At 300 watts to get about 6 g to 12 g which a far cry for an hour runtime when we need roughly 600 g for a days' worth of breathing per crewman.
Thanks to Void we have another to make use of in "Mars Direct 3 is a Mars mission architecture developed by Miguel Gurrea" topic.
https://www.marspapers.org/paper/Gurrea_2021.pdf
Plus Mars direct was a 40mT payload
https://www.marspapers.org/paper/Zubrin_1991.pdf
A reuseable craft requires the means to make the fuel of choice.
]]>Elon Musk Criticizes Stagnant Space Exploration, Stating: 'Humanity Should Have A Moon Base, Cities On Mars And Be Out There Among The Stars'
https://finance.yahoo.com/news/elon-mus … 38307.html
some backup ideas because you can never have too much air?
Chemistry? ISS Oxygten Candle and SCOGs are used in submarines, on Commercial aircraft provide emergency oxygen to passengers.
2 NaClO3 → 2 NaCl + 3 O2
LiClO4 → LiCl + 2 O2
discussion Chemistry - Chemists - Chemicals
https://newmars.com/forums/viewtopic.php?id=10415
Trees, Plants, Algae, Photosynthesis like aquatic plants, algae also produce oxygen via photosynthesis.
Current experiments on algea, lichen etc.?
https://newmars.com/forums/viewtopic.php?id=236
Productive walking Baba Yaga Robot Trees.
https://newmars.com/forums/viewtopic.php?id=9563
Mass About 37.7 pounds (17.1 kilograms) on Earth
https://mars.nasa.gov/mars2020/spacecra … nts/moxie/
Weight 37.7 pounds on Earth, 14.14 pounds on Mars
Power 300 watts
https://www.spacedaily.com/reports/NASA … E_999.html
Since Perseverance landed on Mars in 2021, MOXIE has generated a total of 122 grams of oxygen - about what a small dog breathes in 10 hours. At its most efficient, MOXIE was able to produce 12 grams of oxygen an hour - twice as much as NASA's original goals for the instrument - at 98% purity or better. On its 16th run, on Aug. 7, the instrument made 9.8 grams of oxygen. MOXIE successfully completed all of its technical requirements and was operated at a variety of conditions throughout a full Mars year, allowing the instrument's developers to learn a great deal about the technology.
"We're proud to have supported a breakthrough technology like MOXIE that could turn local resources into useful products for future exploration missions," said Trudy Kortes, director of technology demonstrations, Space Technology Mission Directorate (STMD) at NASA Headquarters in Washington, which funds the MOXIE demonstration. "By proving this technology in real-world conditions, we've come one step closer to a future in which astronauts 'live off the land' on the Red Planet."
MOXIE produces molecular oxygen through an electrochemical process that separates one oxygen atom from each molecule of carbon dioxide pumped in from Mars' thin atmosphere. As these gases flow through the system, they're analyzed to check the purity and quantity of the oxygen produced.
]]>NASA Is One Step Closer To Terraforming Mars
While Perserverance's Mars Oxygen In Situ Resource Utilization Experiment (MOXIE) has previously managed to harvest oxygen on the Red Planet, this time it went even further by doubling its production level. In a move that MOXIE's principal investigator, Michael Hecht called "the riskiest run" that the NASA team has ever pulled off, the rover raked in somewhere around 12 grams of oxygen from Mars in just 58 minutes. Pushing themselves and Perseverance to the limit, the scientists are thrilled that they challenged their original beliefs.
another note
News of NASA's latest win on Mars comes just days after it was revealed that the agency has found a way to recycle pee and other bodily fluids (i.e. sweat) into water. Another giant leap forward, this technology could elongate the time of missions in space, allowing astronauts to go farther than ever before. And don't worry – the water is totally safe to drink with one spokesperson even saying that it's cleaner than the water we have on Earth.
NASA made enough oxygen on Mars to last an astronaut for 100 minutes
worth of breathable oxygen in 2021...
Over the course of seven hour-long production runs during that year, MOXIE was able to reliably produce roughly 15 minutes of oxygen per hour in a variety of harsh planetary conditions. That added up to a total of 50 grams of oxygen in total
7 hours is a very long period of time but then again that's with next to nothing for air pressure to get a breathable air pressure.
]]>In the context of Mars, good ideas in one specialization can be helpful in others.
Your description of a CO/O2 propulsion capability based upon an electrolysis unit matches up nicely with another topic in the forum. That one was (and is) dedicated to development of CO/O2 based tools and reciprocating engines for construction and manufacturing on Mars.
SearchTerm:CO/O2 infrastructure on Mars
This topic is presumably about a system to produce oxygen on Mars.
Since I have forgotten what the topic was about, here is a snippet from Google:
The Mars Oxygen In-Situ Resource Utilization Experiment (MOXIE) is a technology demonstration on the NASA Mars 2020 rover Perseverance investigating the production of oxygen on Mars. On April 20, 2021, MOXIE produced oxygen from carbon dioxide in the Martian atmosphere by using solid oxide electrolysis.
Mars Oxygen ISRU Experiment - Wikipedia
en.wikipedia.org › wiki › Mars_Oxygen_ISRU_Experiment
About Featured Snippets
So! The natural evolution of this discussion would be a comparison of the NASA experiment and the commercial system reported in Post #53
(th)
]]>I was considering the possibility of using compressed CO/O2 as a bipropellant combination for a pressure fed rocket sled on Mars. If we can do this, we can manufacture interplanetary ships on Mars surface and launch them in a way that would never be possible on Earth. The thin atmosphere would allow bulky objects to be launched by rocket sled without too much problem from air resistance. The dV required to get from Mars surface to LMO is about 4km/s. If the rocket sled can accelerate the payload to 2-3km/s, then a minimal upper stage or the ships own propulsion system, can provide the remainder of dV needed to reach orbital velocity.
On Mars, we could feed a solid oxide electrolysis cell with liquid CO2 at a feed pressure of 200 bar. The CO/O2 gas stream emerging from the electrolysis unit would then have sufficient discharge pressure to feed the propellant tanks directly, without compression.
The propellant tanks would need high strength to weight ratio to make use of compressed gas fuels and still retain sufficiently high mass ratio at a burn out velocity of 2.5km/s. A basalt fibre wound carbon steel tank looks promising.
]]>o burn its fuel, a rocket must have more oxygen by weight. Getting four astronauts off the Martian surface on a future mission would require approximately 15,000 pounds (7 metric tons) of rocket fuel and 55,000 pounds (25 metric tons) of oxygen. In contrast, astronauts living and working on Mars would require far less oxygen to breathe. “The astronauts who spend a year on the surface will maybe use one metric ton between them,” Hecht said.
Hauling 25 metric tons of oxygen from Earth to Mars would be an arduous task. Transporting a one-ton oxygen converter – a larger, more powerful descendant of MOXIE that could produce those 25 tons – would be far more economical and practical.
Mars’ atmosphere is 96% carbon dioxide. MOXIE works by separating oxygen atoms from carbon dioxide molecules, which are made up of one carbon atom and two oxygen atoms. A waste product, carbon monoxide, is emitted into the Martian atmosphere.
The conversion process requires high levels of heat to reach a temperature of approximately 1,470 degrees Fahrenheit (800 Celsius). To accommodate this, the MOXIE unit is made with heat-tolerant materials. These include 3D-printed nickel alloy parts, which heat and cool the gases flowing through it, and a lightweight aerogel that helps hold in the heat. A thin gold coating on the outside of MOXIE reflects infrared heat, keeping it from radiating outward and potentially damaging other parts of Perseverance.
In this first operation, MOXIE’s oxygen production was quite modest – about 5 grams, equivalent to about 10 minutes worth of breathable oxygen for an astronaut. MOXIE is designed to generate up to 10 grams of oxygen per hour.
seems that the design is way off if all that was made is 5.4 grams of oxygen in one hour and if that is roughly 10 minutes of breathable air for a human being. so we need 6 of these operating 24/7 to even break even for requirement for a person.
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At typical Martian temperatures, CO2 is close to its triple point temperature of ~220K. This makes CO2 compressible with relatively little pumping power. With the CO2 removed as a liquid, we could then cryogenically cool the remaing N2, Argon, CO and O2, until they selectively liquefy. Hence, without any chemical reactions, we could extract CO and O2 from the Martian atmosphere. Making methane can then proceed using the reverse gas shift reaction to produce hydrogen, which is then reacted with CO.
I would propose using an axial compressor to compress the Martian atmosphere up to pressures of 5 bar and then a piston compressor, which will compress and liquefy the CO2, with each cylinder having a drain. The axial compressor should face into the wind to ensure a steady flow rate into the fan. The liquid CO2 should be vapourised using waste heat from the KRUSTY and used to drive the axial compressor by passing the hot gases through a gas turbine. The axial compressor will need to be started using an electric motor.
Average wind speed on Mars is 10m/s and atmospheric density in the northern hemisphere is about 0.015kg/m3. That equates to an average of 0.015kg/m2/s incident on each square metre of the turbofan inlet. Of this, 0.075% by volume is CO. This amounts to 0.07 grams / m2 /s. A circular inlet, some 2m in diameter, would gather an average of 0.22 grams / second. That is 7 tonnes per year. How much CO do we need, to make all of the propellant needed by the Starship?
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