Nibb31

A Mars colony will always be dependent on re-supply shipments from Earth, just like America is dependent on imports for lots of stuff (including food, energy, and hi tech devices). A Mars colony, to have a viable economy, is going to need a commercial balance just like any other country. That balance will pretty much always be negative, because there are no resources to export. Yet you want it to still attract investment from Earth and immigration. Increasing population should not be a goal. Population should be controlled so that it matches available resources. That's basic ecology that will need to be applied everywhere, regardless of the environment, if we want to be a sustainable species. But you don't need to go to Mars to do that. We could build Earth colonies that could reach over the oceans for a fraction of the cost of living on Mars.

Crop failures happen on Earth and people die. It's not a matter of working hard or not. I'm not. You are demanding a huge investment from society/investors/corporations/governments to establish a city on Mars that might or might not work, then to send millions of people for a leap of faith (figure it out or die), and then 100 years later, the investors might recoup their investment in... IP ? It doesn't make any sort of economical sense. And you think there will be individual farmers ? If the colony is set up for efficiency at a huge expense by private corporations, then it will most certainly be industrial farming with heavily automated crop production facilities. There will be handful of jobs as agricultural technicians employed by the corporation, but that's it.

The key is getting from zero to a "mature colony" without thousands of settlers dying in the process.

If that's the sort of life that you are offering to millions of settlers with their families, it doesn't sound too compelling. Working hard isn't necessarily the key to survival. You can work as hard as possible, but that won't save you from dying if your crops get sick or you get a CO leak in the colony's air recycler. Your pulling numbers out of thin air is getting ridiculous. You're are at least 2 orders of magnitude below what it would need to build an industrialized country from scratch. Also, it took Germany hundreds of years to become the country it is now. And it isn't self-sufficient. You really can't speak in terms of investment when the return on investment is hundreds of years into the future. Nobody in a capitalist society operates at a loss over several generations in the expectation that their great grandchildren might profit one day. It would be great if it worked like that, but it simply doesn't. If you have $200 billion to spare to make the world a better place, there are much more effective investments than a Mars colony.

There has to be at least ballast, otherwise your trajectory will be screwed up. Musk has said several times that he wasn't too confident and that FH has proven much more complicated than they expected. I took that as admission that it was pretty much a dead end.

Boosters are at the cape. The launch is scheduled for december. Payload unknown.

Mars resources have a cost. Food, water, housing, on mars will cost much more to produce than the equivalents on Earth. Workers on Earth are motivated by the prospect of spending that money on luxuries, leisure, tourism, entertainment. Those will cost more on Mars or will be inexistent. So that doesn't explain why Mars would produce more IP than Earth. That is a lot of assuming. We aren't capable of making a self sustaining city on Earth. What makes you think that it will be feasible on Mars ? Our entire technological civilization is based on exchange and specialization. Self sufficiency was thrown out the window as soon as our hunter-gatherer ancestors settled down and started bartering with each other. Having both high-technology and total self sufficiency at the same time is not practical, nor even feasible. In the long run, once you have a million people living in a self sustaining Mars city, then everything works out. Sure. The only issue is that there is no practical way of going from zero to a million people living in a self sustaining Mars city. Also, dumping people on Mars actually has more chance of making them dead than technically skilled. Were are you getting those numbers from ? So where does the money to sustain the Martian economy come from ? Economies are not isolated systems. How exactly do you have an economy if everything is self sustaining ? What goes in, what goes out ? Who is going to pay for a massive investment that will only start returning value after 100 years ? Especially for if that value is immaterial intellectual property. The brain work is going to have to happen on Earth before you send people, otherwise you just end up with a lot of dead settlers. And how does that happen ? They have to just "figure it out" or they die ? Guess which is more likely.

If people can use trucks and airliners as weapons, I don't see why this doesn't have the potential of be used as a weapon too. But the question was rather how does a country's defense system distinguish an incoming passenger flight from an incoming ICBM. A lot of people won't be too keen on seeing suborbital hypersonic projectiles coming down on major cities. The question is moot though, because there are so many impracticalities that it will not happen in any foreseeable future, and certainly not in the form that was presented in the CGI videos. Musk presented this for its clickbait value, and a lot of people are focusing on it as if it was the big news of the presentation. It wasn't. It's just an afterthought.

It hasn't really be done before because it hasn't really been needed. I don't see it as a huge problem as long as the system is designed for the appropriate structural loads. F9 already uses mechanical latches for attaching the first and second stage. It has to be super reliable though, especially with the BFR architecture, because if a latch fails to disengage, you risk losing both vehicles.

It's still a single node. Just bigger. Fuel that comes out of the source tank needs to be replaced with filler gas. Filler gas is vented from the destination tank. It's simpler to just recirculate the filler gas from destination tank to the source tank and let acceleration (or gravity ;)) do the rest.

Yes, corrected.

Aligning 4 points or 1 is exactly the same mathematical problem. You need to align X, Y, Z and rotation in exactly the same way. The CGI renderings are not showing docking radar antennas or sensors for automatic alignment. I would probably add a structural ring around the engine area with a set of latches. You don't want to put the stress of two huge spaceships on those fuel lines. You need fluid and venting: fluid goes one way, helium or filler gas goes the other. The CGI models gloss over a lot of details (the landing legs and solar panels are missing in most of the shots, as well as RCS pods, antennas, etc...). They are definitely not accurate renderings of a mature design that is supposed to start construction in 6 months.

4 pipes = 2 LoX for liquid methane, fluid and venting for each. No redundancy.

Not gravity, thrust. You need to be thrusting for the whole duration of the refueling.

Yeah, I wonder how you land on an off shore barge in London, Paris or Berlin.

That makes zero sense.

The design evolved from 12m diameter, which was impractical for many reasons, to 9m, but it's the same project. You have to expect more changes. It's a work in progress.

What's does Mars IP have that Earth IP hasn't ? How are 5000 engineers on Mars pour productive than 5000 engineers in Bangalore or Guangzhou ? The whole point of IP is that it's immaterial, so it can be outsourced to the cheapest locations, not the most expensive. And you don't need to throttle to hoverslam.

The P2P plan is not practical in any sense. Not gonna happen. Not worth discussing at this stage. Can we please get over it ?

Apollo was economically feasible because it was actually done.

Not the name of a bird of prey (Kestrel, Merlin, Falcon, etc...) or a dragon (Dragon, Draco...). Try again.

Depends on your tongue. Don't be so anthropocentric!

BFR is the internal codename. ITS was mentioned last year, but Musk said that he didn't like it. The community changed it to ITSy when it downscaled to 9m, but clearly the 12m version wasn't realistic. He said they still haven't come up with a good name. How hard can it be ? It's not like there is a lack of names on the theme of birds of prey or dragons, which is what they have been using until now. Just call it Lammergeier and be done with it.

What do you mean ?

Because it's done and they have a couple of paying customers. They might as well fly it at this point.