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For Calliban re radiator ...
At 700°C, that radiator would need to be 2.5 x 2.5m, ignoring conduction losses into the vehicle.
Please add detail ... we only (appear to) have 2 dimensions given in the specification.
I'm assuming there are pipes into which the sodium flows, separated by sections of flat metal.
Detail: between episodes, the sodium will solidify in the radiator pipes. It this intended to be a one-time-usage emergency backup?
If so, would maintenance / remanufacturing consist of melting the entire device down and separating the elements for re-use?
I like the automatic safety feature for the base station. It would (of course) not be available to the mobile units.
(th)
We need a design that assures that fuel cladding remains intact following any reasonably foreseeable malfunction. Otherwise, a malfunction could leave us with a toxic mess to clear up. This could be provided by liquid sodium flowing through a radiator driven by natural circulation. If the cooling circuit opens by melting plugs, then you have a passive activation that would occur without any operator action. It would be irreversible and would write off the asset, but would maintain the core intact.
No operator being present for refilling is a bit of a problem. Maybe propellant line insertion could be automated?
"Plan and prepare for every possibility, and you will never act. It is nobler to have courage as we stumble into half the things we fear than to analyse every possible obstacle and begin nothing. Great things are achieved by embracing great dangers."
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For Calliban re #301
Thanks for expanding a bit on your basic ideas!
The automation of a delivery hose is well under way on Earth. Commercial offerings are definitely in discussion.
For SpaceNut ... please keep a watch for announcements along those lines. Science Fiction has had them for decades, and I'm not sure what I am thinking about is from science fiction or advertising of actual products.
I ** think ** Tesla has plans for automated plug capability, and a few beta sites may exist. i'm just not sure.
In any case, it is definitely needed for the Mars mining operation.
The same is true for GW Johnson's on-orbit refueling system.
GW, like you, started from an assumption there would be people on the scene, because that it how it has always been done, but we are now in the age of remote manipulation, and have been for several decades in satellite designs.
(th)
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I sort of described its use as well as the turbine for the equipment for the 1 meter regolith water gathering as calliban had suggested that the air intake might make use of a turbine to get a greater level of co2 gathered.
Lets we forget the earth engines are of all different cylinder sizes so sizing of a mars engine will work the same in the design of power to make use of in the variety of uses that we will have,
The cylinder is 1 bar of air an the ration of that air is related to 14.7 psi so we are using 14.7 parts to 1 part fuel in the cylinder. So while we are making use of high pressure tanks for the mars gasses we are only still looking to send in a near 1 bar solution for creating rotation power whether its by a turbine of a piston makes little difference in the end.
As far as radiators we have the KRUSTY design which will work, I gave a refrigerators style but we can also use a flat plate solar collector as the electronic heat-sink design as well.
The flat plate we would alter as we do not need the glass and we can use thinner metal with holes in it to make the plate radiate the heat that enters through the tubing.
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MIT design for Mars propellant production trucks wins NASA competition
https://www.marsdaily.com/reports/MIT_d … n_999.html
Using the latest technologies currently available, it takes over 25,000 tons of rocket hardware and propellant to land 50 tons of anything on the planet Mars. So, for NASA's first crewed mission to Mars, it will be critical to learn how to harvest the red planet's local resources in order to "live off the land" sustainably.
On June 24, NASA announced that an MIT team received first place in the annual Revolutionary Aerospace Systems Concepts - Academic Linkage (RASC-AL) competition for their in-situ resource utilization (ISRU) design that produces propellant on Mars from local resources instead of bringing it from Earth.
Their project "Bipropellant All-in-one In-situ Resource Utilization Truck and Mobile Autonomous Reactor Generating Electricity" (BART and MARGE) describes a system where pairs of BART and MARGE travel around Mars in tandem; BART handles all aspects of production, storage, and distribution of propellant, while MARGE provides power for the operation. After presenting their concept to a panel of NASA experts and aerospace industry leaders at the RASC-AL Forum in June, the team took first place overall at the competition and was also recognized as "Best in Theme."
"Previous ISRU concepts utilized several different small rovers and a fixed central plant, but MIT's BART and MARGE concept is composed of essentially just two types of fully mobile, integrated large trucks with no central plant," says Chloe Gentgen, PhD candidate in the Department of Aeronautics and Astronautics (AeroAstro) who served as team lead for the project. "The absence of a central plant enables easy scalability of the architecture, and being fully mobile and integrated, our system has the flexibility to produce propellant wherever the best ice reserves can be found and then deliver it wherever it is needed."
Gentgen led an interdisciplinary group of undergraduate and graduate students from MIT, including Guillem Casadesus Vila, a visiting undergraduate student in AeroAstro from the Centre de Formacio Interdisciplinaria Superior at the Universitat Politecnica de Catalunya; Madelyn Hoying, a PhD candidate in the Medical Engineering and Medical Physics program within the Harvard-MIT Program in Health Sciences and Technology; AeroAstro alum Jayaprakash Kambhampaty '22, rising MIT senior Mindy Long of the Department of Electrical Engineering and Computer Science (EECS); rising sophomore Laasya Nagareddy of the Department of Mathematics; rising junior John Posada of AeroAstro; and rising sophomore Marina Ten Have of EECS.
The team was formed last September when interested students joined the project. AeroAstro PhD candidate George Lordos, who founded the MIT Space Resources Workshop and who has led or advised all MIT NASA competition teams since 2017, was a mentor for the project team. Jeffrey Hoffman, professor of the practice in AeroAstro; and Olivier de Weck, Apollo Program Professor and professor of astronautics and engineering systems in AeroAstro, served as faculty advisors.
"One year ago, the MOXIE experiment led by Dr. Michael Hecht and our team's advisor, Professor Jeffrey Hoffman, produced the first oxygen on Mars. Today, we are on the cusp of orbital test flights that will bring us closer to the first human mission to Mars," says Lordos.
"As humans venture to other worlds, finding and utilizing local water and carbon resources will be indispensable for sustainable exploration of the solar system, so the objective of our MIT team's concept is an exciting and topical technology."
The MIT team addressed the RASC-AL theme "Mars Water-based ISRU Architecture," which required delivering the target 50 tons of propellant at the end of each year and the ability to operate for at least five years without human maintenance. A few other constraints were placed, chief among them that teams could rely on one or more landings of 45 tons of mass and 300 cubic meters of volume on Mars, leaving it to university teams to propose an architecture, budget, and a flight schedule to support their mission.
They developed a comprehensive Mars mission architecture and defined a comprehensive concept of operations, from a precursor ice scouting and technology demonstration mission in 2031 to the main propellant production, storage, and delivery mission in 2036. BART is an end-to-end "ice-to-propellant" system that gathers water from Martian subsurface ice and extracts carbon dioxide from the red planet's atmosphere to synthesize liquid methane and liquid oxygen bipropellant. These are then stored onboard at cryogenic temperatures until delivery directly into a rocket's propellant tanks.
BART is accompanied by MARGE, a 40 kilowatt electric mobile nuclear reactor based on NASA's Kilopower Reactor Using Stirling Technology project (KRUSTY, which also inspired the MIT team's name) that generates power from nuclear fission to support long-duration operations on distant planets.
For the team's proposed mission, four tandems of BART and MARGEs will roam the region known as Arcadia Planitia at the mid-northern latitudes of Mars following a prospecting rover named LISA (Locating Ice Scouting Assistant) in search of accessible ice to use for propellant production. The entire system has 100 tons of storage capacity and can produce 156 tons per year, against a demand of 50 tons per year, and requires only three landings.
Another discussion on fuel
and building large smelting production
Combustion engines ... - ... on Titan and Mars
https://newmars.com/forums/viewtopic.php?id=3515
Last edited by Mars_B4_Moon (2022-07-12 06:42:02)
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thanks for the post on the use of a 40kwe version of a mobile reactor and drilling water to fuel units as this needs to go in a few more topics.
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This was intended for post 10 of the topic update edit but here it is in a new post or in this case a repeat.
This post includes a link to a video about torquing the head gaskets in a Suburu.
It was posted by SpaceNut in Housekeeping...
SpaceNut wrote:Just now got error with cellphone edit post for a link on Subaru head gasket video
https://youtu.be/o7p_fWXqoSE(th)
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The question keeps bugging me as I know that we use energy in a non-average mode all the time and that due to the grid and how others are using their own we end up with a more stable with peak loading on the grid.
How Many kWh Per Day Is Normal? Average 1-6 Person Home kWh Usage
Here is the total US residential electricity consumption of 118.2 million US homes:
All in all, we use 1,267 billion kWh of electricity per year. The total cost of this electricity is $219.34 billion annually.
We spend 214.2 billion kWh (16.9%) on air conditioning.
We spend 186.9 billion kWh (14.8%) on space heating (usually on heat pumps).average home will use 10,720 kWh of electricity per year. That comes to 893.33 kWh per month, 205.59 kWh per week and, finally, 29.37 kWh per day
I just got my electrical bill and my daily use for the last month was double the above with just an electric heater to keep the home at 55 to 60 F. Normally its down near that amount when warm as we do not use AC just fans.
This accounts for no energy for a vehicle or other concerns in which we might want some for use.
Of course, a solar thermal and storage would change that but still not all would be solved.
From a solar panel energy provider How Many KWh Does A House Use Per Day: Ultimate Guide
Numbers that raise a question for what is average... Meaning that the real energy is most likely higher.Other things to consider are not all homes are of equal insulative quality and not all homes see the same cold or heat of the seasons.
Also, since cars would need to be all electrical to get a real total and all I have is the hybrid and gasoline to make use of then let's see if we convert to a gas source for the electrical how that will look.
Conversion: Kilowatt Hour to Gasoline Gallon Equivalent with numbers that if I feed that little amount of gas into a generator would fail to produce the electrical one would get.
1 kWh = 0.029678483099753 gge
Most references on how much gasoline a generator uses report averages of three-quarters a gallon per hour at normal load.
So if we look for a generator that produces 2kw then we have the bare minimum looks like 4 hrs on a gallon. Which is a far cry from a 24 hr clock and then you need several of them to allow for cool down cycles so as to not destroy them.24 hr x 1.5 kw = 36kwhr daily required at $4 a gallon x 6 for the day = $24 a day... 30 day average = $720 a month ouch as that is really high an add to that the vehicle which is $60 a week brings the fuel cost to $960 for everything.
Sure, other fuel types will be just different numbers, but they are still too high...
So how much oxidizers do we need and what is it energy cot.
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For SpaceNut re #307
Thanks for the reminder that our readers need to see the results of previous work in this topic, from time to time. Otherwise, it is natural for memories to fade, to the point that even something as basic as the amount of oxidizer needed is up for question.
To remind everyone (as is thoroughly documented in this topic, which has reached over 300 posts) ...
Carbon dioxide is abundant on Mars
The most efficient possible way to store energy and use it when needed on Mars is to separate CO2 into CO and O2
There are numerous ways to consume CO and O2 in a variety of machines.
Recently a member of the forum discovered that work has been done to create a fuel cell that generates electricity directly by consuming CO and O2.
From my perspective, this last approach has many advantages over mechanical systems, such as the ones for which this topic is named.
Never-the-less, an Internal Combustion engine will work just fine on Mars, and we recently even confirmed the size of the storage tanks for CO and O2 that must be mounted on vehicles that venture out onto the Mars landscape using this energy supply.
If you have time and would be willing to take this on, please research the topic and find the references where this solution is worked out.
(th)
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For SpaceNut re topic ...
A nice addition to the topic, if you have time and the effort seems worth while, would be to work out a table of tank sizes for machines that would be used on Mars to travel, or to do work.
We've established the size of the storage tanks, and that information is posted in the forum, but I have already forgotten which molecule is twice the volume of the other. In any case, regardless of which molecule requires twice the volume of the other, the vehicle MUST have onboard storage for CO and O2 as gases. Making liquids is energy expensive and totally unnecessary for any but the most extreme of expeditions.
I'm hoping someone in the forum membership will be willing to create a table of tank sizes that includes energy storage and approximate vehicle range, or machine tool operating life, depending upon the application.
(th)
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Here is some more of what makes todays car the way that they are.
Where the Energy Goes: Gasoline Vehicles
A car using gasoline will create from 1 gallon or 6.3 lbs of fuel, 20 lbs of co2 from an approximate 14.7 ration to 1 of which if we had to carry the mass of atmosphere to burn the fuel makes for 23.22 lbs of oxygen is required. To which the total 100 lbs of air is just for that 1 gallon. Now fill the tank up for range and you now have something that will be why conversion to other source of energy is a challenge.
Then again a new heat engine design is in process of determining values
Here
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