farmerben

Within a few years we could have a solar collector near the south pole in perpetual sun, 20 km away from the known ice fields. Human exploration will include looking for lava tubes. And then figuring out if lava tubes can be sealed to create habitat. One method of searching for lava tubes is to set up a grid of seismometers and set off some dynamite. That could generate an acoustic subsurface map.

On the Mississippi river the towboats do not stop to refuel. Tender boats come out and refuel them with diesel in motion. I wonder to what degree you could do the same thing on batteries? The big towboats use about 10,000 kW of power.

Given that weight is a big issue and the square cube law. This could be a partial solution for ships.

What is the difference between crushed glass and sand? Can you use them interchangeably in concrete? If you were to spread crushed glass on the environment, would that be worse than spreading sand?

Another idea. What about using wood? Very little wood is "wasted" at saw mills, but more of it goes into fuel than engineered products. The engineered wood products require process heat after all. Anyway when you saw lumber anywhere from 25-50% of it ends up as wood chips and they will oxidize eventually one way or another.

Do staircases work in Martian or Lunar gravity? So do you want much larger steps to leap up to, or are staircases governed by the flexibility of the average person and need to be the same size?

i made it to lvl 8. not easy

Don't waste my time on another LEO station if it doesn't have a centrifuge.

It looks like they had plenty of extra fuel, albeit the mission was unloaded.

The top fins on starship took reentry damage. Good thing they are steel.

Competitors should be designing payloads right now. Think about how cheap the next Mars rovers will be. It's time to go find some lava tubes.

I guess it would be bad to sweep dust out an airlock, future collision hazard and all that.

Given the shortage on nuclear development on land, I see no reason to prioritize it on the water. Everything on boats break much more often due to the constant wave motion. Actually dirty maritime fuels reduce global warming due to the aerosol effect. https://www.livescience.com/planet-earth/climate-change/cutting-pollution-from-the-shipping-industry-accidentally-increased-global-warming-study-suggests

The chances of a nuclear accident are too high for this sort of thing. Meanwhile an electrical propulsion system that takes up less volume than an ICE is not necessarily better. What matters is the weight and the amount of extra water displaced. The engine rooms on conventional ships are huge and mostly empty space. Shipping containers are typically loaded to 25 tones or less. On US roads that is about the maximum weight without special permits. That's about half full with lithium batteries. Cargo ships also like to load the heaviest containers at the bottom and empties on top.

I'm not sure what tools. I've picked up tidbits like they used sharkskin for sandpaper. The red boats above I think are modern replicas of boats that were built in the late 17 or early 1800s. Even if you assume metal axes and metal chisels, it's still pretty impressive. For that matter the totem poles of the pacific northwest are impressive carvings if you wanted to make one without metal tools. One source I read said Europeans used to lash hull planks together with leather until the Vikings invented the technology of nailing planks to the hull. The Romans appear to have used mortise and tenon (peg or biscuit) joinery to bond planks edge to edge. Anyhow that is an astonishing number of skilled man hours that go into building a ship, akin to building a temple. The Viking clinker method sped things up considerably. Metal axes and knives were the first things traded by early Spanish explorers. One preferred method for introducing yourself was to hang a tomahawk in a tree some distance from a village. The next time you return sit still under that tree with a blanket full of trade goods. Indigenous cultures almost universally understood and wanted to trade.