those rare-earth metals.

Overall, I don't really see reasons to visit anything other than the Moon, near-Earth asteroids, and possibly Mars until the relevant technology is basically sci-fi level. I dislike speculating beyond there, because by that point, we don't know what the limiting factors and tradeoffs will be.

I'd expect that asteroid mining will eventually be a thing, but done with robots until proven valuable enough to bring humans along and that humans can get enough done that robots can't.

[kerbiloid]

13 hours ago, Starman4308 said:

Mars: At least a thin atmosphere with fast winds (permitting wind turbines).

With almost zero "air" density. The turbines would stay still and get dusted.

13 hours ago, Starman4308 said:

Near-Earth asteroids: Plenty of rare-Earth metals.

presumed. But, captain, the team asks: do we have the map of treasures?

13 hours ago, Starman4308 said:

Jovian moons: Its most interesting moons are all within murderous radiation fields, and its outer moons are tiny iceballs. No real reason to go here before near-Earth asteroids.

Callisto.

[Bill Phil]

14 hours ago, Starman4308 said:

Moon: Close enough for reasonable tourism, may be a source of He3

No, the Moon is a bad source for Helium-3. Uranium and Thorium are more abundant by orders of magnitude and in similar abundances as Earth's surface.

The concentration of Helium-3 on the Moon is so miniscule that it may not even be an energy positive process, and no matter what the energy return on investment will be tiny.

No, there's really nothing in space worth bringing back.

That said a mature industry in space would be awesome and could enable some very interesting missions.

14 hours ago, Starman4308 said:

Overall, I don't really see reasons to visit anything other than the Moon, near-Earth asteroids, and possibly Mars until the relevant technology is basically sci-fi level. I dislike speculating beyond there, because by that point, we don't know what the limiting factors and tradeoffs will be.

Well Mini-Mag Orion could open up Jupiter exploration, and if not it would certainly open up Asteroid Belt exploration. 

Not sci-fi at all. Though a mature industry in space would certainly help.

[Starman4308]

17 hours ago, kerbiloid said:

With almost zero "air" density. The turbines would stay still and get dusted.

presumed. But, captain, the team asks: do we have the map of treasures?

Callisto.

On air density: yes, it's sufficient. See the relevant Scott Manley video.

https://www.youtube.com/watch?v=0xtW7g4R_vs

On your non-sequitur: it's a non-sequitur intended to evade the point.

Callisto: point taken, even if there are still issues involving the long distance and high dV requirement.

[kerbiloid]

7 hours ago, Starman4308 said:

On your non-sequitur: it's a non-sequitur intended to evade the point.

Sounds too wise for me, didn't understand.

But still waiting with interest for any list of osmium or hafnium extractable deposits on asteroids, rather than just presumptions of their existence.
Say, the Moon contains a lot of He-3. But in ~1 g of He-3 per 100 t of regolith concentration in best places. This makes it practically useless.
I don't know at least one reason why asteroid metals would be not scattered same way. They even didn't have geothermal water plumes to wash something up as surface spots or an ocean to let something sink and concentrate as a spot on the bottom.
So, it would be nice to know a potential platinum mine location.

The asteroid belt is a slag dump behind the abandoned metallurgical plant. Stones, rust, pieces of iron, coke dust, pieces of coke. Sometimes big.

Spoiler

So where to dig exactly?

7 hours ago, Starman4308 said:

On air density: yes, it's sufficient. See the relevant Scott Manley video.

https://www.youtube.com/watch?v=0xtW7g4R_vs

Took a look at this relevant video. Now try this yourself, too, again.

Except the resounding blah-blah, handwaving, and a videogame, the only relevant part of the video is the 02:10 picture with given data.
Where is a calculation result?

"NASA makes a project of Martian turbines". Antarctica has normal 1 atm air pressure rather than Mars, btw. Nobody doubts that wind turbines work in the Earth air.

"Average wind speed is 10 m/s like in Chicago". Like Antarctica, Chicago has normal 1 atm air pressure. If the air density in Chicago was 100 times lower, it would be an argument. At the moment - it isn't.

"Dust devils", "dust storm", "dust dunes". Look at the comet, we can see it from several AU distance, why not try a comet wind turbine, too?

Edited January 20, 2020 by kerbiloid

[Starman4308]

13 hours ago, kerbiloid said:

Took a look at this relevant video. Now try this yourself, too, again.

Except the resounding blah-blah, handwaving, and a videogame, the only relevant part of the video is the 02:10 picture with given data.
Where is a calculation result?

"NASA makes a project of Martian turbines". Antarctica has normal 1 atm air pressure rather than Mars, btw. Nobody doubts that wind turbines work in the Earth air.

"Average wind speed is 10 m/s like in Chicago". Like Antarctica, Chicago has normal 1 atm air pressure. If the air density in Chicago was 100 times lower, it would be an argument. At the moment - it isn't.

"Dust devils", "dust storm", "dust dunes". Look at the comet, we can see it from several AU distance, why not try a comet wind turbine, too?

That's 10.3 mph in Chicago, or about 4.7 m/s. And, as was pointed out, energy generation is roughly proportional to the cube of wind speed; a factor of 2 increase in wind speed gives you a factor of 8x more power generation.

[kerbiloid]

3 minutes ago, Starman4308 said:

That's 10.3 mph in Chicago, or about 4.7 m/s.

P ~ density * speed³.

When the density is 100 times lower, the power is 100 times lower as well.

[dave1904]

Moons of neptune and uranus. Mars is boring anyway. Would personally prefer 2 outer solar Orbiters instead of any furture mars missions. I want missions that give us more questions than awnsers. Every single moon in the outer solar system has such a unique story. Miranda and Triton are also 2 of my favourite objects. 

Edited February 5, 2020 by dave1904

[farmerben]

 

Humans landing on every moon and major asteroid is just plain cool.

But what I really want to see is missions that can make orbital mirrors.  Once you can do that you are on the way to terraforming venus and building interstellar laser propulsion.  They don't even have to be good mirrors, any combination of metals no matter how weak is useful, so it's just a matter of production economy.  How do you separate the gas, freeze it, and roll everything else into sheets.  

[The Blazer]

Honestly, I've always thought that if Mars is colonized, and we can produce fuel on it, the Asteroid Belt will be our next destination, so I vote for Ceres and Vesta. It's far cheaper to get there from Mars, than from Earth.

[dave1904]

53 minutes ago, The Blazer said:

Honestly, I've always thought that if Mars is colonized, and we can produce fuel on it, the Asteroid Belt will be our next destination, so I vote for Ceres and Vesta. It's far cheaper to get there from Mars, than from Earth.

It would never be cheaper because the demand is not there and will never be. You would need to have the infrastructure to produce fuel and rockets on Mars. Even if they are earth built rockets you will need someone to service them. If you had a colony you would most likely have the propulsion to go from Mars to earth on the same vessel on a regular basis. Producing fuel on Mars is a very unrealistic idea because a self sustained colony is just no benefit to anyone here on earth. We are selfish. Earth has everything mankind needs so it's better to take care of her. If your goal is to mine asteroids you need to bring the resources back to earth and leave anyway. Imo also pointless.

[Dirkidirk]

On 1/19/2020 at 1:03 AM, Bill Phil said:

No, the Moon is a bad source for Helium-3. Uranium and Thorium are more abundant by orders of magnitude and in similar abundances as Earth's surface.

The concentration of Helium-3 on the Moon is so miniscule that it may not even be an energy positive process, and no matter what the energy return on investment will be tiny.

No, there's really nothing in space worth bringing back.

that seems to be the case.

 

after the moon, mars and It's moons, I would send a mission or two to nearby asteroid(s), and after establishing a mars colony send a manned mission to the atmosphere of venus for no reason other than just because. after that a mission to the nearby dwarf planets, then a couple decades later a mission to jupiter.

Edited February 6, 2020 by Dirkidirk
memes