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"It's true it has no magnetic field but then it doesn't really need one. Park a suitably sized reflector at it's L1 point and you're good to go." Please explain the science of this.
Any two large bodies where one orbits the other have what are called Lagrange Points (five of them) which are positions in space where the gravity of both cancel each other out and something put there stays there and doesn't drift out. The L1 point is the one directly between the primary and the secondary body and always stays there. The Earths L1 point is currently the home of the NASA Solar observatory a satellite which studies the Sun. It's L3 point which is on the other side of the secondary body contains several deep space observatories the most famous of which is the James Webb telescope. You could place a thin shield of reflective foil (few thousand km across at most) at Mars L1 point with opening/closing panels and shut them whenever a solar storm was imminent. A thicker atmosphere would protect against day to day radiation. The same idea has been mooted for terraforming Venus place a sunshield at its L1 point and block sunlight eventually Venus would cool and the C02 atmosphere would sublimate out.
These aren't my ideas by the way much though I would like to claim credit you can find articles about them if you look online though I can't remember exactly where I saw them (I think there is a youtube video about the Venus one though)
 
IF we are going to create a permanent human settlement on another body, then why do advocates of this ignore the elephant in the night sky: the Moon? Would it not be much easier to colonise a place that can be reached in a couple of days, rather than nine months or more?
Mars has more existing atmosphere and water than the moon
 
So why would a refuge on Eath not contain the same mix.

If we are to build a special habitat to protect humans agtainst a hostile environment, it would be far easier to build a couple on Earht than one or two on Mars.
1. There's absolutely NO guarantee that a refuge on Earth would survive a cataclysmic asteroid strike, no matter how well it was constructed and
2. Take a look at who was building private nuclear bunkers in the 80s. Rich people.
 
Any two large bodies where one orbits the other have what are called Lagrange Points (five of them) which are positions in space where the gravity of both cancel each other out and something put there stays there and doesn't drift out. The L1 point is the one directly between the primary and the secondary body and always stays there. The Earths L1 point is currently the home of the NASA Solar observatory a satellite which studies the Sun. It's L3 point which is on the other side of the secondary body contains several deep space observatories the most famous of which is the James Webb telescope. You could place a thin shield of reflective foil (few thousand km across at most) at Mars L1 point with opening/closing panels and shut them whenever a solar storm was imminent. A thicker atmosphere would protect against day to day radiation. The same idea has been mooted for terraforming Venus place a sunshield at its L1 point and block sunlight eventually Venus would cool and the C02 atmosphere would sublimate out.
These aren't my ideas by the way much though I would like to claim credit you can find articles about them if you look online though I can't remember exactly where I saw them (I think there is a youtube video about the Venus one though)
How would you stop the cosmic rays and the daily continuous emission of hard radiation from the Sun which takes place outside solar storms?
 
1. There's absolutely NO guarantee that a refuge on Earth would survive a cataclysmic asteroid strike, no matter how well it was constructed and
2. Take a look at who was building private nuclear bunkers in the 80s. Rich people.
The refuge would not have to suvive a direct hit of the asteroid. It would be a place where peole could survive the conditions created by the asteroid strike. There would have to be two refuges, in different parts of the world, in order to obviate the possiblity of a direct hit on it.
If there would be a mixture of people on Mars, then there is no reason that there could not be a mixture of people in the refuges. There would have to be mixture of people in order to continue civilisation.
 
How would you stop the cosmic rays and the daily continuous emission of hard radiation from the Sun which takes place outside solar storms?
Mars is more than half again the distance from the Sun that Earth is, so the good old inverse square rule means that it's less than half what Earth gets anyway. In the longer run the atmosphere of a terraformed Mars will do the job, in the short run I imagine that the Martian colonists will build their cities largely underground. Living underground doesn't mean in some pokey cave. There is no reason why things like parks and boating lakes can't be constructed underground.
 
Mars is more than half again the distance from the Sun that Earth is, so the good old inverse square rule means that it's less than half what Earth gets anyway. In the longer run the atmosphere of a terraformed Mars will do the job, in the short run I imagine that the Martian colonists will build their cities largely underground. Living underground doesn't mean in some pokey cave. There is no reason why things like parks and boating lakes can't be constructed underground.
It sounds a wonderful life.
 
Looking forward to reading this when it comes out in paperback


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According to this review, the authors explain why Mars settlement should remain a fantasy for now:

Self-described “science geeks,” the Weinersmiths embarked on this book expecting to write “a sociological road map” to building off-world colonies in the near future. But as they dived into their research, they found that the loudest advocates for space settlement are so dazzled by the beauty of their rockets that they wave away “the stuff regular lives are made of,” like food and birth, democracy and law. The main problem, the Weinersmiths write, is that “Space is terrible. All of it. Terrible,” adding: The Moon isn’t just a sort of gray Sahara without air. Its surface is made of jagged, electrically charged microscopic glass and stone, which clings to pressure suits and landing vehicles. Nor is Mars just an off-world Death Valley — its soil is laden with toxic chemicals, and its thin carbonic atmosphere whips up worldwide dust storms that blot out the sun for weeks at a time. And those are the good places to land.

Life on Earth is hard. It always has been. But mankind has no problems that would be solved by relocating to a place without food, water or air. As the Weinersmiths write, “An Earth with climate change and nuclear war and, like, zombies and werewolves is still a way better place than Mars.”



But they also make a case for future settlement:

Throughout, the Weinersmiths advocate for a colonization approach that they call “wait and go big.” Fund hundreds of biospherelike experiments on Earth to learn about human survival in a closed habitat. Do systematic studies of animal reproduction in orbit, so we can find out if it’s even safe for people to get pregnant away from Earth. Modernize space law and establish a regulatory agency to ensure that the cosmos is treasured like Antarctica, not savaged like the Amazon. Once the framework is in place, move hundreds of thousands of settlers all at once — enough to establish a real civilization. Enough to thrive.

I think cities on Mars are likely to forever remain in the realm of sci-fi but whatever anyone thinks about the feasibility, we can all probably agree that a Mars society founded and controlled by Elon Musk would be the most toxic shithole in the known galaxy
 
Solar flares.

If there had been a solar flare during one of the Apollo Moon voyages and landings, the crew would have been subjected to high levels of ionising radiation, which could have caused them to suffer cancer in years to come.
This was why a watch was kept on the Sun, to try to establish that a flare was unlikely during the Apollo Moon missions.

The Apollo missions lasted days. A voyage to Mars and back would take at least 18 months. During this time it is highly likely that there would be a solar flare. To adequately shield a crewed Mars craft would make it too heavy to be feasible, or so I believe.

I remember this issue being discussed some years ago, and some people asserting that the risk of cancer was one worth taking for embarking on an expedition to Mars. I am not sure if thousands of colonists would agree.
 
Solar flares.

If there had been a solar flare during one of the Apollo Moon voyages and landings, the crew would have been subjected to high levels of ionising radiation, which could have caused them to suffer cancer in years to come.
There were flares, just not Earth directed or of sufficient intensity (Apollo 16 experienced the highest levels from such). The Apollo missions were lucky. Dose rates were relatively low in that particular solar cycle, despite it being at/around solar maximum, but also because it was at/around solar max.

Whilst increasing the risk from Sun-originated particle events, solar maximum actually helps protect against galactic cosmic ray dose (reduces it by a factor of over 2 relative to that at solar minimum), and most of the time the main contributions to dosage at/near the lunar surface are galactic in origin, followed by a secondary radiation due to a proton albedo (arising from nuclear evaporation in the regolith driven by those same galactic cosmic rays). Solar particle events contribute to dosage on a much more irregular basis.

In fact, most of the dose the Apollo astronauts received (less than most medical CT investigations) was due to time spent traversing the van Allen belts (Apollo 14 clocking up the most there). That was still somewhat over-amped at the time due to earlier exoatmospheric nuclear testing (Starfish Prime).

Between Apollos 16 and 17 there was a large solar event which would have been a problem if there had been an Apollo mission underway at the time. The astronauts of such wouldn't have suffered cancer years later though. The dose rate there would have been high enough (about 1000 times that experienced during any of the actual missions) to most likely have caused death following acute radiation sickness within days to weeks (essentially failure of the immune system, blood formation and clotting, GI tract damage and, consequently death arising from fluid loss, nutritional impairment, infection and internal bleeding).
This was why a watch was kept on the Sun, to try to establish that a flare was unlikely during the Apollo Moon missions.
The Sun is (and was) monitored routinely for a whole host of reasons, not least to better model the underlying physics.
 
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There were flares, just not Earth directed or of sufficient intensity (Apollo 16 experienced the highest levels from such). The Apollo missions were lucky. Dose rates were relatively low in that particular solar cycle, despite it being at/around solar maximum, but also because it was at/around solar max.

Whilst increasing the risk from Sun-originated particle events, solar maximum actually helps protect against galactic cosmic ray dose (reduces it by a factor of over 2 relative to that at solar minimum), and most of the time the main contributions to dosage at/near the lunar surface are galactic in origin, followed by a secondary radiation due to a proton albedo (arising from nuclear evaporation in the regolith driven by those same galactic cosmic rays). Solar particle events contribute to dosage on a much more irregular basis.

In fact, most of the dose the Apollo astronauts received (less than most medical CT investigations) was due to time spent traversing the van Allen belts (Apollo 14 clocking up the most there). That was still somewhat over-amped at the time due to earlier exoatmospheric nuclear testing (Starfish Prime).

Between Apollos 16 and 17 there was a large solar event which would have been a problem if there had been an Apollo mission underway at the time. The astronauts of such wouldn't have suffered cancer years later though. The dose rate there would have been high enough (about 1000 times that experienced during any of the actual missions) to most likely have caused death following acute radiation sickness within days to weeks (essentially failure of the immune system, blood formation and clotting, GI tract damage and, consequently death arising from fluid loss, nutritional impairment, infection and internal bleeding).

The Sun is (and was) monitored routinely for a whole host of reasons, not least to better model the underlying physics.
Thanks for that. Therefore, a Mars mission would be problematic indeed, for the crew of the spaceship.
 
We are never, ever, going to colonise another world in any meaningful sense. Establish a small, cramped, scientific base station on the moon or Mars? Maybe. Anything else is pure fantasy.
What a small, cramped, dismal view of humanity's future. And stated with such confidence.

Our species appears, so far, to be the only sentient presence within our light cone. Don't get me wrong, I would be thrilled if we found some signs of ET. But there's nothing. Just silence. No visible signs of engineering modifications to stars or planets. No echoes of gravity waves from malfunctioning warp drives (some recent work looked into this). No exhaust plumes from slower than light spacecraft, nor weird physics effects from FTL. Also we, indigenous Earth-grown humans are here; suggesting that the Earth, a pretty tasty bit of galactic real estate, has not been visited and colonised in the past billion years or so.

I suspect that the universe is teeming with "god's snot" (from SF writer Ken Macleod), that is simple lifeforms, but there is no arrow inexorably pointing towards greater intelligence, and so we could be the only sentients. What a shame if the only creatures who are intellectually or "spiritually" capable of grasping and appreciating the cosmos were to turn their back on its splendour and then, a little way further down the road, inevitably fizzle out.

No doubt it will be difficult to spread out, first to the planets, and then beyond. Methods to address the various hazards and objections mentioned above, have been devised by space agencies, researchers and companies, and documentation of such is freely available online, so I won't do the homework for you - I'm cognisant of Brandolini's law. But it is worth bearing in mind that what appears almost impossible now, will be tractable in the near future, without needing any Sci Fi arm-waving. AI/robots, supercheap launch, and biomedicine progress are all reasonably foreseeable.

I hope for a grander future, and Carl Sagan, who sure knew how to turn a phrase, puts it better than me:

“For all its material advantages, the sedentary life has left us edgy, unfulfilled. Even after 400 generations in villages and cities, we haven’t forgotten.

The open road still softly calls, like a nearly forgotten song of childhood. We invest far-off places with a certain romance. This appeal, I suspect, has been meticulously crafted by natural selection as an essential element in our survival.

Long summers, mild winters, rich harvests, plentiful game—none of them lasts forever.

It is beyond our powers to predict the future. Catastrophic events have a way of sneaking up on us, of catching us unaware. Your own life, or your band’s, or even your species’ might be owed to a restless few—drawn, by a craving they can hardly articulate or understand, to undiscovered lands and new worlds.

Herman Melville, in Moby Dick, spoke for wanderers in all epochs and meridians: “I am tormented with an everlasting itch for things remote. I love to sail forbidden seas…”

Maybe it’s a little early. Maybe the time is not quite yet. But those other worlds— promising untold opportunities—beckon. Silently, they orbit the Sun, waiting.”


― Carl Sagan


 
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We are never, ever, going to colonise another world in any meaningful sense. Establish a small, cramped, scientific base station on the moon or Mars? Maybe. Anything else is pure fantasy.

Never, ever?

Maybe not in the next few generations, but if humankind survives the strife on earth, who knows?

My worry is that we could fuck up other planets, but to state we will never ever get out into the stars... must disagree.
 
Thanks for that. Therefore, a Mars mission would be problematic indeed, for the crew of the spaceship.
Good job no one has ever stated otherwise. And as history has proven many times over, insurmountable challenges can be defeated as technology advances.
 
Never, ever?

Maybe not in the next few generations, but if humankind survives the strife on earth, who knows?

My worry is that we could fuck up other planets, but to state we will never ever get out into the stars... must disagree.
I'm intrigued. How would you go about fucking up, for instance, Jupiter ? Seems like a big job.

More seriously, what does it actually mean to "fuck up" any uninhabited, lifeless ball of gas and rock ? The Moon for instance, sports more than a million impact craters greater than 1km in diameter, and is baked, frozen and irradiated. Can we do worse to it ?
 
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We are never, ever, going to colonise another world in any meaningful sense. Establish a small, cramped, scientific base station on the moon or Mars? Maybe. Anything else is pure fantasy.
We're not going to fix the problems we have here if we think we can run away from them. This nonsense about colonising other planets should be scrapped, and we should concentrate of what we have here, as it's the only planet we have or likely ever will have.
 
Good job no one has ever stated otherwise. And as history has proven many times over, insurmountable challenges can be defeated as technology advances.
I agree that we may be able to overcome these challenges, but Musk's claims that we will be going to Mars in a couple of years are far-fetched.
 
What a small, cramped, dismal view of humanity's future. And stated with such confidence.

Our species appears, so far, to be the only sentient presence within our light cone. Don't get me wrong, I would be thrilled if we found some signs of ET. But there's nothing. Just silence. No visible signs of engineering modifications to stars or planets. No echoes of gravity waves from malfunctioning warp drives (some recent work looked into this). No exhaust plumes from slower than light spacecraft, nor weird physics effects from FTL. Also we, indigenous Earth-grown humans are here; suggesting that the Earth, a pretty tasty bit of galactic real estate, has not been visited and colonised in the past billion years or so.

I suspect that the universe is teeming with "god's snot" (from SF writer Ken Macleod), that is simple lifeforms, but there is no arrow inexorably pointing towards greater intelligence, and so we could be the only sentients. What a shame if the only creatures who are intellectually or "spiritually" capable of grasping and appreciating the cosmos were to turn their back on its splendour and then, a little way further down the road, inevitably fizzle out.

No doubt it will be difficult to spread out, first to the planets, and then beyond. Methods to address the various hazards and objections mentioned above, have been devised by space agencies, researchers and companies, and documentation of such is freely available online, so I won't do the homework for you - I'm cognisant of Brandolini's law. But it is worth bearing in mind that what appears almost impossible now, will be tractable in the near future, without needing any Sci Fi arm-waving. AI/robots, supercheap launch, and biomedicine progress are all reasonably foreseeable.

I hope for a grander future, and Carl Sagan, who sure knew how to turn a phrase, puts it better than me:

“For all its material advantages, the sedentary life has left us edgy, unfulfilled. Even after 400 generations in villages and cities, we haven’t forgotten.

The open road still softly calls, like a nearly forgotten song of childhood. We invest far-off places with a certain romance. This appeal, I suspect, has been meticulously crafted by natural selection as an essential element in our survival.

Long summers, mild winters, rich harvests, plentiful game—none of them lasts forever.

It is beyond our powers to predict the future. Catastrophic events have a way of sneaking up on us, of catching us unaware. Your own life, or your band’s, or even your species’ might be owed to a restless few—drawn, by a craving they can hardly articulate or understand, to undiscovered lands and new worlds.

Herman Melville, in Moby Dick, spoke for wanderers in all epochs and meridians: “I am tormented with an everlasting itch for things remote. I love to sail forbidden seas…”

Maybe it’s a little early. Maybe the time is not quite yet. But those other worlds— promising untold opportunities—beckon. Silently, they orbit the Sun, waiting.”


― Carl Sagan


"What a shame if the only creatures who are intellectually or "spiritually" capable of grasping and appreciating the cosmos were to turn their back on its splendour".
Well, the colonists on Mars won't even be able to see the splendour of the night sky without wearing a space suit.
 
"What a shame if the only creatures who are intellectually or "spiritually" capable of grasping and appreciating the cosmos were to turn their back on its splendour".
Well, the colonists on Mars won't even be able to see the splendour of the night sky without wearing a space suit.

Strawman

I was obviously referring to a future that extends far beyond Mars, which you chose to misrepresent. This is dishonest debate. What sense of achievement do you get from that ?

Also, perhaps the sky willl look pretty awesome standing in your suit on the surface of Mars, given that there will be no clouds, street lighting or atmospheric distortion.

It might look like this:



Credit: Apple TV+ excellent "For All Mankind"
 
Strawman

I was obviously referring to a future that extends far beyond Mars, which you chose to misrepresent. This is dishonest debate. What sense of achievement do you get from that ?

Also, perhaps the sky willl look pretty awesome standing in your suit on the surface of Mars, given that there will be no clouds, street lighting or atmospheric distortion.

It might look like this:



"I was obviously referring to a future that extends far beyond Mars"

Were you? You did not state that.
 
This is an excellent example of a Brandolini's Law comment, and gets a cherry on top for being so supremely lazy.

"because physics"

Have you told NASA, SpaceX, CNSA, Roscosmos, etc ? You could save them a lot of time and money.
None of them are looking any further for us to go than mars. Because physics.

Even the craft that has currently gone further than anything else has only recently left our solar system, and has taken nearly 50 years to do so. We, as a species, are stuck here. To think otherwise is pure fantasy.
 
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