farmerben

Why did the upper stage blow? Was it a heat shield - reentry failure?

The process of adaptation and evolution can happen much faster than most people realize. Most domestic dog varieties are thought to be less than 500 years old. Similarly most domestic food plants are shaped by human hands to the point of being unrecognizable from their wild cousins. We now have a biotech revolution which basically allows us to cross genes between organisms that cannot mate, and to delete genes. If or when we find a bacteria that survives on Mars it will be an important discovery. Somebody could use it as the basis for other engineered lifeforms to produce oxygen, etc.

Yeah. The only good stream I've found is Ellie in Space. Who else is streaming?

The whole concept of species is a man-made distinction. Sort of like the rules of English grammar, they work most of the time except for the exceptions. Most people have heard of lion-tiger hybrids. According to Wikipedia a female liger reproduced with a lion producing a liliger which was feeble but survived. Sheep and goat are not only different species, they are different genera. Crosses are usually stillborn or infertile, but not always. https://en.wikipedia.org/wiki/Sheep–goat_hybrid

Maybe the vacuum resets are not perfect and bacteria survive in the soil. The resets will be able to control invasive plants and insects should you ever have a problem. The opposite approach is the one I take. Utilize maximum bacterial diversity to consume any malignant organisms. In the early 20th century a soil scientist named Ehrenfried Pfeiffer collected compost and soil samples from farms and compost piles around the world, and eventually added all the samples to his own compost. His collection lives on, biodynamic farmers use it.

Chickens who are not starving will completely ignore house flies and ants. I've watched enough to be sure. They must be unpalatable or something. They will eat the hell out of grasshoppers, but why you would introduce or keep these three insect species sounds like a bad idea to me. I imagine livestock could be moved through airlocks and occasionally decontaminated just like the humans. Most of the domes would be insect free most of the time. Pollinating bees would be handled like other livestock. It would be a priority to have parasite free bees. As near as I can tell bees are not symbiotic to any other insects. Another question though is if you value insects and other lifeforms for their own sake, even when they produce no value and consume resources. I would say no for most insects on Mars. Invasive plants might be zero problem at all if things are done properly. Invasive bacteria are inevitable, but spacing the bacteria could handle many potential problems.

Very interesting discussions lately in a couple of other threads about how to operate an agricultural system on Mars. One question that interests me is how complex the ecosystems need to be? Do you need soil microbes, fungi, and even insects? If so how diverse do you really want to be? I've done a great deal farming the old fashioned way and the biggest problem is competing with weeds and insects. I like the idea of being able to sterilize and restart your growing environment by just "spacing" it (removing the air for a while). Some food plants can definitely be grown in a sterile environment. But I would argue better food will be produced with compost and soil microorganisms. This can be done with very modest effort. Suppose we sterilize a 100m2 dome by "spacing" it. Then I think we could restart a active soil ecosystem with a few gallons of compost tea. If you are talking about more complex agriculture, you would feed all of your plant residues to animals like rabbits and chickens. That would bring with it a system that you cannot easily sterilize and restart. Eventually you will have problems with invasive species. The more insects and complex life you bring the more the invasive species problem will become manifest. It makes sense to me to have a network of semi-independent domes and to move products between them as desired. With some of the domes being periodically sterilized on purpose just to make the cultivation of annual plants easier.

Modern gunpowder is made of mostly nitrogen. Black powder has sulfur and potassium. The heavier the exhaust the slower it goes.

It might be garbage, but a lot of the stuff I read back in the 90's and early 2000's was probably worse garbage. The observations of the past 30 years are incredible. But, I'm of the school that the best science predicts something before observing it. Some have it the other way round.

https://space.stackexchange.com/questions/54476/what-is-the-isp-of-gunpowder-likely-to-be-could-this-table-be-right-can-it-eve These guys settled on about 90s for the ISP of gunpowder.

I don't have the equation handy, but it should be possible to calculate if you know the initial and final masses and the altitude it reached.

Hmmm. They might decide to keep their habitats at 1/2 an atm. That would be like living in Machu Pichu, humans can adapt to it.

I'm afraid you will require a small maintenance replacement air program no matter what. If you lose half your air to airlocks and active operations, and half your air to painted rocks that enclose a huge amount of space it would be worth it. The air flow rate through solid basalt is not very great to begin with. I mentioned vinyl because I'm optimistic you could mix it in two parts and apply it via spray gun in a vacuum. Polyethylene and Polyester are used more in food containers, i just don't know if they could be sprayed on. Once you've got a chamber 99% sealed, you could probably simply pressurize it and use any water and air based paints similarly to how they are used on Earth.

Wait. You're right the figures I quoted are for rockets where you convert most of the mass into propellant. Jumping 6 times higher on the moon is correct.

https://en.wikipedia.org/wiki/Lunar_lava_tube You can start where lava tubes already exist. Very interesting wiki page. Some of the natural skylights are as small as 5m, quite easy to dome over. The large 900m skylights would be quite difficult to dome over but not impossible.