todofwar

Service module for HAVOC, same principal as the Mars mission, at least according to wiki orion is meant to work with a habitat unit and possibly other modules such as a lander. Orion on its own isn't meant for deep space exploration

HAVOC, but that's because I'm a little too obsessed with Venus. I think the problem is we have no direction except Mars, and there are many more hurdles than just the ship to Mars to solve. To me HAVOC looks more likely to happen sooner and backers of the project have said it could be a test run for Mars in terms of long distance manned flight.

http://solarsystem.nasa.gov/news/2016/05/17/europas-ocean-may-have-an-earthlike-chemical-balance Not entirely sure what they mean by this, chemical balance basically means chemistry to me but I'm not a planetary scientist. They say it means life is even more likely than before.

What the hell is hydrogen monoxide? HAN is also a solid, so you need it in solution unless you mean to have this be an SRB. It's highly soluble in water, but I don't know if it would be usable as a saturated water solution. Edit: Wiki says they bind it to oligomers so it can be used as a liquid. So basically it's an ionic liquid. Might work, don't know of anyone mass producing the stuff. Also, as I suspected it's colorless, not sure what that lady is working with, looks like she's getting ready to run a mass spec or something so I doubt that is a HAN solution.

I'm guessing that's why they need such large fins at the base? Otherwise the shape of the shuttle would screw with maintaining a good launch trajectory? Also, this whole project has only been $14 million so far. Granted, until they have the working model we can't give them too much credit, but seriously they are masters of cost efficiency. Watch out SpaceX.

Especially once you add in driverless cars to the equation. I'm betting on a network of electrical driverless Ubers that you use with a subscription fee instead of insurance/gas. Of course, road trips go out the window, which will be unfortunate because those are nice ways to see the country. But again, it's not all about energy sources, and many batteries (most?) actually have organic solvents for their electrolytes.

And of course even in areas with tons of renewable energy sources like Iceland you don't get everyone jumping on electric cars because of issues with charging times and expensive batteries. I think the future of transport will be some kind of liquid fuel since gas fuels are a bit too dangerous. Gasoline is quite nice, surprisingly difficult to ignite yet energetic when you do ignite it, stable enough for storage for months, energy dense, doesn't corrode components, honestly if we can cap the carbon cycle it will be the best fuel around.

An ongoing problem sadly. You don't need to seed the ocean with iron, nitrogen is the growth limiter there. Runoff from farms has made algal blooms so large you can see them from space.

Which requires carbon sources. The foundation of the chemical industry is readily available feed stocks. Organic doesn't mean the same thing to chemists that it does to lay people, organic just means you have carbon (or carbon-hydrogen bonds by some definitions). In order to synthesize these kinds of compounds we're going to need a renewable supply of feedstocks. Once oil is replaced entirely, coal tar will cease to be economic to go after because it comes with tons of hydrocarbons that are now nothing more than a pollutant that has to be sequestered somewhere. Things like methylene chloride, THF, ethyl acetate, acetone, and acetonitrile which the synthetic chemists in my lab go through by the gallon will become horribly expensive soon unless we solve the carbon problem.

It's not just about energy though. Lubricants, dyes, plastics, pharmaceuticals, all require petroleum. Hell, even acetic acid is primarily petroleum derived. Now, if we stop burning all of it our current reserves may carry us for a while, but the lower margins on those products may very well make other means of getting carbon more attractive. Currently, as crazy as it sounds, the renewable and biodegradable plastic industry is horribly unsustainable. We're tearing down Madagascar for those compostable spoons everyone loves.

So get a solar powered pump and compressor. Or hope membrane research pans out so you can even let wind drive a fully passive system that separates your components for you. Plants aren't the most efficient, they need energy to run their own systems and the cellulose you get is not a good energy storage system because getting energy out of it is not trivial. The other issue no one talks about is water. You need tons of water to grow plants, most of which you lose as runoff. You can set up your CO2 harvester in the desert and pipe it elsewhere with access to water for reduction to methane or other products.

@p1t1o @shynung What I meant was using plants as your atmospheric harvester would not necessarily be as efficient as something that harvests CO2 directly. So plants are not a carbon source, they are a method for harvesting carbon from the atmosphere.

Except those biological sources are just concentrating from the atmosphere, so your ultimate source remains atmospheric.

@wumpus @magnemoe It's a two part problem. People are pumping too much water out of the aquifer, with parts of Florida being in a drought much of the year. This lowers the water table, which lowers the land but also disrupts the underground water flow. At the same time you have sea level rise. At a certain point, water pressure will flip and salt water will begin flowing in to replenish the water we pull out of it. Since water will continue to flow in from the north of the state, this won't be an overnight cataclysm but over time the water will become unusable for agriculture.

The siemens cycle requires energy input, but it is the best method for large scale gas separation we have at the moment. I know a couple of people working on specialized membranes, which is actually one of the few parts of nanotechnology that's not completely overhyped bs. Those would be the best bet if someone could get them to work. Once you have the CO2 the question is how to reduce it. I've seen photocatalysts in the literature that can convert it to HCO2H, and maybe a small amount that can get to methane but the efficiency is low.

The real risk to Florida is the porous rock means once sea level gets higher than the water table, all the groundwater becomes saline. So, the Florida aquifer goes away, and the state becomes essentially a desert.

I wouldn't put too much money on any kind of biofuel. A good analogy would be the Haber Bosch process vs nitrifying bacteria. Haber Bosch wins in terms of efficiency and atom economy, and its a completely synthetic process. "bio" is a nice buzzword but really chemists can probably come up with a better system (not something I say often, but it's not like you need elegant natural products for your fuel source). So, using some solid state catalysts we will eventually be able to store our energy in hydrocarbons, but the real question is will that be better than other energy storage means out there? Fuel cells are much more efficient, one thing that I haven't seen mentioned is that all these fuels are still being burned, which has a hard upper cap on its efficiency less than 40% no matter what you do. So eventually you will want to get the energy out electrochemically rather than through combustion. Hydrocarbons have the problem of needing multiple carbon carbon bond cleaving events. Not easy to do. So I would say either hydrogen or methane/methanol would make the best energy storage system until someone gets sodium sulfur batteries to work (not efficient, but very very cheap). Now, even if not useful as a fuel source, eventually the price of oil will become high enough that harvesting CO2 for other value added products (pretty much everything with a carbon in it is petroleum derived) will be economical. Another fun area of research, because there are some things which we still can't make at scale. This is the area that biopetroleum can really help out with, but it will probably involve cramming a bunch of ag byproducts into a canister and heating it under very high pressures for a few days to make coal tar that will be separable into useful components.

There are chemistry labs all over the world working on this very problem, some of them more successful than others. You don't need the extra step of going to CO acyually, plenty of catalysts get you there directly from CO2. But the big reason no one does it is we drill for oil for the energy it gives us. These reactions you describe are all uphill, so you will need an energy source to drive them. You're limited by where you get energy from, either nuclear or renewables. So really this is about energy storage, and while yes hydrocarbons make a great energy storage source, you're competing with hydrogen, supercapacitors, and batteries. Currently the others are easier to work with, but long term it would be nice to take advantage of all the existing petro infrustructure.

I read an interesting article talking about how the storm troopers helmets made them at a serious disadvantage. We have an innate desire to not kill people, so seeing your enemy's face makes it harder to aim at them. The storm troopers dehumanized themselves, so it was easier for rebels to shoot at them then vice versa.

If only there was some kind of software or game an amateur like me could use to demonstrate what I mean. Oh wait! Last photo ended up first for some reason, but basically the idea is you fire the outer two boosters, then disengage (I have to disengage with them still running to avoid collisions with the tail fins on the main craft) and use the center ship to reach orbit and deliver payload. Then you fly your boosters and main ship back. My thought was your overall design could work with this concept rather nicely, especially if they could land like sea planes and avoid the need for an extra jet engine and enough fuel to fly back to base.

As was mentioned, liquid nitrogen is used to insulate liquid helium, and the liquid nitrogen doesn't freeze. Clearly there's an easy way to do this.

I think the scenario is more it lands and everything seems fine but one of the kegs fails after someone has come on deck to secure it/inspect it. I don't have much experience with explosives, but I'm going to go with dive into the water. Even if you were on deck you'd probably be fine unless some burning fuel splashed on you, humans are mostly water which gives us a nice heat capacity

While we're on the subject, in the Martian movie there is a seen where they are floating in the 0g part of the Hermes, and then reach the center of the rotating part and just magically start accelerating down one of the shafts towards the parts of the ship that had gravity. Pretty sure that's not how centrifuges are meant to work. Also, the Hermes in general seemed a bit too big, I doubt NASA would provide such a nice lounge and gym, maybe as an inflatable but the Hermes didn't look inflatable.

I think this thread has strayed a bit from the original intent. I should have said, does science need to be falsifiable? Proof is a weird concept, I think Descartes did a pretty good job showing that proof is not always attainable. But in the end, for something to be science and not philosophy it needs some kind of concrete statement about the universe that can be proven wrong.

Science can sometimes be defined as the misunderstanding of statistics unfortunately. In the end basic research is funded by getting results that are definite, even when claiming a definite result is not always appropriate. People chase the all important p value and publish once they get below a certain threshold, but aside from the fact that this is not what p values are really meant for you can always adjust your criteria for throwing out data points until your p value is low enough. It gets worse as you go from scientific journals to pop sci, a paper showing a correlation between a certain gene and a certain phenotype becomes x gene causes y effect, when no such causal relationship really exists. But all this still involves falsifiable hypotheses, so it remains scientifically valid and the next scientist can come along and get credit for disproving a theory with a better p value (or slightly worse p value, doesn't seem to matter to the all important journal editors/grant reviewers).