Bill Phil

https://mobile.twitter.com/i/broadcasts/1nAKEzgVRPVGL

MechWarrior 2's soundtrack. Oh, man. That is some crazy awesome music.

Yeah they can be tough. Practice in the Jool system, and maybe get a mod to extend the time warp settings for interplanetary trajectories. What a gravity assist does for you is exchange delta-v and time. You take longer to get to your destination but you can do it with less delta-v. There are tools to help you plan assists, but you can just timewarp until you get encounters, using maneuver nodes to see how many orbits you have to wait. Then you do some maneuvers to get your trajectory to be what you want (or close to what you want). The best assist targets are the biggest planets/moons - Kerbin, Eve, Jool, Tylo, and Laythe. There’s a series of assists called KEKKJ (Kerbin-Eve-Kerbin-Kerbin-Jool) that takes you to Jool for very little delta-v.

Wait, what? Even when I was in “In School Suspension” (and for extended periods at that...) I was given lunch. Can they actually not give you food? Or are you just not going to be in the normal lunch area?

I don't really believe that. Yes there are problems that are bigger than they might be if we had less people, but there's no reason to assume that a lower population will inherently be better for the environment. For example, the United States represents 15% of all CO2 emissions (according to some sources) despite only having 4.3% of the global population. China is responsible for 28% of CO2 emissions and has 18.2% of the global population. And yet in many developed countries there's more forest and other similar environments than there were a century ago. Of course that doesn't make up for CO2 emissions. But the problem is not inherently one of population. And even if the population was stable at a much smaller size, if the economy continued to grow and the energy use of our civilization continued to grow then we would see environmental damage over time, and eventually the damage would rival our current damage on a global scale (but on a per capita basis it would be much more damaging). Lowering the population size is not a solution, I'm afraid. For one, many economies require a growing or at least stable workforce - this can be dealt with but that would take resources away from addressing world problems. I would argue that it is easier and more effective to address world problems with an expanding population than with a shrinking population. An expanding population gives the species a larger and larger pool of labor from which to draw upon. Of course it can expand too fast as well. I would also argue that meeting human needs are of higher importance than environmental issues. This is debatable, of course, and the environment is a major factor of human needs so preserving it is important even for that goal, so we should still do it. It turns out that humans don't live on that much of the Earth, and as the global population urbanizes more and more I suspect that most of the inhabited land will become more scarcely inhabited. So what's happening to all the land? Well, suburban sprawl is an issue that needs to be addressed, though I don't have a solution. And of course there are projects and a lot of industrial processes and other human activities on uninhabited land - so the damage caused by that needs to be minimized. I haven't read a thorough analysis so I don't even know what's affecting what, but we can find out and address those issues. Agriculture is a major issue - though advanced technology could change this tremendously. One major industry that affects the environment in major ways is the meat industry - however the damage could be reduced tremendously if cultured meat could be developed and delivered to consumers. This can also help with the rising demand for meat and has ethical benefits - no more slaughtering required to get meat. This would also free up vast amounts of land and could potentially reduce demand for Amazon Rainforest clearing, as over 60% of the cleared land is used for pastures, which would become virtually unnecessary if we adopted cultured meat. This would also free up the crops that normally go to feed animals, allowing for more food to go to human beings. More efficient agriculture could be developed - such as indoor multi-level agriculture, which could reduce the need for vast amounts of agricultural land currently used for raising crops. With isolation of the agricultural areas the need for damaging insecticide and pesticide can be reduced tremendously and highly efficient aeroponics could be employed along with optimization of the environment for the plants to massively improve yields. If fish meat can be cultured as well then the demand for fishing could be reduced, and the overfishing problem could be mitigated. Energy is a major aspect of carbon dioxide emissions. Currently renewables don't seem able to keep up with demand. Generally solar has a capacity factor of nearly 25% while wind reaches 40% averages. Meanwhile coal regularly goes above 60% and nuclear's average tends to stay at or above 90%. Not only this but the shorter lifecycles of renewable energy technology leads to other issues, such as a higher replacement rate. Add on to this the low capacity factor and much more capacity has to be installed than is demanded in order to meet demand. This means that renewables have hidden costs, not to mention some fairly nasty environmental effects - solar panel waste is known to be toxic (though this can be minimized) and since they have a higher replacement rate there would be quite a lot of waste that we would need to deal with. Space based solar power could work, though in the interim I recommend nuclear power. The main disadvantage of nuclear is its immense cost, which is well known. However much of this cost can be eliminated with proper project management and a more mature nuclear power industry. With advancements in heat engine technology (mainly by using supercritical CO2) efficiencies can be increased by fairly large amounts and costs potentially reduced (when compared to steam turbines). Renewables should be used but they need better energy storage solutions - one I've come across is referred to as PowerLoop, an idea by Keith Lofstrom (of Lofstrom Loop fame). This concept involves linked iron rotors undergoing electromagnetic acceleration through a track as a form of energy storage. Another advantage is that it can be fairly efficient at delivering energy over long distances. One major advantage over flywheels is that a PowerLoop system is not limited in the same way by the strength of the material. Another advantage is that as the technology matures it could be adapted for space launch as a LaunchLoop - which could provide benefits as well. Renewables are not quite ready (yet), though they can be and I would say should be used in conjunction with energy storage. However some areas can not use renewables, or not to the necessary scale. Where I live it is simply impractical. Nuclear has to be a part of our energy production (and it is for now). As such we need to have a varied energy grid. Transportation is another major issue. Electric vehicles show potential but they have problems as well such as the toxic materials in the batteries among other concerns. However South Korea has developed a way to charge electric vehicles while they drive on a road. This would require digging up and replacing all current paved roads to employ, but it is a potential solution. Hydrogen can be employed in aircraft but it has practical issues. Of course these can be overcome but it will be difficult to replace existing infrastructure. One fairly major aspect of shipping's environmental effect is its emissions. Some alternatives to the current propulsion systems include nuclear (though this could have issues, but may be more mature than nuclear power thanks to the US Navy), and potentially hydrogen-electric or hydrogen internal combustion. Another issue is that personal transportation is arguably too prevalent in some countries. A much wider and more effective/efficient public transportation system would be immensely useful, especially if it is all electric. And if that isn't enough then climate engineering may be necessary. This all almost completely theoretical, but it may be possible to engineer Earth to be better for us and the other lifeforms of this planet. Science and technology can give us solutions to most, if not all, of the problems we face while enabling humanity to prosper as a species and save the biosphere. Of course this is more short term in the grand scale. I sometimes wonder if our waste heat will ever grow big enough to rival the energy the Earth gets from Sun... If that happens I wonder if dynamic orbital rings could be used to suspend radiators in space around the planet to radiate the excess heat away. Now that'd be crazy. Imagine Earth with rings like Saturn - but these would have a practical purpose.

Well there are some ideas about dusty plasma radiators... those could be interesting and high performance.

I don’t think so. Building space hardware of any sort is difficult and will remain so for some time. Even if launching is cheap the actual spacecraft itself will likely be expensive. I don’t think space telescopes will rival the sheer size of ground telescopes for some time. I think we’d need a mature space manufacturing industry for that. Maybe not but even now there are quite a few 20 to 30 meter telescopes under construction. Quite a lot of astronomy is done with already existing installations so I expect the bigger telescopes to be very useful in the coming decades.

Breaking Ground added props. So that one.

Helium-3 is not plentiful on the Moon. At all. In fact, I've found that in order to extract Helium-3 you need to spend more energy than you can get out the fusion fuel. Not only that but lunar Helium-3 is counted in the parts per billion - as in Carbon Dioxide is more plentiful in Earth's atmosphere than Helium-3 is in the lunar regolith by orders of magnitude, and even then it's difficult to extract the carbon dioxide on large scales and we're living on this rock. Processing the Helium-3 out of the regolith is a difficult process. Lunar Helium-3 is not worth it as a fusion fuel. Though we are aware of other uses for Helium-3. Helium-3 is aneutronic when used with itself, but not fully when used with other isotopes of other elements - the reason for this being random fusion events between the other isotopes, such as D-D fusion when you want D-He3 fusion. The D-D events still happen releasing neutrons. H-Boron fusion has a massive Lawson Criterion and still isn't fully aneutronic, not to mention it can give off gamma rays.

Presumably we would have to be very advanced to be able to employ any kind of FTL drive. Not only would we have advanced theories to explain the universe but also extremely advanced computers. If we have a large number of telescopes (particularly large ones at that) across colonized space... Well, then I don't see a problem if you're just jumping within a galaxy. We can do surveys of the Milky Way galaxy and make predictions on future locations of objects. This will have uncertainty, and there will likely be regulations on low certainty vs. high certainty jumps. As humans expand across the Milky Way technology and infrastructure would likely continue to advance. Observation stations will be established that regularly deliver information about star systems and positions to the appropriate authorities where it can be accessed by travelers, reducing risk substantially across human space. Eventually surveys of the Local Group's galaxies will be possible and then intergalactic jumps will be carried out, likely by unmanned vehicles initially, which will then attempt a return jump. If it succeeds then it can report on the positions of certain objects within the galaxy. If not... try again. Of course we could just do incremental jumps using a daisy chain of jumpships between galaxies and just exchange messages, passengers, and cargo across at each stop. That way each individual jump has a lower risk until the other galaxy has been more accurately mapped. I wouldn't be surprised if expansion to other galaxy groups and even some nearby clusters could be done over time, maybe even the entire Virgo Supercluster... Redshift is a change in the wavelength/frequency of light - ergo it is an intrinsic property of light being changed. I would call it an intrinsic property of light from distant objects. Only works within a certain range of distances (on the intergalactic scale) and of course still has uncertainty.

Somewhere, out there, a new star has been born...

One can argue that we can’t hide period, given that civilization emits waste heat.

It’s not the hardware, it’s the logistics.

Boeing. Just, Boeing. And of course bad project management. But Boeing is putting a pretty large wrench in the NASA bureaucracy, not communicating properly with many NASA project teams among numerous other problems.