cpast

And that actually requires using it from time to time. And hiring new people and running them through using it. And this requires paying trained staff, and having them show up for refreshers every so often. That's a good part of the cost of actually building the rockets; it is extremely expensive. Really, keeping a production line ready to reactivate requires reactivating it every so often; you can't keep it fully mothballed, or it will just not work.

By "pipeline," I don't quite mean that. What I mean is that production will proceed in parallel. SLS, for instance, doesn't seem like it'll be like that; it'll have few enough missions that at launch, the next rocket has either not started or is not far along. Most missions are like that; they spend lots of time and effort building a mission part, but only build the one. It's actually quite rare to want to build several of the exact same payload.

What are the other ways you're talking about? We're in agreement on Gemini. And, for that matter, on Saturn V. If you're building in parallel, you have much less time to wait. But that only works if you're already building a copy of the exact same vehicle when the first one fails, which means you have to plan on building several of these things. And that costs money; lots of it.

And by now, the equipment would have rusted, the building would be coming apart, and anything neither rusted nor falling apart would probably have been stolen and sold for scrap. When you try to reactivate it, you face the issue that manufacturing technology has come a long way, and so employees would have to go through significant amounts of training to learn how the old gear worked. There are maintenance costs associated with production gear. There are maintenance costs associated with factories. You can't operate it without trained workers, and all the trained workers from the Apollo days have retired (and even before then, they'd adjusted to more modern equipment, and not all would have been able to return). If you want to keep a production line running, you have to produce stuff every now and then. Reactivating a long-closed production line is extremely expensive, and may well be more expensive than just building a new one.

You missed the "if there's a pipeline" bit. The time it takes to build something from scratch is much, much higher than the time between rockets built in parallel (when one Gemini mission was rolled to the pad, the next was already mostly finished). If you aren't launching a bunch of identical things, that won't help you; you can't build from scratch in days, or weeks, and months is seriously pushing it. Which is why the rest of the mission has to be able to go without for a good while, unless you're building lots of identical things at once. For the replacement docking target: They did not build it in days. They had already built it before launching the first one, as a backup (which doesn't work if the modules are very expensive). And in their rush to launch the already-built rocket, they made mistakes that led to mission failure on the replacement (it could not be docked with, only rendezvoused with).

That takes over 100 m/s of delta-V to get to 600 km (the threshold after which it won't reliably decay after at most 25 years), which is very, very expensive on something as big as the ISS. It would be extremely expensive to boost it, for what is honestly not a whole lot of gain (if you charge enough to visit to pay for the boost cost plus interest, you will not get enough visitors to ever pay it off).

That doesn't work if the multiple parts are mission-critical; it only helps if you can last through the time it takes to prepare a replacement for launch (which, unless you have a pipeline, will be a fairly long time). If the multiple parts are mission-critical, and one fails, you lose everything. That's one of the major reasons EOR wasn't chosen for Apollo: by the time a failed manned launch was rerun, the previous unmanned launch would have fallen from orbit (and so failure of rocket 2 would lead to total writeoff of the mission; that, in turn, is why the people would be launched last). If you make sure the station can miss a launch without issues you're fine; however, your pieces must all be fairly capable, because the loss of one piece cannot result in mission failure. And it turns out that fairly capable pieces aren't small.

For one, the ISS orbit needs correction several times a year. You cannot just keep it in orbit indefinitely; regular resupply is needed (it has onboard boost capability, but limited fuel), and that's expensive. Tourist missions could provide boost, but you'd need to keep it in orbit until that becomes much more generally accessible (space tourism likely needs to fall in price by several orders of magnitude to fill this on any sort of ongoing basis; tourism is not a good source of income for extremely high-ticket things), which will take many, many years, if it ever happens (which I remain profoundly unconvinced it ever will). Someone has to pay to keep it in orbit until then; who will?

And how much would said hardware have been used over the years? Keeping production lines open is incredibly expensive, as is maintaining hardware that's sitting in a warehouse (you can't just stash some Saturn Vs around and expect them to work years later; unless you're actively maintaining them, they won't). NASA has a finite budget; it's not worth spending a large fraction of it on hardware that you aren't going to use, just so you can continue spending money on it to keep the parts you've built from rusting away, unless there's likely to be an urgent need to have hardware or production capacity on hand *right now*.

Also, having every engine aligned allows you to handle an engine failing. If the engines didn't track the CoM, an engine failing would result in massive torque. If you relied on differential thrust and *couldn't* gimbal an engine to track the CoM, you'd be unable to control this torque, leading to loss of vehicle and crew.

No; link?

To be fair: It's not necessarily having to have money "to spare." If you don't have people you want to leave money to, you'd be indifferent as to how much it costs and can spend up to your net worth.

Sorry, but I'm just not buying a 100 person flight to Mars for $50 million. Not without a detailed breakdown of exactly how you will launch 100 people and sufficient life support for months to another planet for less than it currently costs to put 13 tons in LEO.

How many colonists do you expect to have, exactly? You need 120 people paying that much to launch a single Falcon 9. So for the price of one current rocket that cannot take *anything* to Mars, you'd need to take 120 people. How many people would be able to spend that much *and* would be willing to go to Mars for the rest of their life *and* are suitable for the trip? (while you'd not need money afterwards, if you have a family that's not going you'd presumably want to leave something for them).

I've always been sort of confused by the hype over SpaceX. They're a commercial launch provider. They develop technology out of their profit margins, and the focus is on stuff driving down their costs. I just see no actual evidence that they're going to spend their own money on a mission without high commercial prospects; that's just not what they do (they don't even spend their own money testing new things on flights; they test stuff on the same flight as a paying customer's payload if at all possible). They only run missions with no customer if there's actually no alternative, and if there's substantial commercial advantage to be gained by doing so (e.g. new hardware, you can't find a customer till you tested it). I'm not seeing them running a colonization mission -- I'm seeing a commercial launch provider that uses vertical integration and cheap but good enough components to drive down costs, but which is focused on making money through commercial launches. Where is the money coming from for a Mars launch?

Land on Mars to what end? Unfortunately, "because it's cool" generally doesn't convince people with money to part with that money. SpaceX is no exception: they're a for-profit company that pays for its technology development by finding people willing to pay to launch payloads. So what justification will get someone who can afford to pay for a mission to actually pay for it?

Please, no. This amounts to "You MUST play the game this way or face massive arbitrary penalties; if you don't care for asteroid interception, too bad, that's a mandatory part of career." Also, it means failing one mission automatically makes you lose hours and hours of playtime on multiple missions unrelated to the failed one. If you decide you want your career to focus on landings and don't feel like asteroid redirection, adding this would mean you can no longer play career.

This is dead wrong. Every software product that reaches 1.0 does so without being as good as it could possibly be; that's because a developer can always think of something they wanted to add. The whole point of a release cycle is that to get the product out at some point, you have to eventually start locking stuff in and not changing it absent very good reason (no, "it could be better" isn't a good reason; a good reason is "it's unacceptable right now"). If Squad wants to ever get a 1.0 out the door, they have to at some point say "no, we have our 1.0 plan and we're not adding anything else until after release." An engine update has the potential to introduce many bugs that will take a long time to track down; that's the exact opposite of what you should do when approaching a release. This is a huge part of the role of producers -- to realize when something you want to do can't be done on a reasonable timeline to get in the game.

Not quite: the US and Russia have a treaty saying, among other things, that That generally supersedes normal sovereignty rules; Russia is in breach of the treaty if they refuse to let the US use ROS. The more detailed MoU between the agencies says that the agencies have to let their partners have access to their transportation systems (on a reimbursable basis). Russia can't legally kick the US out except by giving notice of withdrawal (which has to be at least one year's notice). They are expected to negotiate a withdrawal agreement, after which they can pull out their modules if they so choose. Russia doesn't own USOS, and can't control what the US does with it if they pull out; if they pull out they don't have to launch US astronauts, but the US can still launch US astronauts. If Russia withdraws, they also lose their rights to access USOS, because NASA owns USOS (they have treaty access, but if they leave the treaty they lose it). In practice...well, this is a treaty, and the question is "how much do treaties bind countries?" Russia and the US both have a very strong interest in not screwing around with the ISS (bad things happen when your mission controls are fighting each other), and denying the US access means they're in breach of a treaty obligation (which has about as much force as any other treaty obligation, plus means they lose any money from NASA that they get from the ISS program). Suffice it to say that Russia legally can't deny the US access to ROS or Soyuz without withdrawing from the ISS agreement (which requires one years' notice), and Russia and the US have a strong history of cooperation in space, and messing around with politics with a joint crewed space mission is a really bad idea, and the people who run the programs understand this.

No, the Moon's scientific name in English is "Moon." The Earth's is "Earth." The Sun's is "Sun." In other languages, the name is the common name in that language (so it is "Luna" in some languages, but not in English). There is no "registered" name; the IAU's official policy is "every language has a term for it, so use the term from the language you're writing in."

It is. And a ship in international waters is the sovereign territory of its flag state (international waters isn't a law-free zone; the law of a ship's flag state applies on board that ship).

Why? With any remotely realistic drag model, you'll end up *breaking* instead of *braking* if there's negligible atmosphere.

"Switching engines" is somewhat misleading terminology, because it makes it sound reasonably doable. "Porting" is better -- there is substantial rewrite involved in the change, and a huge amount of the knowledge you gain while writing the game is lost. It's just about never worth it.

Yes. That processor has an FCLGA1150, as does the i7-4770.

Shouldn't the air be rotating with Kerbin?