AckSed

There are some initiatives to make a bioregenerative, fully-closed life-support system: ESA has been refining a bacteriological-technological system, MELiSSA, for years while NASA founded CUBES in 2017 to study genetically-modified microorganisms as part of the LSS, with an eye towards food, therapeutic pharmaceuticals and bioplastics, with oxygen as a side-product. The atmosphere, and the potential dust and soil and mould problems seem to be shoved to the side with, "We're working the food and waste problem! Hell with it, the ISS system is Good Enough, use that." Personally, I think a partial open-loop system that recovers water, nitrogen and heat, bubbles the waste atmosphere through a supercritical water reactor to sterilise before venting, and takes in oxygen from the regolith electrolysis and/or CO2 electrolysis would also be Good Enough. Perhaps something like activated carbon could be produced from the left-over carbon, as it's used in an extruded form to filter noxious odours and chlorine.

Impacting at 2% c, though... that's when solid matter stops being matter and begins to approach plasma. Maybe even fusion fuel. No idea how you make a crasher stage for that. But to bring it back, the key here is to send a train of the presumably mass-produced probes, passing through the focal point one after the other.

To paraphrase a certain spaceman: Spaceplane! Spaceplane! SPACEPLANE!

Son of a booster, they did it.

Parker Solar Probe about to kiss the sun full on the corona for the first time: https://arstechnica.com/space/2024/12/were-about-to-fly-a-spacecraft-into-the-sun-for-the-first-time/

Geothermal might work - in the right place. The Cerberus Fossae has all the signs of an active magma plume the size of the United States underneath it: https://www.sciencedaily.com/releases/2022/12/221205121545.htm Even if you don't use it to generate power, boring down to tap it for hab heating and factory process heat is viable, as there are companies that make heatpumps for these applications. Ground-source heatpumps: https://www.kensaheatpumps.com/is-a-ground-source-heat-pump-right-for-you/ Overview of steam-generating heatpumps of various types: https://www.sciencedirect.com/science/article/pii/S0196890423012281 ---- Regarding ISRU batteries, there are battery chemistries of differing complexities and capabilities. The most basic would probably be nickel-iron, as popularised by Edison. Good: very tough and long-lasting, easy to make. Bad: lose charge faster than other chemistries, uses water and sulphuric acid as electrolyte. Lead-acid is similar, but slightly better. Lead-mining on Mars is probably a no-go, though. Molten sodium-sulphur or NAS batteries are a small fraction of grid-storage batteries on Earth, and an early electric car used them as well, because they are simple to make and use readily-available materials: steel, aluminia, elemental sulphur, sodium metal. The show-stopper is that you have to keep them hot with insulation and integrated heating elements. Not so bad on Earth, more difficult on Mars but not impossible. Personally I'd use vacuum-insulation panels or, failing that, basalt-fibre mats. Other molten-salt or low-melting metal chemistries are possible: https://en.wikipedia.org/wiki/Molten-salt_battery ---Past this point we move out of possible workshop or small factory bootstrap construction and into needing to import factory equipment.--- Lithium-iron phosphate (LFP) is the current champion of grid storage, and the elements can be obtained on Mars. It's probably even easier to make the synthetic graphite from the readily-available CO2. The electrolyte and the water used is a problem, though. Sodium-ion batteries are a much newer thing, but already attracting attention for the availability of the base materials and the possibility of solid electrolytes. Lower energy density, though we don't particularly care if it's being used for stationary storage.

Found the paper: https://digital.library.unt.edu/ark:/67531/metadc1070838/

I read the entire thing. Man, I think I experienced roughly the same feelings reading it: glad you had the opportunity, wincing at the mess-ups. I sympathise with feeling out of your depth at uni, though not to the extent of working on hardware that was made to be launched. All I did was a BSc in Internet Computing circa 2009, and my ill-chosen final-year project nearly broke me. (Don't choose fuzzy-logic when you barely know how to make a database.) I would like to hear "How not to design for assembly" next.

Tiny payload ready for launch on massive rocket: https://www.blueorigin.com/news/blue-ring-pathfinder-payload

The water collected after passing through the catalyst has enough ammonia to add to the plants to supply the nitrogen they need. So if you had a drip-feeder or hydroponics mister for the plant's roots, this could be added to the apparatus. The Nafion polymer is, surprisingly, the pricey part due to its production cost.

Hang on, could we use hesco bag construction? Very quick, very simple, flat-packed cubical fibreglass bags made to be filled with dirt to construct walls. Combine it with locally-quarried stone beams and pillars, or a composite inner frame, plus an inflatable pressure vessel inside, more overfill on the top, and you have a home. More whimsically, I'm imagining triple-glazed windows inset into the sides that double as 1 metre-thick water tanks.

It actually works slightly better in warmer and drier areas, too. And the power requirements are minimal compared to the Haber-Bosch process; if you wanted, you could use ambient wind instead of a fan or spray, and maybe passive cooling to condense the enriched water.

Efficient, yes. Nice to live in? Hmm. One design I saw for a Mars hab was to, essentially, have a sod regolith roof atop a bungalow, and use mirrors to reflect sunlight into the interior. It'd need sturdy construction and maybe cleaning of the mirrors after a dust storm, but if you're making and shaping steel and glass and plastic on-site (and we could and should) it's no hardship to build tough. We have robots that brush dust off solar panels on desert solar farms, so those could be adapted for the mirrors.

Stanford University researchers have created a process for making ammonia from thin air, at ambient temperature and pressure, by utilising an iron-oxide/Nafion catalyst and the properties of water microdroplets: https://www.science.org/doi/full/10.1126/sciadv.ads4443 It goes like this: a fan draws air in through the air filter, through the catalyst, and onto a chilled condenser plate, where the ammonia-enriched water condenses and drips down into a holding tank. They achieved concentrations of ammonia (120 micro-mol/L) on-site, suitable for some plants. By upscaling a bit, recycling the captured solution and passing it through zeolite filters, then washing it out with a bit of hydrogen chloride, they increased it to 1.4 millimol/L. The experimental setup is notable for how low-energy and low-tech it is:

Vertical farming? This lets me bring up the BioPod, a proposal for a self-contained greenhouse that can work on Earth, in orbit or on Luna or Mars. Flashy site aside, this is a legitimate effort that's been steadily developed since at least 2018.

I think it's akin to the Apollo Applications program, had it not been sunk prematurely by the cancelling of Saturn V in 1968. A true, in-orbit refuellable space-tug would make its resemblance complete. It's not 1:1 - a lot of the hardware and expertise is coming from CNSA or its satellite campuses/companies, farmed out to private entities who develop them. It's like if NASA was also a military aerospace contractor... and MIT.

Small Business Innovation Research/Small Business Technology Transfer (SBIR/STTR) grants may play a larger part in getting and staying on the Moon: https://payloadspace.com/nasa-cozies-up-to-industry-with-2025-sbir-plans/ So, though the awardees typically display the "valley of death" where after stage 2 funding finishes, about 1 in 6 reach Stage 3 (commercialisation), this says (hopes) that they have a better idea how this year. One of them is outright propping up entrepreneurs and commercial companies with SBIR Ignite. Now, it's no free ride, they have to reach certain benchmarks, but this lets companies access NASA technology and patents when they are just starting. This year it's: Aviation-Ready Electrical Energy Storage for All-Electric or Hybrid Electric Aircraft (heavy drones and certification for such) Leak-Free Cryogenic Valves and Quick Disconnects (valves and disconnects that will work on the ground and in space) Decision Support Tools Leveraging NASA Earth Science Data (processing all the data under the Earth Science To Action initiative)

The thing is, an organic, livable city on Mars starts to bring up questions of "What is perceived as an organic, livable city on Earth?" In my opinion, it should not be based around the car. That, and zoning laws, isolate people inside their castles, moated by your lawns, and bubble you in your pickup truck. It is ridiculous how large American houses are. Public transport should be cheap & available. Walkable streets, large communal spaces, modest living quarters. That's part of the recipe. Not the whole one, I don't have all the answers, but part of it.

Can it be done with mathematics? Going to try. Random site I found says: For the dome with 11.3 m diameter, 5.65m radius and 100m2 of floor area, and assuming radius = height, that's an area of 200.58 m2. Punch that in... Water dome on Mars: 1000 * 3.72 * 1 * 200.58 = 746,158N/m2 Water dome on Luna: 1000 * 1.625 * 1 * 200.58 = 325,943N/m2 On Mars, the temperatures measured in e.g. Gale Crater can range from 20 deg. C all the way down to -84 deg. C... in summer. In winter, knock 20-30 degrees off each of those. Mars gets cold. The dust storms are no fun, either, blocking up to 99% of light. Water stays ice, most of the time. On Luna, it ranges from -173 deg. C to 116 deg. C at the equator. The water might boil.

https://www.thehindu.com/news/cities/bangalore/scientists-and-astronomers-meet-at-raman-research-institute-to-explore-moon-as-vantage-point-for-studying-the-universe/article68948159.ece

Moon Monday Report on the Chinese-hosted Galaxy Forum. Featured former NASA astronaut Donald Thomas as a speaker. Goals for International Lunar Research Station (IRLS): Learn about our Moon’s evolution & structure; Conduct lunar-based astronomy for doing cosmology and studying habitable exoplanets; Observe the Sun and Earth from the scientifically unique vantage point of our Moon; Conduct lunar-based experiments like studying plant growth. NAOC/CAS target launch year for the proposed lunar orbital satellite constellation called Discovering Sky at Longest wavelength (DSL) is 2027. It will have a 'mother' satellite and eight trailing 'daughters'. Thailand's NARIT, one of the partners in the IRLS, has ambitions of launching a Lunar Pathfinder nanosat, possibly to be launched on a Chinese rocket. The slide opposite detailed NARIT's 40m radio telescope, which will be used to track spacecraft in conjunction with China's own Deep Space Network: a 25m one in Xinjiang Astronomical Observatory, Nanshan, and the massive 65m one in Tianma, Shanghai.

With regards to size, the psychological advantage of a wide-open space cannot be overstated. Here's a company that makes 10-metre in diameter dome tents, 5metres high, with 80 square metre floor space: https://www.domecompany.com.au/dome-sizes/the-10-metre-dome/ As you can see, it's pretty big, yet it can be loaded on a pickup truck and assembled by hand. A 100m2 dome will be bigger still (11.3 metres in diameter), but you're right - it's probably good enough to give that sensation of space, air and light that people need if they're living in regolith-protected burrows. Part of me also says that geodesic domes may be the most efficient structure, but the whole craze of dome-building in the 70s and 80s made the drawbacks when using them for living space apparent: your appliances and furnishings have to be custom-made, there's 'dead' space where the walls meet the floor and the acoustics are great for a concert hall, poor for privacy: https://earthtodome.com/2017/01/19/geodesic-dome-homes-the-good-the-bad-the-awesome/ However, there should absolutely be a park or botanical garden that isn't a dome. Think something like the Crystal Palace. ---- I can see one advantage for building domes and structures on Mars that Luna doesn't have: the atmosphere. We know that Mars has elemental sulphur and enough iron for reinforcing steel rods. That says to me you could use sulphur concrete, and the atmosphere and much milder temperature range means that the binding agent - sulphur - won't sublimate off. If you wanted to make normal cement (or edge-cases like magnesium cement or zinc oxychloride cement) there's the materials for that, too, and they will be able to absorb carbon dioxide as they crystallise. Probably a waste of water, but you could do it. There is also plentiful carbon dioxide and some water; with chlorates also being a waste product when cleaning Martian regolith for use in greenhouse soil, that says to me 'PVC and polyethylene plastics for a vapour barrier and maybe even greenhouse windows'. That's not to say Luna doesn't have its advantages. You're right about the Human Flying Dome. The Menace From Earth got it right the first time by making an attraction that everyone wants to experience, even the natives. It'd also be a good way to harvest water and carbon dioxide from visitor's breath. Tourists will go. "You mean it's free?" "Well, you've already paid for the ticket and brought water, food, your, er, waste and carbon, so yes." The visitors will then experience the extra-splashy 0.1 G pool (don't ask where the water came from), the human Wall of Death, the human loop-de-loop track and the jungle gym. Though you'd have to have spotters who could tell when people overextend themselves, as they may feel light, but they are still overcoming inertia and working up a sweat - bad for the rich and unfit. Edit: I had a brainwave: Lunar kung-fu. Re-enact The Matrix and old wuxia - in real life! Wall-running, diving through a window from 5 metres away, impossible rolls and flips, mid-air sword duels - you too can feel like a superhero!

https://payloadspace.com/ukrainian-small-launcher-finds-refuge-in-the-us/ So this is interesting mostly for Promin's rocket technology - it's autophagic. That is, it burns hybrid solid propellant, gaseous oxidiser and the tanks themselves as fuel, making for a tiny single-stage rocket that can launch a sub-orbital payload of 20kg or 3kg to orbit, and doesn't need to shed mass by staging.

Less of a honk, more of a gentle fvwoof. Slick.

Indeed. For the tradeoff of having to wait an hour for each launch, working three shifts and assuming you have 1 cubesat equivalent per yeeted launch vehicle, a high-inclination LEO constellation of 22-24 satellites, say like Planet Labs' SuperDove earth-imaging cubesats (5kg each) could be launched within 24 hours. A working 6-day week of 2 shifts at 15 shots per day? 90 satellites. We might end up with a new metric: kg to orbit per hour.