You are not logged in.
Thanks for that GW.
Interesting profile, though...
https://www.ekinendustriyel.com/tube-he … xchangers/
"Advantages of Tube Heat Exchangers
They can be designed and manufactured to bear very high pressures
They have extremely flexible and steady design
They can be designed and manufactured to bear very high and very low temperatures
They are resistant to thermal shocks
They have no dimension limit
They can be used in all applications
Pressure loss is at a minimum and can be maintained at a minimum in line with the process purpose.
They can easily be disassembled and assembled back for maintenance, repair and cleaning
Easy maintenance and repair
Pipe diameter, pipe number, pipe length, pipe pitch and pipe arrangement can be altered. So, the designs of tube heat exchangers are quite flexible"
https://en.wikipedia.org/wiki/Shell_and … _exchanger
Those odd objects are shell-and-tube heat exchangers. They are not any kind of flyable hardware. They are the very heavy steel construction type of thing you see at chemical refineries. What Spacex needs them for, at Boca Chica, is a public unknown at this time.
Long term storage of manufactured cryogenic propellants requires insulated tanks, even on cold Mars. The cryogenics are far colder, especially the methane. The tanks on Starship are not insulated, so long-term storage is not feasible without the expenditure of enormous power. This is also a problem for months-long interplanetary voyages, for which we have yet to see any solution.
Any propellant plant, on Earth or Mars, will have to feature insulated storage tanks for the methane and for the oxygen, from which the tanks on the vehicle are filled right before launch. We have already seen this in action with the prototypes at Boca Chica. There is radiation heating of the tanks on surfaces and in space, and down on planetary surfaces, there is convective heating from the atmospheres (lower on Mars because of the low densities and lower temperatures), and conductive heating from the surface up the supports for the tanks.
That's just heat transfer physics, which NO ONE can get around. The in-space problem is less because there is only radiational heating to deal with. Some sort of cryocooler is the solution for that. But you do need the power to run it. For months at a time.
The videos whose links Louis so graciously provided do indeed deal with some of the problems we have seen so far in prototype testing. There is one problem no one is yet discussing: the troubles getting a relight on all intended engines. SN-15 was supposed to light 3 engines for the flip, then use 2 or even just 1 to touch down. The announcer said so during the ascent. That failed to happen: only 2 relit for the flip and touchdown.
I suspect without evidence that the failure to relight and the post-touchdown methane leak fires are related in some way. I may be wrong, but all the flights that have landed (even briefly) so far have had relight problems, and post-touchdown methane leaks.
GW
https://www.youtube.com/watch?v=scUj0UF-d-U
Interesting tanks...
Is this the sort of thing that could form part of the propellant production facility on Mars. It would be like Musk to kill two birds with one stone but (a) would they fit in a Starship and (b) even if they could how would you get them out to the surface but (c) could they stay inside the Starships but (d) why not just use the rocket propellant tanks in the Starships for storage?
I'm not making much sense am I!
Blake at Reddit took 14% on the basis of the higher figure for nominal power.
The data factsheet claims "Nominal power[W / m2]100-140" .
https://flisom.com/wp-content/uploads/2 … terial.pdf
It clearly states Watts per Square Metre so I've no idea where you get your 70 watts per square metre figure from.
I think it's reasonable to use 14% on the basis that there is money to throw at this. But even if it were only 10%, the whole system would still be very viable.
Even if the lower, 10% figure was applicable, the total mass of the PV system (without electrical connectors and packaging) would rise from a mere 14 tons to 19.6 tons (that's using rolls - lower tonnage if using tilted panels that would be more difficult to deploy).
Japan and Germany both have armed forces. In Japan they are referred to as "Self Defence Forces" as they are not supposed to have an army.
An interesting thing here, the Cosmonaut Survival Gun
https://en.wikipedia.org/wiki/TP-82_Cos … val_pistolat one time the Russians and Soviets before the break up of the USSR used a specific gun for space, i guess to help suvive in case the landed in a place with Bears and Wolf...later
'the TP-82 had become unusable'
Also to take not of Japan and Germany, both de-militarized but spending less on arms and perhaps both having enjoyed the benefits of protection from the US
It's a bad idea. In Australia prisoners were used in simple forced labour tasks and then freed to farm. On Mars we need mostly people with high level skills and we can't afford to have any nihilistic elements or people who can't act with self-discipline. People are expected to behave with quite a high level of self-discipline in other dangerous environments e.g. pressurised aircrafts or ships at sea. Behaviour that endangers everyone else cannot be accepted.
For better or worse, Mars is going to be a different type of metropolis from the sort we are used to on Earth. People with criminal traits will simply be returned to Earth.
Over time, it may become more like Earth, because it won't be able to "export" its problems back to Earth.
Louis,
Isn't it funny how engineers are always focused on thermodynamics, energy density, power-to-weight ratio, and structural integrity? It's almost as if those were the scientific principles that made all combustion engines and nuclear reactors and solar panels work, that made aircraft fly, that made wind turbines generate power from aerodynamic lift, that took the first humans to the moon...
The one society that tried to achieve everything through engineering was the Soviet Union. Bridges, dams and canals galore. A world leader in rocket design and space exploration.
And a very poorly functioning economy.
There is more to successful economic development than just engineering.
You keep trying to apply belief and ideology to this power generation problem because you're enamored with the idea, I think because photovoltaics are a "shiny new object of affection", as if one could "will away" the basic physics that govern how well any power generating solution actually works. I keep focusing on the implementation of the idea, because that determines whether or not people live or die. For the record, I'm very happy about the fact that the photons are delivered free to my door. I have no complaints about that part of the energy equation. It's the quantity that is delivered and the conversion efficiency that needs to improve. We can't do much about the former, but we can use those scientific principles to improve the latter.
I don't mind admitting that I am enthused by the idea of solar energy. However, if there were coal and freely available oxygen on Mars I would say burn it. Any pollution would not harm humans, confined to indoors and it would help terraform the planet a little bit.
I get the feeling that you keep "throwing stuff at the wall", to see if anything sticks, as part of a concerted effort to ignore what's so obvious, because you don't like what it means. Amongst others here, I keep trying to drive home the fundamental "maths" that govern how well the solution works, because that is what "makes it go", no matter what solution is ultimately used. Why else do you suppose I keep harping on the same basic points? I have more of my own money invested into solar power than I do in any other form of power except combustion engines, so it wouldn't be congruent to suggest that I don't like both technologies. However, I also accept current limitations. Have you even considered the possibility that I understand enough about the basic design principles behind the available technologies involved to know what is and what isn't a practical solution?
Throwing stuff at the wall is not a bad idea when faced with novel and demanding challenges. That approach is what initially made PV energy a contender. We are faced with novel and demanding challenges on Mars.
You haven't commented on the suggestion of using commercially available Flisom CIGS e-film as the starting point for a Mars based system. Flisom indicate it is suitable for space applications. Blake at Reddit put forward proposals for encapsulation and deployment giving a figure of 150 grams per square metre. If feasible that drastically reduces the mass requirement
https://flisom.com/wp-content/uploads/2 … terial.pdf
Japan in general was already a high-growth place by the 1700s, but the Tenmei Famine in the 1780s reduced the population of a Japan by around a million people. The weather turned cold and since they lacked an abundance of that master resource and all the associated technologies that stemmed from it, entire towns and villages of people died as a result.
Whatever, they had a million person city without fossil fuels or nuclear power.
All human life will cease to exist in less than 15 minutes pretty much anywhere else besides Earth, if there's ever a problem with the energy supply. Nobody has to get sick, crops don't have to fail, and no war need be started. A single faulty microchip that cuts the flow of electricity for much longer than a few minutes is all it would take without extensive backups and preparations to ensure that that never happens. Much like living on a planet that is not naturally habitable for humans, nuclear power is a double-edged sword. It can give or take life rather quickly. However, a heat engine is also so simple and reliable that it will literally last a human lifetime. Nuclear reactors have been in continuous operation for longer than thin film or triple junction photovoltaics have existed. In point of fact, more than a few of these reactors were generating power before mass production of semiconductors of any kind. All these decades later, they're still operating. No photovoltaic anything has lasted so long in service.
Sublimation engines have been demonstrated on Earth in the lab. I think that is definitely a route that will be investigated on Mars.
https://www.extremetech.com/extreme/200 … tion-maybe
I believe that solar power has tremendous potential, if even some of the fundamental problems are solved, but concerted worldwide effort spanning decades has yet to produce commercial products with the technical characteristics required. As such, we either need more effort focused on solving those problems (power output per unit weight over unit time, performance under LILT conditions, cell degradation / service lifespan improvement) or we need an alternative technology that continues to produce power with or without sunlight, with or without temperature fluctuations, etc. For example, if we had solar cells that lasted for, say 50 years, that would drastically improve the value proposition of using something like thin film, even at the expense of performance. Until then, I'm proposing other realistic alternatives that do not impose such a long string of "IFs" into the power generating solution. Both nuclear thermal and solar thermal appear to be better alternatives.
This is a bit like saying "It will be impossible to set up the large industrial factories we have on Earth to make things. Therefore it will be impossible to make things." Mars colonisation calls for new approaches. The most obvious is using 3D printers and industrial robots so we can create a scaled down industrial infrastructure. This won't be as efficient as producing items by the million in dedicated factories but it will meet the challenge of living on Mars.
Likewise with the energy system. PV energy will be less efficient on Mars but it will be capable of meeting our needs. To a certain extent, the absence of adverse weather on Mars and the ability to use higher efficiency panels will compensate for being further from the Sun.
Our material needs will be greater in some respects (life support and pressurisation) but far less in others: no need to produce paper, private vehicles, metalled roads, all that road signage, railways, ports, bridges, ocean going ships, aeroplanes or military weapons, no need to sink huge resources into welfare and care for large numbers sick people (at least for the first few decades) and no need to support a vast governmental bureaucracy. I've never done a proper calculation before but I wouldn't be surprised if what I've just listed amounts to over 50% of your average advanced economy.
It's worth reading through but I am getting the impression it must be the work of students. It seems rather jejune, naive.
The assumption that all countries on Earth will share their enthusiasm for turning Mars into a beacon of free enterprise is one such example. CCP China will want to dominate Mars as it seeks to dominate Earth. Powerful religions will want to project their religious dogmas on to Mars. Big Tech will want to make Mars a place safe for billionaires. They would be swimming with sharks, while thinking they are in a play pool!
I like the Marsha habs. But the idea that each crew member should have their own Marsha house as that will reduce crew fiction is very simplistic! Crew friction is more likely to arise I think if everyone does have their own place...status immediately becomes an issue.
I don't recall seeing the JAXA-Toyota rover design before. It does look like it has been designed for long range exploration, so interesting.
Some of it just doesn't make sense e.g. on the one hand they say the base will be in Arcadia Planitia with plenty of sub-surface ice around on the other, they seem to be talking terms of transporting water ice from the North Pole cap. There's is plenty of water ice at the boundary of Arcadia Planitia and Amazonis Planitia where JPL has identified suitable landing sites.
Page 7 - "throughout Phase 1, various reusable rocket flights to the Moon and back will take place to test our technologies and procedures in close cooperation with our main partner, SpaceX."
This is rather fascinating! Are they actually partnered with Space X then? All may yet be revealed...
Page 8 - "This [international lunar] outpost will serve as both a refueling station and a launch-pad to send our first supplies to Mars in 2033."
Not sure why you'd need the Moon for this purpose. They are proposing resource extraction on the Moon...but what can you find on the Moon that you can't find on Earth or Mars? I find this proposal unconvincing.
The seem to view the lunar outpost as a potentially lucrative source of materials for sale back on Earth (even with a cheap Starship, that ain't gonna work) as well as the perfect testing ground for a Mars Mission. They go on to say:
Page 12 - "In the long-term scope of our mission, with the resources we see necessary to bring with us to Mars, the Moon outpost will be a fruitful investment that will greatly help us lower down thetotal mission costs of making a Martian colony. The Moon not only offers cheaper launch costs, but also has plenty of natural resources we can strategically take advantage of. "
I am not convinced at all by this lunar outpost. It seems like a huge diversion of resources into doing things on the Moon which we can do on Mars. People on Earth have a proprietary feel about the Moon. You can't assume people are going to be happy with you digging up the lunar surface for commercial extraction. This seems a shaky and possibly fatal start to the Mission.
Lunar involvement in the Mars Mission should be kept to the absolute minimum - essentially testing out coms, habs and so on. A lot of testing can be done on Earth, just as all the testing for the Mars Rovers was done on Earth.
Just opening this thread for discussion of a lengthy paper by Kufel, Zampedri, Reiss and Friesch of Loyola Marymount University. Apparently it got a thumbs up from Elon Musk...
https://digitalcommons.lmu.edu/cgi/view … ntext=ulra
Page 7 "The Moon provides an ideal setting for ensuring our readiness for this. It is significantly closer to us than the red spherewith a travel time of a few days instead of months, and replicatesmany of the obstacles we will face on Mars."
Hmmm...yes, to a degree, but no to a more significant degree. It's an entirely different sort of celestial body with a totally different sort of day-night profile and no atmosphere. In many ways parts of Earth - eg dry rocky deserts - are a better model for what we face on Mars.
The moon does provide us with an opportunity to test potential crew members - maybe have them in zero G for a month and mayb e testing out cargo unloading on the Moon might be helpful.
OF might find this useful for comparison. I haven't been through it yet...
We're talking about Mission One, right? I don't see a large work requirement for "construction".
Surely you would use Bigelow-style inflatables. These might need to be towed to the base location (some way from the nascent spaceport). The inflatable habs need integrated airlocks big enought to accommodate a small human rover, similar to NASA's Mars rover).
Personally I would favour double airlocks - a large external big enough to house the rover. You'd probably take along a couple of rovers. At about a couple of tons each that won't take up much mass.
For Mission One I think you'd probably have a small inflatable hab to house people while the main buildings are put up.
I can't see why all the habs wouldn't be inflatables. You might have two (or more) residential habs, an experimental farm hab producing salad crops. Maybe an electrical connector hab, to make monitoring and maintenance easier? Maybe a science hab for collecting and examining specimens. Lastly, maybe an industrial hab for 3D printers, experimental furnace and experimental construction techniques.
How the propellant production facility created is probably the main question.
Furnishings for the hab would be pretty much auto-assembly I think.
For SpaceNut re Mars Expedition 17 crew members
I went back and re-read Post #1 ... Your vision of the topic as a kind of Wiki is interesting.
My vision for Oldfart1939's work is that it would develop into an article that could be published in a mainstream periodical, at the level of Popular Mechanics or Analog, or (stretching) Scientific American or Discovery or (really stretching) National Geographic.
Your vision of a Wiki format is compatible with all of those.
In the Companion topic, in Post #65
(th)-
I was hoping for some commentary and input on my latest post of the 17 astronaut crew thread.The time of Post #65 was 2021-05-18 18:53:03
Working backward, the latest post in the primary topic was #10 at 2021-05-17 12:52:33
Some self-criticism and evaluation: everyone on the mission will be physically fit and able to pitch in with construction at least 4 hours of their on-duty shifts. As the base takes shape and construction of the essential habitat construction winds down, the scientists can get to work doing science, and the geologists doing the bulk of exploration and looking for water and other useful minerals for base use.
After the initial construction phase requires less input from the construction triads, they can be utilized in the greenhouse and food growing business. There will be a LOT of work in setting up the base, and why I'm self-critical is that the workers will be initially overloaded and scientists, geologists, and medical staff will be somewhat underutilized.Let's think about this specific text, in the context of wanting to assist Oldfart1939 as best we can, as he takes on this enormous task.
Let's think about each sentence, and comment specifically on that.
1)Some self-criticism and evaluation: everyone on the mission will be physically fit and able to pitch in with construction at least 4 hours of their on-duty shifts.
2)As the base takes shape and construction of the essential habitat construction winds down, the scientists can get to work doing science, and the geologists doing the bulk of exploration and looking for water and other useful minerals for base use.
3)After the initial construction phase requires less input from the construction triads, they can be utilized in the greenhouse and food growing business.
4)There will be a LOT of work in setting up the base, and why I'm self-critical is that the workers will be initially overloaded and scientists, geologists, and medical staff will be somewhat underutilized.
(th)
Weirdo robosound but interesting:
My attitude to the Moon is very different from that towards Mars or indeed the asteroids.
I think the Moon needs quite heavy protection, similar to the Antarctic Treaty. I think mining activities on the Moon would need to be carefully regulated. Likewise we need to preserve the landing sites for US, Russian and other missions. We need to protect the appearance of the Moon as well, given its cultural significance. There's probably a strong argument for locating any urban development on the Far Side of the Moon and ensuring lighting on the Moon is never visible from Earth.
Exploitation of asteroids is fine in my book.
Mars, I want to see turned into a sovereign planetary republic as soon as possible which can then look after itself.
https://trumpwhitehouse.archives.gov/pr … resources/
The arguement that what you mine is yours but you should not take the last shovel full as then the celestal body is gone problem...
Fine but you must use it there and not bring it anywhere...
I went to their website. An annoying lack of technical spec detail. Just vague claims like "have an impressive weight to power ratio".
Looks good in the photos but I've no idea what they are offering really and a production run of 42,000 sq metres doesn't sound that big.
I hope we can nail down what they are offering.
For Louis re topic ...
https://www.yahoo.com/news/polish-firm- … 05470.html
Stanislaw WASZAK
Fri, May 21, 2021, 9:35 AM
In this article:Olga Malinkiewicz
Polish physicistA Polish company on Friday launched the world's first industrial production line of solar panels based on groundbreaking perovskite technology, which could revolutionise access to solar power.
Named after the Baltic goddess of the sun, Saule Technologies makes sheets of solar panels using a novel inkjet printing procedure invented by company founder Olga Malinkiewicz.
"We're scaling up, going from laboratory to production line," said Malinkiewicz, whose firm is based in the southern city of Wroclaw.
The cutting-edge technology has been in the works for close to a decade but the plant opening comes at a fortuitous time, as the EU member is experiencing a solar boom.
Also...
https://www.brown.edu/news/2021-05-06/perovskite
‘Molecular glue’ makes perovskite solar cells dramatically more reliable over time
In a study that could help to bring inexpensive, efficient perovskite solar cells one step closer to commercial use, researchers found a way to strengthen a key weak point in the cells, dramatically increasing their functional life.
Image of a solar cellResearchers have used self-assembled monolayer "molecular glue" totoughen interfaces in perovskite solar cells to make them more efficient,stable and reliable. Padture Lab/Brown University
PROVIDENCE, R.I. [Brown University] — A research team from Brown University has made a major step toward improving the long-term reliability of perovskite solar cells, an emerging clean energy technology. In a study published in the journal Science, the team demonstrates a “molecular glue” that keeps a key interface inside cells from degrading. The treatment dramatically increases cells’ stability and reliability over time, while also improving the efficiency with which they convert sunlight into electricity.
(th)
I beleive the OST is best left alone now. Any replacement treaty would impose bureaucracy on space exploration and, specifically, Mars colonisation.
The OST does not prevent setting up human bases on Mars or indeed people settled on Mars from declaring themselves a sovereign people and territory, as is their general right under the UN Human Rights Declaration. It prevents states - and companies operating from Earth states - in claiming ownership of land.
As long as property title is avoided and only a system of licensed usage for pre-determined periods maintained, then the OST is no bar to settlement.
An Antarctic style treaty for the Moon would be acceptable, in my view, with various safeguards e.g. no facilities being created that are visible from Earth, no stationing of weapons.
It's a joy ride not a space flight! This isn't the future of space tourism.
Virgin Galactic and Branson. Virgin Galactic Makes First Flight To Space From New Mexico Base As It Prepares To Carry Tourists Next Year https://www.forbes.com/sites/joewalsh/2 … next-year/
The question I ask is: "do we want the Moon to be illuminated with a sign saying Cocal Cola"? The vast majority of humanity would answer no, I believe.
While I have no animus against Trump I think there does have to be some restraint on "free enterprise" otherwise it can interfere with our freedoms (as we see now with Big Tech censorship of perfectly acceptable views). As I recall the Moon Treaty was pretty rubbish but I believe, given its proximity to Earth and its cultural significance in every society it does need protecting.
NASA Boss Bill Nelson Says China 'Aggressive Competitor' After Mars Landing
https://www.newsweek.com/nasa-bill-nels … ng-1593241Also there is a Moon Treaty...the space review website once asked, a failed international law or waiting in the shadows?
https://en.wikipedia.org/wiki/Moon_Treaty
' As of January 2019, 18 states are parties to the treaty '
signatories also from France and IndiaIn 2020, U.S. President Donald Trump signed an executive order called "Encouraging International Support for the Recovery and Use of Space Resources." The order emphasizes that "the United States does not view outer space as a 'global commons" and calls the Moon Agreement a "a failed attempt at constraining free enterprise."
Presumably kbd you keep referring to the theme of energy density because you feel that's a slam dunk win but it's hardly a trump card. We could equally refer to the positives of solar e.g that the fuel, photons, is massless and delivered free to your door.
Remember, Kyoto in Japan was a million person city back in the 1700s with no fossil fuel input. That was based essentially on a huge food surplus from rice cultivation. There's more than one way to skin a rabbit, as the saying goes.
While our theoretical discussion has focussed on PV power, there are in truth other options. One would be geothermal- there may be some "hotspots" on Mars. More promising perhaps would be heat engines of various types. It does seem possible to run something like a sublimation engine on Mars, taking advantages of the huge diurnal temperature shifts (thus avoiding large energy imput to get the process going), in the same way we run steam engines on Earth, except we wouldn't have to dig out coal. Other heat engines of various types may be possible. We can also use solar reflectors to help heat and illuminate farm habs. The problem with heat engines and the like is that we need to get to Mars and set up a substantial settlement before we can "relax" and investigate all the possibilities.
As on Earth, in order to enjoy the benefits of modern civilisation, we need to first ensure there is a sizeable food surplus. Initially we are going to be constrained to practise artificial-light farming plus techniques like hydroponics and that will be expensive in terms of energy.
However, within a few years we should be able to experiment with crop growing using natural light and soil. The best suggestions I have seen involve transparent plastic structures with CO2 pumped in to a pressure about 20% of Earth's atmosphere. Heating/heat retention for the farm habs could be achieved by use of mylar style reflector blinds that cover the structure me at night, solar reflectors beaming light on to the structures during the day, waste heat from industrial processes and growing crops alongside thermogenic plants that release heat at night. On the plus side, we should be able to avoid all the energy that goes into pesticides, drainage, dealing with adverse weather events such as drought, eliminating rodents and the like on Earth. Initially we will need to put a lot of energy into making soil, but soil can eventually become sustainable through organic style farming.
Mars's land area is the same as Earth's. Once we master the challenges of producing food on Mars with low energy input using natural light and soil, we will be able to generate huge food surpluses. The number of people involved directly in agriculture will be a small percentage, probably no more than 3% of the workforce as it will be highly automated. The other 97% will be free to undertake other work. There will be no problem supporting the food consumption of a city of one million people on a planet with the same land area and nearly half the solar energy of Earth.
Louis,
I want to see a city of a million people powered solely by photovoltaics and batteries here on Earth before we attempt to achieve the same thing on another planet receiving half as many photons from the Sun.
Given that the success of human reproduction is driven almost entirely by an abundance of energy, which Mars clearly lacks, do you not think that the problem is related to that lack of abundance?
We had lots of surplus human reproduction before energy was as abundant as it is today, but the problem was that so many of those children died before they reached reproductive age that until power generation technology, thus every other technology dependent upon readily available power, caught up to where it needed to be, the results were a foregone conclusion- life was short, bleak, and brutal. Housing with sanitation and electricity, food production, and medical technology advancements were all driven by surplus energy. If we're limited to the least energy-dense resource available, namely wind and solar power, then societal growth will continue to be stunted by a lack of energy. It doesn't matter in the least how "free" the resource is, because the technologies to use those "free" resources require copious quantities of power to actually implement. That's why China produces the most solar panels of any country- they primarily use the most energy dense resources available, no matter if it agrees with anyone's ideology or not.
Well, I think a one million person city in 30 years powered by a PV system is technically possible. However, I think it is highly unfeasible in terms of social organisation and permanent migration.
My "alternative" mission is not so different. It would use Starships. I just envisage a slower path to a population of one million. I would aim for 100,000 as a potentiallly self-sufficient population. Growth beyond that sort of figure will probably require significant surplus human reproduction on the planet.
Louis,
Are we still talking about Elon Musk's goal of building a city of a million people on Mars, or some alternative mission that you, personally, want to pursue?
That guy's thinking is all over the place.
For one thing - how many people live at Mawson? A lot more than would be on Mission One I would suggest.
Somehow, although opposing solar power, he's ended up with a v low sq metre figure.
BTW - I proposed some time ago that a Mars currency should be linked to the amount of electrical output on Mars as a way of securing the value of the currency. So with 1 MwH output you can issue 1 million currency units and with 100 MwHs output, 100 million units.
Hadn't realised Arthur C Clarke had got there before me.
Numbers Louis
https://medium.com/swlh/solar-power-is- … fb221722b1
If we look at a 2031 reference mission, departing on February 22, it arrives at Mars about nine months later on November 7th, 2031. The next departure date for Earth is February 5th, 2033, leaving only 456 days to generate the return fuel, assuming that we’re generating the fuel on-demand in real time). If we leave a fifty day safety zone, this means we must produce about 2,500kg of propellant per day. Pioneer Astronautics created a prototype ISPP (In-Situ Propellant Production) plant which produces 1kg/day of propellant using 700 watts of power. If we take that number and multiply it by 2500, we get 1.75 Megawatts of power
If we plug in our numbers:
Area = 1,750,000w / 593w / 35% / 20%
Area = ~42,000 sq meters (10 acres)
.
He's wrong on 45N (this was from a few years back I believe). The recommended landing sites from JPL passed to Space X are around the 31 degree north mark - just outside the optimal zone for PV which is between 25 and 29 north in the northern hemipshere (due to Mars's pronounced wobble).
45 N on mars is not the same as on earth for power levels to receive as its even lower.
A fixed tilt if not changed as mars goes through its seasons will be even lower.
14% as it's the highest claimed in the datasheet would not serve mars very well.
https://ocw.mit.edu/courses/aeronautics … _done2.pdf
https://www.sciencedirect.com/topics/ea … insolation
https://ars.els-cdn.com/content/image/1 … 71-gr8.jpg
there is an error in the plot for the northern as it should match the southern just upside down.
For Mars, the maximum irradiance varies by ∼224 W m^2 from aphelion to perihelion, at the equator.
I'm assuming Space X can do direct coms to Earth from the Mars surface with a powerful transmitter and receiver. I doubt transmisson via satellite will be required because they are quite small transmitters in any case.
no ionosphere so coms only up and down while over head to orbiting satelites
Yes good point about cut grass and feeling it on bare feet. This is the sort of pleasurable sensory experience that needs to be part of living on Mars.
Biomes are not applicable to Mars habs which will not be closed systems. They will be open, allowing for venting of gases and vapours and intake of atmosphere/materials.
There will be many Biomes to be had on mars as is on earth and that we will want to create on mars more than trees within. Its just one such example of how different each will be.
As there will be out comes of product that will be desired from each.What Biome's are needed on Mars of which there is at least 7 maybe more
The green grass of Mars is one where we can enjoy the smell of cut grass and feel it between the toes....
I predict it will be a "thing" within 5-10 years.
They may have to protect the footprints in some sort of transparent plastic coating I think.
Obviously at some point an Apollo 11 Museum will be built near the site which will show artefacts, replicas and video. I think it will be quite a moving experience when you see it from the viewpoint of Armstrong and Aldrin - so far away from home with such "primitive" technology.
It will be the centrepiece of a lunar holiday.
It most likely will become a thing but for now the greatest journey tourists have done so far is LEO
Space tourist Yusaku Maezawa wants ideas for what to do in space
https://www.space.com/space-tourist-yus … ight-ideas
Space tourism: when could we plan a trip to cosmos?
https://www.aerotime.aero/27916-space-t … -to-cosmos
Eh? Starship will be designed to return to Mars and a single Starship could carry 100 large rovers to Mars!
Thats science not occupation if it lands whole when a single Starship can not return as it stands.
Nasa needs a return capability not another rover or lander
