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Space: A sudden light

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Re: Space: A sudden light

#41

Post by tokipin »

erikpukinskis wrote: post #34
hossbeast wrote: post #6

Earlier quoted context omitted.

Long term continuity of the human race, by backing up to another physical medium, I.e. planet

Anyone looking to invest in the long term continuity of the human race would be foolish to invest in space travel. There are practically limitless terrestrial investments which would offer much better ROI. I have yet to see anyone describe a single scenario of even low probability where Mars is more habitable than the entirety of Earth.

The idea is to have our eggs in more than one basket so that the next mass extinction event doesn't take us all out or set us back hundreds of years. Whether life on mars is fun or not is a separate question. (I do agree with you. We can barely manage to live in Antarctica. Mars will be much more difficult.)

And in becoming multiplanetary, we can start gaining the tools that could help us avoid some of those extinction events.

Re: Space: A sudden light

#42

Post by senko »

pjungwir wrote: post #17
chris_va wrote: post #9

The real problem with the space economy is that there are really very few business plans: - Space Tourism - Imagery Acquisition - Communications - Science - Astroid Mining (pending) ... And it turns out that none so far have been good businesses, and the small sat form factor is really limited. I really really love space stuff, but I don't see any of these creating explosive growth in the short term. Eventually the c…

I keep daydreaming about what a killer business might be. A few other ideas that probably won't pan out but are interesting to think about: - Since nuclear reactors are dangerous, what if we build them on the moon instead? Is there any way to generate energy there and get it back to earth? - In The Moon is a Harsh Mistress the moon-dwellers fight earth by hurling rocks (maybe just threatening?), which strike with mor…

> - Since nuclear reactors are dangerous, what if we build them on the moon instead? Is there any way to generate energy there and get it back to earth?

My pet scifi idea about it: turn Mercury (rim) into a giant powerplant, use it to create tons of antimatter, ship it to earth. Containment might be tricky tho :)

Re: Space: A sudden light

#43

Post by moreati »

extrapickles wrote: post #35
chris_va wrote: post #22

Earlier quoted context omitted.

- Zero g manufacturing ( good edit , has some potential) You have something with the spaced based solar (SBSP). The unsolved problem there is the microwave power beaming, which has some technical hurdles (synchronizing microwave frequencies across multiple dishes is apparently hard, but necessary for power beaming, and there is an ozone problem). Any other space based power system has this same transmission problem (…

Even if you solve the synchronization problem, you still have the main problem with power beaming of the massive sizes needed of the transmitter and receivers at space scale distances, thanks to diffraction. Microwaves need prohibitively large transmitter/receiver arrays if you go beyond LEO (drag is an issue in LEO). While putting a kilometer^2 scale transmitter in orbit isn't a problem, putting the similarly sized…

> putting a kilometer^2 scale transmitter in orbit isn't a problem, putting the similarly sized receiver for it on the ground is

Wow, I would have guessed the exact opposite. What's the reason(s) for the higher difficulty on the ground? Planning permission? Cost of the land? Needing multiple sites in multiple countries for non-geosynchronous orbits?

> Disclaimer: I worked with a company that does terrestrial optical power beaming.

That sounds fascinating. Could you elaborate? What's the power level and the application?

Re: Space: A sudden light

#44

Post by fapjacks »

chris_va wrote: post #9

The real problem with the space economy is that there are really very few business plans: - Space Tourism - Imagery Acquisition - Communications - Science - Astroid Mining (pending) ... And it turns out that none so far have been good businesses, and the small sat form factor is really limited. I really really love space stuff, but I don't see any of these creating explosive growth in the short term. Eventually the c…

Nobody has yet mentioned Helium-3, though it's related to your asteroid mining point. Helium-3 is used in fusion and seems to be the "free energy" replacement for petrochemicals that we need. China and the USA have both stated that they have sights set on Helium-3 mining on the Earth's moon, though China appears to be much more serious about it than the United States. I personally believe that Helium-3 will be the thing that causes a gold rush into space.

Re: Space: A sudden light

#45

Post by kiliantics »

ChuckMcM wrote: post #19
chris_va wrote: post #9

The real problem with the space economy is that there are really very few business plans: - Space Tourism - Imagery Acquisition - Communications - Science - Astroid Mining (pending) ... And it turns out that none so far have been good businesses, and the small sat form factor is really limited. I really really love space stuff, but I don't see any of these creating explosive growth in the short term. Eventually the c…

I would agree this is generally true. There isn't anything that is easier to do in "space" than it is on the planet. But I think that might not be as true for other planets. You could, for example, put radioactive waste in an open pit on the moon. Nobody is going to "accidentally walk by it unprotected" as the radiation levels on the surface of the moon are "naturally" higher than anything we've got in our waste pile…

I think this isn't a viable option because you would need 100% certainty that your flight will not fail. An explosion in the atmosphere with nuclear waste involved sounds pretty devastating. This is the same reason that nuclear power should be avoided right now. Even if the chance of disaster is tiny, the consequences are far too large.

Re: Space: A sudden light

#46

Post by erikpukinskis »

tokipin wrote: post #41
erikpukinskis wrote: post #34

Earlier quoted context omitted.

Anyone looking to invest in the long term continuity of the human race would be foolish to invest in space travel. There are practically limitless terrestrial investments which would offer much better ROI. I have yet to see anyone describe a single scenario of even low probability where Mars is more habitable than the entirety of Earth.

The idea is to have our eggs in more than one basket so that the next mass extinction event doesn't take us all out or set us back hundreds of years. Whether life on mars is fun or not is a separate question. (I do agree with you. We can barely manage to live in Antarctica. Mars will be much more difficult.) And in becoming multiplanetary, we can start gaining the tools that could help us avoid some of those extincti…

I get the idea. I'm saying we're better served by improving our Earth baskets than trying to add a Mars one. Moving 1% of your net worth out of your home currency doesn't make any sense if 99% of your money is invested in a Ponzi scheme. You want to move some of it to a safer investment before worrying about outlandish economic collapse scenarios. Not all diversification is created equal.

Not sure what you mean by extinction avoiding tools or why you think developing them on Mars will be easier than on Earth.

Re: Space: A sudden light

#47

Post by extrapickles »

moreati wrote: post #43
extrapickles wrote: post #35

Earlier quoted context omitted.

Even if you solve the synchronization problem, you still have the main problem with power beaming of the massive sizes needed of the transmitter and receivers at space scale distances, thanks to diffraction. Microwaves need prohibitively large transmitter/receiver arrays if you go beyond LEO (drag is an issue in LEO). While putting a kilometer^2 scale transmitter in orbit isn't a problem, putting the similarly sized…

> putting a kilometer^2 scale transmitter in orbit isn't a problem, putting the similarly sized receiver for it on the ground is Wow, I would have guessed the exact opposite. What's the reason(s) for the higher difficulty on the ground? Planning permission? Cost of the land? Needing multiple sites in multiple countries for non-geosynchronous orbits? > Disclaimer: I worked with a company that does terrestrial optical…

Building the structure itself isn't too hard as it will be mostly empty space. For microwave it will be an area packed with odd looking antennas, optical is basically an off the shelf solar farm (though the cells should be tuned for the application rather than general sunlight).

The hard bit getting all the regulatory ducks in a row, as you will need ground->space no fly zones, environmental approval, not be sited near anything else in case of alignment/focus/astigmatism (side lobes for rf) issues, etc. Generally out in the middle of nowhere there is some endangered animal (or its migration pattern) that will cause no end of issues regulatory wise for something this big/dangerous to wildlife unless you keep the energy density down below that of the sun (at that point you might as well use normal solar). You will also need controls to rapidly shutdown the system (or shunt to new location) in case an aircraft violates the no fly zone or another satellite is about to pass between the transmitter and receiver.

> That sounds fascinating. Could you elaborate? What's the power level and the application?

What they did when I was there was fairly diverse. The biggest was delivering 1kw at a distance of 1km with ~5-10% plug to plug efficiency. The primary application for that system was inflight refueling of electrically powered drones. They normally do much smaller/simpler (10w over dozens of meters) systems for oddball applications (eg: sensors that are sitting on something charged to 500+kv, etc) and power over fiber-optics.

Re: Space: A sudden light

#48

Post by skykooler »

pjungwir wrote: post #17
chris_va wrote: post #9

The real problem with the space economy is that there are really very few business plans: - Space Tourism - Imagery Acquisition - Communications - Science - Astroid Mining (pending) ... And it turns out that none so far have been good businesses, and the small sat form factor is really limited. I really really love space stuff, but I don't see any of these creating explosive growth in the short term. Eventually the c…

I keep daydreaming about what a killer business might be. A few other ideas that probably won't pan out but are interesting to think about: - Since nuclear reactors are dangerous, what if we build them on the moon instead? Is there any way to generate energy there and get it back to earth? - In The Moon is a Harsh Mistress the moon-dwellers fight earth by hurling rocks (maybe just threatening?), which strike with mor…

> Is there any way to generate energy there and get it back to earth?

Not only nuclear, but space is a great place for solar as well - 24-hour sunlight, with no clouds or rain. That said, it's pretty prohibitively expensive unless we can build them out of silicon-based asteroids.

Re: Space: A sudden light

#49

Post by rm445 »

chris_va wrote: post #9

The real problem with the space economy is that there are really very few business plans: - Space Tourism - Imagery Acquisition - Communications - Science - Astroid Mining (pending) ... And it turns out that none so far have been good businesses, and the small sat form factor is really limited. I really really love space stuff, but I don't see any of these creating explosive growth in the short term. Eventually the c…

It seems paradoxical. Access to amounts of matter and energy that would be absolutely transformational to the world (solar system) economy... but no economic case to go and get them?

Perhaps this is something with a huge payoff that doesn't make investing sense on anyone's time horizon because it's longer than all our lifetimes.

Still, long-lived entities (such as nation states) do exist - depending on political conditions, projects on multi-lifetime timescales can be viable. One would like to think that our far-sighted leaders would make some investment, given there's an awfully big prize up for grabs.

Re: Space: A sudden light

#50

Post by pilom »

mikeash wrote: post #16
chris_va wrote: post #15

Earlier quoted context omitted.

The problem with communication satellites is that the technology isn't as good (throughput, latency, cost) as a ground based system, except for handling coverage gaps. Coverage gaps on the ground are slowly going away, so eventually this business will likely decline.

Now you're changing from "so far" to attempting to predict the future, which is rather different. As far as the future goes, throughput and latency both improve dramatically with low-orbit systems. Cost is high (see the massive failure of Iridium to see how that can go) but is coming down pretty rapidly right now. And given how many satellite dishes I see on buildings in cities, it seems that there are use cases beyo…

>As far as the future goes, throughput and latency both improve dramatically with low-orbit systems.

The problem is that they still pare in comparison to ground based systems. On LTE, with aggregation, you can get something like 100 Mbps out of a cell phone on about >90% of the US's land area with Verizon's network. Irridium Next which doesn't even start launching until September will be limited to 8 Mbps and won't be completely ready for another couple years. Two-way LEO satellite communication will only be worth it to people on the oceans very soon. The satellite dishes on buildings only work with one way communication.

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