AckSed

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.

SpinLaunch is still around, and making hardened cubesats: tl;dw A dash of glue, a few reorientations of components and a 1U cubesat can survive 10,000 gravities.

The Planetary Society's hopeful take on the pick, including an interview from last year: https://www.planetary.org/articles/who-is-jared-isaacman

Podcast interview of Slovenian photographer Matjaž Tančič, who has lived in China for ten years and has an explanation of ordinary life for the Chinese and the attitude in China towards space industry. As always, I go to "Show Transcript" and read: tl;dr You can go from photographing rocket launches to tribes that haven't changed their practices for a century in the same country. Shanghai more cosmopolitan. Practically a cashless society. WeChat Pay and Alipay does everything. In the larger, newer cities there are drone deliveries where the delivery guy sends a bot into the building and it comes to your door. It's very safe for the average citizen, because the consequences of committing a crime and losing access to the network are dire. The little old ladies sitting on a street corner wearing a red band are the eyes and ears He shot a Mars simulation, and a rover that was inspired by camels, being tested in the Gobi Desert. Just after that, he flew to Los Angeles for a holiday and on a whim, he googled "Mars exploration Los Angeles" and found not one or two hits but hundreds: Mars architects, Mars farmers, Mars chefs, Mars fashion designers, Mars psychologists, Mars urban planners, Mars watch maker... He decided to stay. These entrepreneurs were also concerned about using these technologies to assist with problems here on Earth. Dr Susan Joule (spelling?) is developing a VR avatar, telling medical staff where to cut and so on, for remote operation on Mars and Earth. These could be air-dropped during natural disasters. Armenian watchmaker Garo Anserlian, with a shop near JPL, modifies watches to run to the Martian day - the Sol - and they were worn by several engineers working on Mars Rovers, who worked to the sunrise and sunset of Mars, when the solar panels gained/lost power. This inspired his exploration of New Space: in the 60s, it was very much a race of white males to go to the Moon, take a selfie and plant a flag [reductive much? But not wholly wrong]. Here, now, it's a bunch of people all over the world - China, USA, Japan, South Africa and Europe - who will never get to go to the Moon or Mars, but are working on smaller pieces of the larger puzzle: growing food, what clothes to wear, psychology, what kind of lights should be in the base, and so on. Because a Mars expedition is going to take a while to get there. The Slovenian (then Hungarian) Herman Potočnik designed the first spin-gravity space station, detailing it in a 1928 book published in Germany.

The MAVEN satellite and Hubble Space Telescope measured Mars' atmosphere and found that the solar wind and sunlight (which varies over the Martian Sol by 40%) provided the last kick needed to strip the water out: https://science.nasa.gov/missions/hubble/nasas-hubble-maven-help-solve-the-mystery-of-mars-escaping-water/ Then I remembered the electrostatic shielding simulations performed by JPL and JSC: https://arstechnica.com/science/2024/03/shields-up-new-ideas-might-make-active-shielding-viable/ tl;dr a set of stacked charged plates arranged in a cube and Sputnik-like charged rods at each corner shape the fields such that 50% of solar charged particles are repelled, but plasmas pass straight through, reducing the charge needed from 60 million volts down to 1 million, and power required for a crew hab down to 100 watts. Scaling this up to the size of a planet would be a job of work, and would only slow the bleeding, but it's one component of the bandage. Fake edit: I searched further, and people have suggested that an artificial magnetosphere at Mars-Sol L1 would shield it enough that the temperature might rise anyway once the rate of loss is slowed: https://phys.org/news/2017-03-nasa-magnetic-shield-mars-atmosphere.html

To cap it off, here's a relevant video from Scott Manley:

Your three-letter acronym to search for is PMD or propellant management devices. I also found "CRYOGENIC POSITIVE EXPULSION BLADDERS" by Raymond F. Lark, Lewis Research Centre in 1968:

The LUNA regolith simulator is up and running. First test: banging rocks together. Second test: dragging sensors over the rocks.

Theoretically, you could make a chemical explosive inertial-fusion warhead by means of a set of very precisely-placed staged flyer plates backed with explosives, and a capsule of fusion fuel at the end (scroll down): https://www.projectrho.com/public_html/rocket/spacegunconvent.php

Besides, floating balloons are out, floating carbon-composite hexagonal tiles making a floating surface are in: https://www.researchgate.net/publication/359228323_Cloud_Continents_Terraforming_Venus_Efficiently_by_Means_of_a_Floating_Artificial_Surface

NASA have finally told the press how the divots in the Orion heatshield happened: the material was less permeable to gas than the original Apollo Avcoat and the permeability varied across it. As it cooled from the initial heat of the skip trajectory, the gas generated inside in many of these places couldn't escape. When it was heated again with the final re-entry down to the ground, the gases expanded and material broke off in the chunks we see. Engineers found a total of 100 spots where the material broke off in ways that it wasn't supposed to.

Actually the plan of the 'backyard space program' J. P. Aerospace. They call it the Dark Sky Station, and it's meant as a waystation for the balloon to upper-atmosphere to transfer payloads to the hypersonic balloon. Yes, I know, but it looks cool:

I think someone calculated that an empty rocket stage could just about float at pressures and temperatures within tolerances for that stage: https://selenianboondocks.com/2013/11/venusian-rocket-floaties/ Starship, being bottom-heavy, designed to skydive and mainly made of stainless steel, might just be able to float and survive. If it doesn't burst from the pressure.

Are the water sprinklers on the drone ship a new thing?

Both this and Blue Alchemist are encouraging, but both use regolith simulant: sorted and graded Earth volcanic tuff and crushed basalt. Lunar dust has two unique properties. The jagged nature of the particles can be approximated, but the other... can't. Namely, that it melts with a modest amount of microwave energy. I'll just quote the paper "MICROWAVE PROCESSING OF LUNAR SOIL" by Lawrence A. Taylor and Thomas T. Meek: Dr. Taylor knows this because Dr. Meek tested it with actual soil gathered by Apollo 17. Putting aside for the fact that you should never, ever, under any circumstances heat water for your tea in a microwave *shudder*, the paper proposes grading a surface like dirt on Earth and sintering either a continuous slab to make a road (apparently a normal magnetron-generated beam penetrates and sinters to half a metre, and melting the top surface completely to glass can be done with a second pass) or using magnets to gather particles with more iron and sintering road slabs out of it. You can even gather the solar-wind particles released: hydrogen, helium (including He3), carbon and nitrogen among others. If glass can be made that easily, it's probably a good way to make foundations, structures, radiation shielding, glass fibres... even a substrate for a solar cell.

If I might straddle both camps here, I believe Exoscientist is working off an older, long-held dream of the Apollo Applications Program, and Constellation, and now Artemis: here is something that could lift all the things they dreamed up, right now, if the ones making it deigned to make a simple modification. The frustration is real. The Starship troopers (sorry, not sorry) have lost their heart to reusable second stages, which seem more real with each flight test that reaches the water, and are more trusting/hopeful that it will pan out. The excitement is real. Who wins? SpaceX decides. Myself, I think if it becomes necessary, an expendable booster and Starship would launch in a few months - if they needed it. That's the thing about their workflow: modifications are easier when you have completed ships, and they have the expertise to change software and weld steel to suit.

Ooh, that looks shiny. I do wonder: has the boat has been missed here, or are they hanging on to the boat with one hand? 3 tons to LEO is not too shabby for single satellites, but constellations are 'in'... I'm being silly. Obviously, this enables downmass as well, and satellite recovery and refurbishment. If they license Canadaarm, we'll know I'm right.

Man, they look ponderous from the ground, but from the air they zip off.

The key points Zubrin makes about the motivation of the first Mars settlers and the ones that will be successful are: They want to be free, to retain their identity. Commercial reasons will be there, but the draw that makes people move all the way there to live will be ideological. It's the same reason, the same motivation for immigrants today, with the same debates of "Who is worthy?". Here, though, there's no government to say, "You're not getting in"; The settlers that make communities and grow will outcompete the outposts, the indentured workers and strip-miners with limited population; While it will be more difficult, they will be able to extract the resources of the new land just like the American settlers did with wood, coal and iron; Worker shortage and an educated populace will spur new developments, new solutions to problems we haven't considered yet. Zubrin points out how steam engines were improved upon in American trains and the improvements fed back into Britain. (Personal bet: something like Red Mars where biotechnology engineers a solution to either DNA damage and/or mitigate the effects of low gravity.); The risk of radiation is overstated. He also makes the case that modern humans spend 80% of life inside, so living inside a buried habitat on Mars is not going to change much: