Asteroid as the basis of a Space Station

Wow, thanks Sig. We actually agree completely. And you know what we're going to need for these ships? That's right, Oxygen. (Now, if we could just make people that don't mess up their planet...)

Oxygen isn't that rare of an element. Spacecraft will need to have robust self-contained and regenerating environmental systems.

Venus isn't a very good candidate as a source of materials, or anything else for that matter. Beyond the fact of its harsh environmental conditions, even high altitude "floating" or skimming the atmosphere has almost the same energy costs as launching from Earth. It would be cheaper to go to the Jovian moons.

Barring the unlikely discover of life there, Venus is likely to remain useless and a scientific curiosity until we have the technology and resources to grossly change its character.

It's an inexhaustible resource. While I plan on recycling the oxygen, we're going to need a lot of it for expansion, which will require a constant supply indefinitely. Another resource is the sun which is relatively right there. We're also going to have to distribute whatever we mine, from whatever source to the rest of the system. Venus also has more energy than we need.

The Jovian Moons are Cold, (With the exception of Io, and you think Venus is hellish?) There's a nice big magnetic feild, but that's about it for energy, and the costs to send resources in system would be several times as much as from Venus. Jupiter is 4-6 AU away, as opposed to half to 1.5 AU to Venus (Depending on opposition.) To put that in perspective, at closest approach, Jupiter is more than double the distance of Venus on the other side of the sun.

Our sister planet also has the harmonic which allows regular shipments every five years, while the harmonic orbit (of Toutatis) doesn't go all the way out to it. Jupiter's gravity well would have to be fought a lot of the way back, and the orbits around it are crouded with rings, and gods only know how much Kessler debris before you have to pass through the main belt. It would actually take less energy to ship material from the Trojan Asteroids than the Jovian moons.

Doesn't matter if its too expensive (in propellant/DV) to get at it compared to other sources. Might as well lift it from Earth.



So what? You aren't going to go out for a smoke no matter where you are.




The cost is time, which with unmanned systems at least is much cheaper than propellant mass.

The slingshots back using the moons reduce the DV costs. Might even be faster than parabolic with ion drive-ish propulsion.

The reaction mass, and energy to accellerate it is there, so just get it from the atmosphere, and sun while you're there. There's no such option in the Jovian system.

Sarcasm noted. I'm not refering to comfort, but energy, or lack thereof. I just explained how Jupiter is more expensive on several fronts, by orders of magnitude, and you ignore all that to tell me Dominos doesn't deliver there?

Once you leave the Jovian system. With the exception of the sun itself, Jupiter is over half the mass of the rest of the solar system. It also doesn't put out the energy to counteract that gravity. Venus is too heavy, but Jupiter is not? What are you going to run this ion drivish propulsion with, static electricity?

Depends on your power and propulsion scheme is. If you are dependent on solar, then yeah you're sucking. But nuclear (or antimatter or dark energy, or zero-point, or whatever...), and that isn't a constraint.



I was attempting to point out that space is hostile no matter where you are.



You don't land "on" Jupiter, you land on its moons to pillage for resources. Landing, lifting off of them is low cost because of their low mass. Orbiting Jupiter give you considerable energy. Getting up to escape velocity doesn't take that much, especally if you play billiards with its moons. And then you can sling outward or drop to sunward easily.

I suggest you use the Orbiter sim to get a better feel for the dynamics of interplanetary travel.

Point being, to the intermediate future, there is not much point in messing with Venus because there is nothing to get there. The most you could do is penetrate its upper atmosphere to scoop up some of its nasty "air". The energy costs to do so and then re-obtain orbit isn't worth the benefit when you can get the same resources from the Moon, Mars, or just about anywhere else cheaper. Does not matter how close it is, it just isn't good real estate.

1) we have solar energy/ sails. 2) You'd have to ship this theoretical reactor out there, we don't have to move the sun to the center of the system. Moving inward enables In Situ resource utilization, which if you hadn't noticed, is what this thread is about. You're suggesting it's better to make it all from scratch based on weightless perpetual motion machines to power it to get resources which are harder to get in the first place. It isn't.

This is not news to me, I have said as much earlier in this very thread. You are also ignoring that I pointed out that you are ignoring that I pointed out that your scales, and energy budgets are completely reversed. Again.

I wasn't suggesting landing "On" venus, either. The surface, if there is one on Jupiter is under an ocean of LMH tens Earth diameters deep, so this is probably the opposite of practical. Jupiter's gravity doesn't end at the surface, it influences tides here on Earth, several AU away. I don't think you're understanding how trully MASSIVE that planet is. You're suggesting fighting that with gravity whips off the moons, not realizing that maneuver Saves energy, not creating it, and is only accomplished by transferring reaction mass which is a significan fraction of the entire vehicle with the energy to accellerate it.

I suggest you study a multiplication table to better understand the difference between tens, and millions. Your misgiving about venus as real estate are valid, but multiplied by orders of magnitude for Jupiter. In other words, Jupiter is just like Venus for these concerns, only more so. No matter how many theoretical buzzwords, like zero-point energy, and gravity whips you throw at it, the laws of physics don't change. My professors who graded me on papers involving orbital mechanics would argue with your assessment of my understanding of the concepts. While I'm not a professional rocket scientist working for NASA, I didn't fail, either. (I.E. I failed to get hired by NASA, but passed the courses.)

How about using the regolith as a base for a type of "shotcrete"http://en.wikipedia.org/wiki/Shotcrete

Also see Lunarcrete: http://en.wikipedia.org/wiki/Lunarcrete

I'm familiar with those concepts, but it would be a lot less expensive in therms of money, mass, and energy the less we have to take with us. Ice would be an ok way to fuse the walls, if you don't mind living in an ice box. I was thinking more along the lines of heat fusing, into something like dirty glass. That requires only energy, which weighs nothing.

What about using a drill, and then a rotating high energy laser, moving at a rate that would make "Dirty glass", you could stop once in a while and burn a very small shaft, and make "anchors", with 3d printing tech you could harden sections, make shapes, cut them out like a cookie cutter, grab it, and essemble 3d structures

A drill would be needed for a solid rock, but rotating heads aren't a great idea in space, or entering a surface, because you would tend to rotate in place like a turntable rather than penetrate the surface unless you added outriggers, which would get in the way of entering through your nice round hole. Once you were in, you could brace against the sides, no problem, but you'd have to get in first.

Right now, we're talking about a rubble pile type scenario, because that's the greatest engineering challenge. What I'm envisioning now is a cylindrig Plasma Gassifier, to boil off volatiles (Non, and light metals) and pumping the molten flux out to reinforce the sides. Other processing steps could be added to sort out the desirable from undesirable, probably through counter-rotating centrefuges so you wouldn't have to depend on the object's gravity to sort by mass, and so it could be done in stages. Fairly complex (It's an automated factory) but lightweight until it actually gets there, and takes on mass to process. May be filled with fuel with an engine on one end, so it's self propelled, and possible Cannon fired from a lunar base.

Kind of not unlike a Ramjet for tunneling through reasonably fine regolith (Not too chunky.)

What about using a 3d printer, that prints with dust and laser and a large nuclear generator? you could assemble a docking system, anchor it with long shafts into the surface at angles, and start "Drilling" but it would actually be more like excavating to acquire more building materials and getting a nice tunnel at the same time,

Ok, now that actually sounds like an idea, make it a cylindrical work envelope (With a SCARA type articulation on a telescoping prime axis) to make round tunnels. What were you thinking on using to fuse the walls, heat? Make that a small isotope reactor (The ones on the Voyagers are still running!) if it's automated, there's no hurry, but Mass is, as always, at a premium.

[edit]Ok, let me say this formally: Thank you Sigma, for stimulating me with the idea to make my concept of an Asteroid mining robotic probe more practical. I was wracking my brain to figure out how to make a tunneling miner, when that would probably be too massive to get there on any kind of budget. The new plan, partially thanks to you, is a tripod suspending a SCARA (Selective Compliance Articulated Robotic Arm, look it up, it's one of my favorite designs) on a telescoping first axis to lower into the artificial crater, and fuse the walls into a cylinder. (Most likely a much less massive design.) It might take years, but with the orbit of a periodic asteroid like 4179 Toutatis, you'd have them. Don't let this go to your head. You're still designing on the Machinegun Effect (If you throw enough ideas out there, eventually one will hit) but you lucked into a good'un this time!..[/e]

One is glad to be of service

I like you and JamesG science, does not exist without peers.

Quoted for truth.