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This video discusses cast basalt as the most practical building material on the moon.
https://youtu.be/p230vGSqefQ
The same is probably true on Mars. Cast basalt is enormously strong in compression. Its tensile strength is described in the video as being 40% that of wood, presumably douglas fir or someother commonly used softwood timber.
Welding basalt with lasers doesn't appear to produce very satisfactory results. This is because high temperature gradient results in stress fractures within the material. One commentator suggested using epoxy glue to join components. This would work well if the components were smooth and closely fitting. The glue layer could be as little as micrometres thick. Unlike the moon, Mars has an atmosphere. The pressure is sufficient to prevent heavy molecules like epoxy monomers from boiling as they would on the moon.
I wonder what else could be made from cast basalt? Could we make machine parts from this material? Rails perhaps, with a thin steel strip taking the weight of a train wheel and transfering load to a cast basalt rail?
See here for a potential power source.
https://newmars.com/forums/viewtopic.ph … 59#p231959
It would be neat to have a reusable ITV that can be assembled from the payload of 1-2 Starship launches. We could say 1 launch for the basic vehicle structure. The second launch for propellant, reactor and consumables.
This paper is actually 3 years old. It discusses the use of lattice confinement fusion as a neutron source, driving fast-fission of thorium or depleted uranium.
https://www1.grc.nasa.gov/wp-content/up … _FINAL.pdf
This has enormous implications for the future use of nuclear power in space travel and on Earth itself. It means that nuclear reactors can be built using abundant non-enriched uranium and can achieve high burnup without reprocessing.
For a nuclear thermal rocket or Mars surface nuclear reactor, it allows the launch of non-radioactive payloads. Additionally, a Mars surface reactor can use native Martian uranium as fuel without need for enrichment. It will achieve high burnup and will not depend upon reprocessing.
Without need for HALEU or HEU, nuclear thermal rockets will be much easier to deploy. We could also build fission fragment engines with exhaust velocity as high as 4%C. That puts the nearest stars in reach of slow interstellar probes. At 4%C, Proxima Centauri is only a century away. The exciting thing is that this is something that could be done relatively soon.
The video below details some of the nightmare distopian laws coming to the UK in 2025.
https://youtu.be/sc-PB_pWggk
The Dems tried to impose this sort of state tyranny on the US, but were held back by the constitution and supreme court. The same thing succeeded in the UK, because it doesn't have a written constitution that defines the relationship between state and individual. If a government is elected with a majority, it really is free to impose anything it wants. The Crown, which is supposed to function as the ultimate backstop against a dangerous parliament, rubber stamps all laws produced by parliament without question.
The UK government is openly evil. It clearly does not value human freedom. It views personal initiative as a threat to its authority. Poll after poll indicates that this is the least popular government since records began. But Starmer has taken the position that he no longer cares about public opinion. We are stuck with him and his lackeys for another 4 years and he will do what he wants to do in that time. The king is the ultimate arbiter of government authority. A good king would dissolve parliament at this point and force a general election. But our king is weak and sick.
The UK has become a place where anyone wanting a decent future and any measure of self determination, has to leave. It is that simple. And that is exactly what I intend to do. It is what I recommend everyone to do.
Land area of Mars compared to countries on Earth.
https://youtu.be/zBuO99DkCPU
This helps visualise the size of the place. Exploring its surface will take a lot of time.
The trade policies of the second Trump administration may be a window of opportunity for a new beginning.
https://youtu.be/zB2MEgzmA0M
There are obvious problems with the CANZUK alliance, not least of which is the need to find a catchier name for it. Logistics is the key problem. The members would be seperated by vast oceans. That is a natural barrier to trade. One issue that the video raises is that CANZUK already exists in most important respects. Canada, UK and Australia already cooperate on military projects. There is already trade between them and cultural affiliation.
Perhaps the biggest barrier is leftwing politics. All four countries are run by entrenched leftwing, globalist parties. CANZUK would largely be based on ethnic kinship. Something that leftwing parties have always done their best to marginalise. The recent elections in Canada and Australia, both returned leftwing governments as part of a temper tantrum against Trumpian politics. Ironically, this will make it more difficult for both countries to do anything proactive to improve their situations.
Introducing 2017OF201, the solar system's most recently discovered dwarf planet candidate.
https://en.m.wikipedia.org/wiki/2017_OF201
This object has a highly eccentric orbit. Its perihelion is 44AU. Its aphelion is an enormous 1600AU. It may in fact be a scattered body from the inner Oort cloud.
Whilst these objects may not at first appear to be promissing places to live, they have the advantage of being heat sinks. One of the limitations on free space habitats, us the need to dump waste heat into space, which can only be done by radiation. This limits the size and density of habitats, as radiator area ends up dominating the size of the structure. With a heat sink, these limitations are removed.
Imagine building an O'Neil cylinder 20km wide and 50km long. The internal surface area would be about 3000km2, about the size of a county. Now imagine decking the inside, with 10m between decks. Internal land area is then 1.5million km2. That is about half the size of the continental US. Such internal subdivision would be impractical in free space, because the waste heat generated by the lighting of this much land would require a radiator hundreds of thousands of square km in area. But if we build our hab on an icy body, we can pump water through it and use the volume of the body as a place to dump heat. Such a large and cold body would take many tens of thousands of years to melt.
Britain is a depressing place to be right now. An oppressive police state that is in a constant state of war against its own people. Some 30 people arrested each day for comments on social media. People jailed for failing to give their mobile phone pin numbers to police. Kier Starmer doesn't seem to care about public opinion or the good of the people. He seems to be on a mission to do as much damage as he can before he is booted from power. A genuinely grotesque and vile individual. I am shocked that there are still people that think he is a nice guy. Then again, Winston Churchil thought Stalin was a good guy.
I hope Reform can achieve power and undo the damage inflicted on Britain by its miserable succession of post-war Labour and Tory governments. The public have finally awakened and are angry. Nigel Farage is clearly a narcisistic individual. I hope Reform surprises on the up side and doesn't collapse under the weight of a selfish leader in the way the old BNP did. Britain clearly needs a renaissance.
I am not sure what you mean by Albion. This was an ancient name for the island of Britain.
I have been working on my wind powered tumbling machine over the past two weeks. I realised some time back that I needed to mount the nacelle and its cradle atop a tower in order to access stronger wind and avoid ground turbulence. However, mounting the device on a tower introduces new difficulties. Stability is one of them. The device needs a wide base to prevent toppling. Bending moment at the tower base is another problem. I have added reinforcing struts to the device and will also be adding bracing cables. I will include photos of the finished device when it is finally assembled. It should be ready in another week.
For Void re post with images and GIF of asteroid NEAR probe...
https://newmars.com/forums/viewtopic.ph … 94#p231794
That is an impressive composition!
Your recent introduction of the idea of using iron as propellant (reaction mass) might inspire one or two readers to wonder about the potential impact such highly accelerated iron atoms might have when they encounter the hull of a space craft. Your post includes mention of building up layers of material for radiation protection, and provision for arrival of the iron atoms used as reaction mass might seem advisable.
(th)
Short answer: none. Heavy ions have a very short range in matter (microns), due to their interaction with electron shells. Look up the Bethe-Bloch equation. Also, ions will tend to be swept away by solar wind.
One area where this could potentially be a problem, is planetary magnetospheres. Whilst interplanetary space is vast, the Earth's radiation belts start about 1000km above its surface. If they are pumped with ions that are accelerated as Earth's magnetic field lines sweep them, it could do damage to exposed components like solar panels.
There are problems with this idea.
Firstly, it could trigger a new nuclear arms race. If aggressor nations know that the US has a defence system that can shoot down 90% of incoming missiles, will they respond by increasing their total warhead count 10x? This would reverse arms reduction treaties.
Secondly, it is relatively easy to destroy a satellite, simply by putting another satellite on a collision course. That satellite could be a cubesat, or even a ball bearing released by another satellite. If a conflict starts in space, it wouldn't take many such events to result in Kessler syndrome. If that happens, all space infrastructure becomes useless. We would have to wait until atmospheric drag clears out low orbital space before launching anything again. That could take decades.
Whilst space is vast, Low Earth Orbit is a strategic choke point that all nations must cross to get anywhere else. If it gets fowled up with debris, then everyones space ambitions are over for decades at least.
For Calliban re post in Astronomy...
https://newmars.com/forums/viewtopic.ph … 89#p231789
Thanks for that ** interesting ** addition to the topic!
As a preliminary assessment ... I wonder if a rogue planet created in this way might be limited in atom types.
Planets (that I know of) seem to contain atoms that were produced by exploding stars.
But (thinking a bit more ...) ** those ** planets would have been created from collections of material just drifting in open space before gravity pulled them together.
(th)
I am uncertain. I think it would depend heavily on the composition of the nebula that forms the star systems. As the universe grows older, metallicity is slowly increasing. This seems to favour the formation of large planets (larger than Jupiter) over smaller ones like Earth and Mars. Collisions between discs are more likely to involve the outermost regions of protoplanetary discs, which tend to be preferentially enriched in lighter elements. I suspect that the composition of these JUMBO planets will vary.
One thing that we do know from study of lunar lava tubes, is that on worlds with weaker gravity, caves can remain stable with diameters much greater than on Earth. In fact, maximum possible diameter appears to be ~1\g^2. On Vesta, with about 5% Earth gravity, it should be possible for caves to exist that are 400x larger than on Earth. When we begin mining such bodies, it should be possible to dig out caves many kilometres in diameter. The crusts of the large asteroids could be hollowed out like swiss cheese and the vacant spaces filled with breathable air and ecosystems.
I wasn't quite sure where to put this and I think it needs its own thread.
https://en.m.wikipedia.org/wiki/Gravitational_biology
Life that adapts to a weaker gravitational field could end up being very different to life on Earth. The maximum possible size of individual cells is inversely proportional to gravitational field strength. So larger cells are possible in weaker gravity.
This suggests that if life is found on Mars or on smaller outer solar system bodies, it may have developed very differently. The potential for larger cells opens the possibility of evolutionary pathways that were never possible on Earth.
If we ultimately terraform smaller bodies using shell world methods, evolution in these new ecosystems could also take unexpected turns.
It turns out that many rogue planets are created by colliding protoplanetary discs in dense star clusters.
https://www.space.com/the-universe/thes … or-planets
Bodies created in the way would be relatively uncommon, because protostars would need to come within about 1000AU of each other.
By my estimates, the mass ratio of a LOX/RP-1 SSTO would be about 15. Which means that the entire vehicle and payload would need to be no more than 6.7% of takeoff mass. That is a very thin structural margin, especially if it includes thermal reentry shielding. Some kind of launch assist would appear to me to be a necessity for this concept to have a chance of working. If we can shave 30% off of the fuel required to reach orbit, then a reusable LOX/RP-1 SSTO can get to orbit with a more achievable mass ratio of about 11. That is still tough to do. But it is possible.
Another option would be a two staged vehicle, with both stages being reusable. This is exactly what SpaceX are doing.
Interesting review of the human reach book series.
https://youtu.be/h5SiNBnX0AE
Takeoff and landing sites will need to be a long way from any inhabited structure. It is probably a good thing that practically all of the structures will be underground.
Liquid ammonia has a higher hydrogen density than liquid hydrogen and can be stored at about 6bar vapour pressure at room temperature. The obvious disadvantage is that ammonia has molecular weight of 17amu. To transport 3kg of hydrogen, we need to send 17kg of ammonia to Mars. Still, it might be a positive tradeoff. Another advantage is that ammonia (or methane) shipped to Mars can be used as rocket fuel without further synthesis.
Calliban,
What you're describing sounds a lot like the M2P2 (Mini-Magnetospheric Plasma Propulsion) system proposed by Dr Winglee et al, IIRC. His group did a bit of work on refining it and developing some hardware for that concept, but it was only ever tested in a lab, so far as I know.
Very similar, except that M2P2 was a static, inflated magnetic field. It can only accelerate in the direction of the ions, which is away from the sun. A spinning magnetic field would impart momentum into the ions, by sweeping them with rotating field lines. So thrust could be directed.
To be honest, I have no idea how well this would work. Thrust would depend upon ion density. This is high when close to the sun and during solar activity. But out in the interstellar black, it is much lower. Still, this is a propulsion system that doesn't require that the ship carries reaction mass. So it has that going for it. As the ship accelerates w.r.t the ion current, it will begin to experience increasing drag and effective exhaust velocity will decline as flux increases. So there would be a realistic top speed for this type of propulsion.
Until about 2007, the majority of PV was still being made in developed countries. After that, Chinese PV production increased enormously and now completely dominates the global market. Chinese PV is very cheap, because it is made using otherwise stranded coal and forced labour. Anything is cheap when the labour and energy used to produce it are almost free. Anyone that wants to buy Chinese PV should do it soon. At the rate the Chinese economy is unwinding, it isn't clear how long they can keep PV module production going at the scale it is now being produced. PV module production depends on very long supply lines. The majority of polysilicon is made in Xinjiang and Inner Mongolia. Place with large and unexploited coal reserves and cheap labour.
Using PV to produce direct DC power without backup, is the only way of producing electric power from PV that is affordable and has positive EROI. Adding batteries and inverters massively increases cost and embodied energy. Adding backup power also destroys economics because the consumer must pay for a whole extra power station that sits idle for much of the time.
But using direct solar (daylight power) only really works in a small microgrid. For one thing, DC in the 180 volt range, cannot be transmitted long distances. Another problem is that load must be adjusted to match supply. That cannot easily be done in an extensive grid where customers are cut off without warning. But it can be done locally. If a household owns its own solar or wind DC power supply, the people living there can adjust load to match supply. It works much better if there is a discretionary load that can be rapidly switched off. Like resistance heaters in a hot water tank.
The Chinese economy is crumbling.
https://youtu.be/-qRNJMttBhE
The impact of the tariffs is still to come. Deflation is primarily the result of insufficient demand in the Chinese home market. This is a direct result of the demographic crisis which is now irreversible on a timescale shorter than several decades. The Chinese made the mistake of combining the one child policy with rapid urbanisation, which was associated with rapid growth in the manufacturing economy. The result is a generation of Chinese without kids. Not having kids gives a short term boost to an economy. Without children, adults can work long hours. The money they make can be reinvested, resulting in high economic growth. But there is a terrible price to pay. Without children, there is no long term future. Back in the 1990s, the time of reckoning must have seemed a long way away. But however distant the future may appear, it eventually turns up.
One option for a 'propellantless' propulsion system would be to equip a ship with rotating magnetic fields. These would tend to drag solar or interstellar ions along the field lines around the ship. As the field is imparting momentum into the particles, it will develop thrust, probably very small. But speed can build up over many years. Tthis isn't strictly propellantless. It is a bit like a propeller, that uses diffuse plasma as reaction mass instead of water.
Quantum theory tells us that virtual particles are continuously created in the vacuum and disappear almost instantly. If a rotating magnetic field can impart momentum into charged virtual particles, it will generate thrust. This would be a truly propellantless drive.
Nate Hagens interviews Alexis Zeigler, founder of Living Energy Farm.
https://youtu.be/vTIaxj8gRRc
This is a community of likeminded people who live on solar energy. Zeigler's approach is particularly interesting. Small amounts of electricity are stored in batteries for things like lighting. But most appliances run on DC power directly from the panels. There is no inverter or battery inbetween. Kris DeDecker has similarly written about direct solar power and estimates that only 10% of a typical offgrid system lifetime cost is the panels themselves. The inverter and batteries are 90% of total cost.
Living on direct solar means adjusting load to match supply at any particular time. This clearly isn't ideal, because sunlight levels vary across the day, between days and throughout the year. So using solar power in this way requires some rather deep behavioural adaptations. The use of low voltage DC does help. If too much load is switched on for the power supply, motors run more slowly and lights start to flicker. So there are obvious signs that allow consumption to be balanced to supply. Some energy activities can be postponed until sufficient energy is available.
Living like this isn't easy. But if we can learn to collectively adapt to intermittent supply, then an energy transition to intermittent renewables in possible. If not, we all need to bite the bullet and start building new nuclear reactors in a serious way.
Sabine Hossenfelder discusses rain panels.
https://youtu.be/mYm49Kd4Gy8