Seret

Unmanned probes don't have to come back to complete their mission, which simplifies things hugely. Eve is the ultimate example; it's a doddle to get science from it with an unmanned mission but a mare with a manned one. Tbh a good percentage of my game is unmanned. I only send along a Kerbal in a can if I'm trying to get some science that necessitates it. Kerbals are just dead weight most of the time.

Why? You don't get anything extra for it. This is only a problem for RPers and folks using life support mods. I even have a rule for Jeb, he never goes back to Kerbin. He's a spaceman, once he's up there that's where he lives. I only bring the others back is if I need someone to ride a pod full of science down, and that would be whoever rode it up. Bringing a lab crew back would just be a pain, so why bother?

Indeed, scientists have long wondered about alternate chemistry such as silicon for life. They're also very interested in extremophiles that might expand our concept of what life can handle. When it comes to actually looking it makes sense to first look for the stuff when know exists for certain. We can look fit the speculative stuff later if we strike out looking for Earth-like life.

Of course. Move a conductor through a magnetic field you'll always get some. Likewise move a field through your conductor (eg: an alternating field that expands and collapses continuously) and you'll get power.

Definitely, but the question was whether it's appropriate to spend time identifying risks for a prospective future mission. My point was that there was good stuff to be discovered by doing it early.

See now the constructive thing to do instead of complaining would have been to add the missing info to the wiki page...

There's one on the KSP cheat sheet page, which is so full of awesome it should probably be in your bookmarks.

While the game is in development the most sensible place to document it is the wiki. Plenty of good info on there. I would advise people to think twice about producing parallel guides, it'll just dilute community effort. If you're producing good stuff, put it on the wiki.

I disagree, there's some very good decisions you can make once you've identified the fact that your data is woefully inadequate. Such as: let's not proceed.

Yes, there is a certain amount of (hopefully educated!) guesswork that has to go on. That's why it's also important at that stage to also identify your assumptions. These are then re-checked as you progress. Realising that you don't have good enough data to quantify the risks is a good thing. It's the whole reason you do things like feasibility studies and talk about risk as early as possible. If you didn't do it, you'd never know you needed to do the work required to quantify the risks, and that would be baaaaaad. Look, I don't know what you do but engineering projects are bread and butter for me. This is my day job, I know the process.

Nope, you've got that one backwards. You need to do the planning and identify the risks first so that you know what technology to develop. If you look you'll find space agencies have indeed done loads of studies into what a Mars mission might look like. Obviously as you progress you go back and re-plan, so it's a continuous process too. But you need to do the thinking before you start the doing, or you might just head off in completely the wrong direction.

I've not eaten American MREs, but the ration packs we used to eat in the field were perfectly ok to be eaten for as long as you like. In reality most people would supplement them with extras of their own but that was just due to personal preference and creature comforts. There were a lot of calories in a 24 hour ratpack, I can't remember how many exactly but it was enough to keep big guys going all day marching long distances with kit and digging holes.

Yes, and no, depends what you're talking about. They're less likely to experience failures, because they're smaller and simpler. But they're also allowed to fail, so you can make less conservative decisions about technology and reduce the levels of redundancy you're packing. Manned missions are overall less likely to fail because they're much more paranoid about failures. They have to be. But the costs of that are extremely high. Of course, sometimes risks only become apparent during development. However, you always want to try your damndest to identify them as early as possible. New risks that are identified during development will inevitably throw a major spanner into your programme. Ideally you want to think about your risks as early as possible. Your example of cancer risks actually proves my point. You've already identified that risk. You've also identified that that risk presents another risk, in that we are short on data that would enable us to quantify the significance of the first risk. This is a really good example of why identifying risks well in advance is useful, as in this case it has identified the fact we need to do some work before we can think about mitigating the first risk. That's exactly what I meant when I said that identifying risks early defines the way forward. This is not rocket science though. Read any book or watch any lecture on project management. Risk analysis is started during the planning phase of any project, whether it's a mission to Mars, or replacing the cash registers in a chain of stores.

On a very simplistic level it's just the relationship between pressure and force. If you have a difference in pressure then you must have a force being applied. If there's no force opposing that (such as a reaction force from a vessel wall) then the system is unstable until the pressure difference goes away.

It would work fine if you had opposing sets of RCS thrusters. You'd just be converting monopropellant to electricity at pretty low efficiency. Given the severe weight penalties that spacecraft operate under I don't think using mass to generate power is a great idea.

That's the perfect time to identify risks, since they define how to proceed (or if it indeed it is possible to proceed). Taking about risk is a routine engineering activity.

I meant risk in a general sense. Death of an astronaut is only one of many risks. Others include loss of science output, financial losses, impact on other projects, etc. In general risks are assessed in terms of their likelihood and their impact. Unmanned missions are both less likely to fail and have a lower impact when they do. This makes them far cheaper and quicker, as failure can actually be tolerated. And that's why we don't send humans on exploration missions.

The lab is less useful for Duna, but excels at the Mun, Minmus and Jool, where there are many biomes within striking distance. As we get more biomes and we have to pay for each launch then recycling science landers will get even more useful.

Sure, if you're ok with Common Sense providing most of the protection. MSE seemed pretty good when it first came out, but has been getting terrible results in tests lately.

Of course, because right now we're doing almost nothing. That's because there aren't a lot of really compelling reasons to go there beyond flag planting. Robotic exploration has proved to be highly effective, relatively cheap, low risk and very much within our capabilities. There are techniques that can be used to estimate that kind of thing that have proven surprisingly accurate. An example is Delphi, which I believe was used for the Apollo Program.

Well exactly, hence my question. FWIW orbit is essentially a spherical space, with a vertical component which is why I asked if it was reckoned in relation to whatever body you were orbiting. I understand that in practical terms they use things like inertial updated by GPS or star shots, but I was wondering if there was an underlying conceptual framework or if it's simply redundant.

x1000 AIUI their projections are based on viewer numbers equivalent to an Olympic event. The trouble is that the Olympics is two weeks, there's no way you'd sustain that level of interest permanently, when all the folks would be doing is sitting around cooped up in a Dragon and occasionally going for a walk in a big red carpark. The sceptical part of me thinks they're not really intending seriously to send anyone to Mars. They just want to drum up buzz and sell a reality TV programme about the trainee astronauts. Hopefully not anything like Space Cadets...

Sure but there's a limit to what you can achieve by throwing money and resources at a project. You get diminishing returns for every extra person you add, and past a certain point it has no benefit. Granted something like a Mars mission is so big that you're able to atomise it down into lots of little projects, but there's a limit to how much you can do that too, or the interfaces will come back to bite you. Apollo accepted a fairly large amount of risk as the trade off for speed, they were lucky things went as well as they did. Ditto the Manhattan Project, but in that case it was wartime so elevated tolerance of risk was more the norm.

By definition cardinal points can't be based on your own orbit, they should be the same for everybody regardless of how they're moving. I'm genuinely interested, since I know next to nothing about navigation in space. Is the concept of a cardinal point even relevant? Does it change when you move from one body to another, if so, is there an equivalent used for interplanetary navigation?

I don't think the OP phrased it particularly well, but it seems their intent was to examine what our options were if the climate entered a point where further warming was driven partly or predominantly by positive feedback rather than by human emissions. In other words they wanted to look at options other than reducing emissions for reducing warming.