- Parabolic Arc
- June 1, 2023
Planetary LEGO Blocks Take Shape in Hawaii
HILO, Hawaii (PISCES PR) — These LEGO blocks are not the familiar plastics bricks you may have pieced together as a kid or given to your children to play with. In fact, these blocks could one day form the foundations of habitats and infrastructure supporting astronauts on places like Mars, the Moon and other worlds.
Funded by a NASA Phase 1 STTR grant last year awarded in partnership with Honeybee Robotics, PISCES set out to research innovative designs for building blocks made from locally sourced volcanic basalt. The objective was to create a prototype planetary LEGO brick using local, raw materials that could be made robotically on other planets. The process, known as ISRU or in-situ resource utilization, could also be used to create sustainable building materials on Earth. Now, nearly one year since the project began, the goal is nearly in sight.
After spending many long days in the lab experimenting with various thermal profiles and mold designs, PISCES Geology Technician Kyla Defore and Operations Manager Christian Andersen have finally created the full-size block design they intended. But this not-small achievement came with a few challenges.
Using only rock dust from Hawaii Island quarries and sustained heat, many of their early attempts were fraught with stress cracks and other imperfections, which compromised the structural integrity of the full-sized bricks. The problem seemed to lie in the initial mold designs, which were expanding during heating periods and contracting when cooling.
After adding insulation materials to prevent varying temperature gradients (or temperature changes at different places along the brick) and adjusting the mold design to secure the basalt, they found a winning technique that created a usable Planetary LEGO block free from defects.
The final step in the project will be stressful—for the LEGOS. To determine how they measure up to conventional building materials and how they might withstand harsh environments, the LEGOs will undergo flexural and compressive strength tests. If previous efforts are any indication, the blocks will likely perform well.
During a robotic launch and landing pad project conducted in 2016, PISCES sintered a series of basalt pavers tiles that exceeded the strength of residential and specialty concrete. Planetary LEGO blocks are the latest incarnation of this research, and the next step in their evolution will involve the production of more samples to begin building various structures that can be tested and shared with the ISRU community.
20 responses to “Planetary LEGO Blocks Take Shape in Hawaii”
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So like Boring Bricks but using heat as the binder instead of a very small amount of cement, the binder you use in various environments depends on the situation, on Mars, because of carbon and water, and making epoxy may be viable, but the regolith is a low grade iron ore so heat shouldn’t be hard to make work, it will be a question of energy, demand and available resources.
Maybe a solar reflector farm with a solar oven, or nuclear powered oven for cintering blocks?
Solar oven or a battery/alternate energy storage to a laser, or even just burning stuff, nukes are not an ideal option, anywhere you would want to live long term will almost certainly have enough solar power income that you don’t have any real cost advantage, it will likely cost much more
The “ideal” energy solution is one that has no mass, occupies no volume, requires no inputs, is cost-free, requires no maintenance, is 100% reliable and produces energy at any required level indefinitely. In short, there is no “ideal” energy source for either terrestrial or extra-terrestrial applications.
So there’s no obvious reason to disparage nukes or put them off-limits. I’m inclined to agree that uranium-based reactor cycles – especially those that require enriched uranium as fuel – have significant drawbacks for extra-terrestrial use. Their biggest drawback is the difficulty faced in reproducing their huge industrial/logistical “tail” from scratch off-world. Their second biggest drawback is that uranium seems even harder to find in quantity off-Earth than on. Their third biggest drawback is the waste reprocessing/disposal problem though this is, in the long run, a very minor difficulty compared to the first two.
The obvious answer is to use Thorium which requires no enrichment, is far more available in extraterrestrial places and which creates a much less problematic waste stream.
To the extent that colonization of planetary surfaces ever gets to be much of a thing, Thorium reactors appear preferable to a solar-plus-storage surface-based alternative. For in-space habs of all sizes, though, solar power is the obvious way to go – either directly acquired on-site or concentrated and beamed for sites beyond Mars orbit. Solar power from orbiting platforms beamed to the surface is probably also the preferred baseload solution – long-term – for anyplace on any natural body’s surface out to, and including, Mars.
Stirling engines do not care where the heat comes from so the electrical generation part of the system can form a tested component of the Thorium reactor.
Thorium reactors have a very low energy density, their size makes it so you’d have to build most of it on site, while certainly doable, you need to already be started and have some infrastructure before you can do such a task, and to get to that point, Solar is likely your best bet
remember for surface based power though you have plenty of additional power sources in organic cycles, and there’s waste heat being put through Stirling engines to increase efficiency, other power sources exist, but are dependent largely on envirorment and avaliable manufacturing capability, wind is possible (though difficult) on Mars but you would likely need to be producing carbon fiber to get a turbine with a high enough surface area to mass ratio to be meaningful. On Titan you might need nukes unless you can get oxygen easily, alternatively you could take advantage of the fact that its passing through Jupiter’s magnetic field and presumably a vertical conductive rod will be able to tap into that power effectively, all depends on the situation.
It’s interesting that you mention Titan, Michael. Arthur C. Clarke, in his novel “Imperial Earth” postulated that Titan was colonised to take advantage of the abundant simple Hydrogen compounds contained within Titan’s thick atmosphere and sub-surface water, Methane powered the Solar System’s Hydrogen based economy. IMO, the only part of the novel that really dates it, is the bit about the Titanic. But it is still an interesting read and quite insightful given the time that it was written (the nineteen fifties). So Hydrogen/Oxygen fuel cells would probably be the “go to” source of reliable electrical energy for settlements upon Titan. Regards, Paul.
You still need the oxygen,
And fool cells aren’t a source they are storage, besides with all the hydrocarbons there like methane lakes, you don’t need to settle for hydrogen
There is no such thing as a “Thorium Reactor” as such – Thorium is bred to Uranium233, which is the actual fission fuel. This would usually require 20+% enriched uranium, or plutonium as startup fuels. Also, a Thorium232 to Uranium233 breeder requires expensive Lithium/Berilium salts and the added expense and complexity of continuous online chemical processing.
With that said, Thorium breeders hold a lot of promise for the centuries ahead (Earth, Moon and Mars have over a billion years worth of Thorium deposits), but a LEU (1-5%) uranium burner, is a much simpler and less expensive reactor system. The cost of the fuel for a uranium burner would be about 0.1 cents per kWh and the mass of uranium for transport to a Martian (or lunar) colony would be insignificant compared to energy return – it’s the capital cost and effort of the power plant that is the problem. The equation for off-Earth is mass and cost of solar panels + batteries vs mass and cost of nuclear power plant.
The other cost of the uranium burner is the increased reliance on Earth sourced consumable resource, if you are setting up a colony, especially early on, profit isn’t guaranteed or going to be immediate, so there will be difficulty in justifying the cost of the uranium potentially putting it out of reach until the colony starts being productive, tieing yourself to it for power brings up all sorts of chicken and the egg problems. You need to bootstrap the colony first and nukes do not lend themselves to that.
“…difficulty in justifying the cost of the uranium…”
You’re missing the point – the uranium fuel is the cheap part – it’s the construction of a power plant that’s expensive – although not as expensive as panels and batteries.
“You need to bootstrap the colony first and nukes do not lend themselves to that.”
Yes, you do need a significant amount of infrastructure to be able to construct nuclear power plants. Whereas panels and batteries for the first dozen or hundred or thousand colonists can be done straight away. Mind you, the BFS fuel factory will require 2 MW a day (for 2 years) to fill one BFS for return.
Yes and there are secondary power sources, waste heat from industrial/manufacturing processes, and so on, for power sources you make on mars, there’s also concentrator solar thermal, or even using mirrors to enhance the output of the solar panels you have, for storage, there’s a lot of options other than battery, lots of energy loss, but more accessible, your fuel production is energy storage, there’s pnuematic and waste to energy (sewage and compost gas), agricultural byproduct fuel, and so on, you don’t need to jump into the most high preforming technology that matches what you have available on/from Earth, you just need stuff that works.
I wasn’t just talking about the transportation of the fuel but the fuel itself and the political related costs
If you are going to use solar energy to make rocket fuel you will also be able to use a variation of that fuel to run generators solving the night cycle energy problem. And if you are real clever you will capture, compress and store the exhaust for reprocessing by solar electric energy when the Sun returns.
A reactor will work well for the settlement, but solar would be fine for making the blocks since it doesn’t have to be a continuous process but could just be working when the Sun is available.
Nuclear waste disposal would not be a problem on the Moon, just dump it outside the work area, shovel up a wall of regolith around it and leave for a future generation to reprocess into useful products when the technology emerges. Unlike Earth disposal, any society that is able to exist eons in the future on the Moon will need to have a knowledge of radiation and nuclear energy by default.
Totally disagree, Michael. Where ever we “modern” humans go, we require, amongst other things, a reliable source of power. Electricity generation relying upon energy captured from the Sun, especially upon planetary surfaces that experience weather, have significant problems with reliability. This energy also relies upon excess generation capacity having to be stored for later use (usually by the use of batteries). As they are scaled up, these systems become more and more complex and more and more expensive to maintain. IMO, this is the main reason why NASA is going to the effort and considerable expense to have space based nuclear fission reactors developed. Also, IMO, they will be absolutely necessary, like instantaneous communication employing nodes that use the phenomenon of quantum entanglement, to the turning of the human race into a viable multi-planetary species. Regards, Paul.
Where other than Earth will your weapons grade uranium come from? Nukes are a logistical nightmare beyond RTGs, RTGs are merely a headache
Thanks for your reply, Michael. I didn’t mention the fission fuel type. Dick, here, has mentioned Thorium as a possible/preferable fission fuel source. What I only care about is that nuclear fission, as a power source, is reliable. A close analogy is the research stations at the poles. They have back-up generators, because if for any reason they cannot generate power for any significant period of time, especially during winter, they would eventually all freeze solid. So the three most important factors to do with power generation and permanent off-Earth settlement will be reliability, reliability and reliability. 🙂 Regards, Paul.
solar is reliable too, Opportunity has been running on it for years, its not constant, no but its predictable, problem with thorium is the reactors are huge, not a problem if you already have the ability to build stuff but you need energy to be able to build stuff in the first place, which is why in almost all situations your initial energy source is probably solar, and there are a lot of secondary power opportunities, in waste management and waste heat, taking advantage of those reduces the need for nukes significantly, if you are cleaver, you can actually get a lot of power from just solar as primary, you dont lose heat as easily with significantly less outside atmosphere, it is even possible getting rid of it over time may become an issue, and if you are producing methalox to power a rocket to send back to Earth, no reason you cant use that for extra power to hold you over if needed, by the time you can make a reactor, chances are you will already have the reliable power problem solved, and its just extra power