Nibb31

The chair could also have been from a boat, a tractor, a car, a shipping container full of seats, any other piece of wreckage or trash that's floating around in the Indian Ocean. He didn't seem to be able to determine what type of seat it was. Although aircraft upholstery is designed to float, the actual seat frames are metal and will tend to sink. How many chairs or seats do you think end up on beaches as flotsam every year in the world? Should workers around the world call the police each time they find a chair, or a handle, or any other piece of plastic that might or might not be from a ship, an aircraft, or a truck? Aviation incident investigators don't have "troops" that are capable of combing thousands of kilometers of coastlines for several years. They rely on local authorities for that.

Reunion is France. There are coast guard services, beach cleaning services, rescue services, military and gendarmerie helicopters, etc... There's a whole infrastructure in France that you won't find in Madagascar. The guy who says he probably burned stuff, or the government who employs him, aren't to blame. He probably burns tons of trash every year that he picks up on that beach, including luggage and wreckage. He's not going to call the gendarmerie each time he finds a suitcase or a bottle on the beach.

Madagascar is right behind Reunion and will be catching most of the flotsam. Reunion is tiny in comparison and will only get a small fraction. Unfortunately, Madagascar probably doesn't have the resources to monitor its coastline. We also shouldn't get excited over finding bottles or pieces of wreckage. Islands tend to catch hundreds of tons of trash and wreckage every year. Some of it has been floating out there for decades. Finding a bottle, a handle, or a suitcase is hardly rare. It happens every day.

It seems to be mostly composite, so no scrap aluminium.

I said it in my post. A flaperon falling off in flight is rather unlikely without some sort of catastrophic outcome. It would certainly have been noticed and reported. There have been only 5 losses of a 777 (which is a rather good track record). The first 3 occured at airports and all of the parts were recovered and accounted for. The others were MH17 that was destroyed over Ukraine with wreckage dispersed over a wide area and MH370. It is rather unlikely that any parts from MH17 drifted from Ukraine to Reunion, so the wreckage can reasonably only be from MH370.

The only thing CST-100 has in common with Orion is the shape. They are completely different vehicles, with different systems, different mission profiles, designed and built by different companies. An Airbus A350 is also the same shape as a Boeing 707 even though they have nothing in common. All that means is that the shape is optimal for those engineering requirements.

CST-100 is Boeing. And it's a freaking manned spacecraft, not "just" a CST-100.

Fixed?

No, it meant French tech instead of 'Meruca!'.

Now that it's been established that this is from a Boeing 777, there have only been 5 crashes of this aircraft type: London, San Francisco, Egypt, Ukraine and MH370 in the Indian Ocean.

I was sceptical at first, but the part number (not serial number) printed on it seems to confirm that it's a flaperon from a Boeing 777. Since MH370 was the only 777 gone missing anywhere near the Indian Ocean, there isn't really much doubt.

There are three advantages of having 9 engines on each core: - Engine out capability. The Falcon 9 can make orbit with one or two engine failures. - Deep throttlability. Large rocket engines can't throttle down to 10%, so instead you only burn with 1 engine out of 9. - Economies of scale. It's cheaper to mass produce a single engine for all stages rather than two different engines for first and upper stage. - - - Updated - - - There are three advantages of having 9 engines on each core: - Engine out capability. The Falcon 9 can make orbit with one or two engine failures. - Deep throttlability. Large rocket engines can't throttle down to 10%, so instead you only burn with 1 engine out of 9. - Economies of scale. It's cheaper to mass produce a single engine for all stages rather than two different engines for first and upper stage. The OP mentions the N1 rocket, but none of the failures of the N1 were due to having a large number of engines.

In that eventuality, we would be better off stopping our population growth. There is no logical reason to keep on expanding to a population of 50 billion or more, and I'm not sure that expanding in space colonies does anything to improve quality of life. A far more clever way to sustain development is to reduce population levels to a couple of billion. Distributing contraceptives and educating women over several generations is much cheaper than setting up space colonies.

Yes, space manufacturing is one activity that has been mentioned. I don't see them building huge orbital factories though. The most likely way to benefit from microgravity manufacturing would be to use something like an unmanned DragonLab, X-37B or DreamChaser loaded with automated manufacturing equipment on board. Launch, grow crystals, return, rinse and repeat. It hasn't really been taken up by the industry though, which means that industry isn't really that interested. Would they be more interested if prices came down? Nobody really knows, but SpaceX already offers DragonLab as a commercial service and corporations aren't exactly queuing up to buy tickets yet.

Solids being cheap is a common misconception. Although the basic design is simple, designing the internal cavities of a solid booster is a complex business. The solid fuel grain has to be custom-shaped so that the combustion follows a specific burn profile depending on the launch requirements. As you can see, those grain shapes aren't exactly intuitive, and it took lots of trial and error to figure them out. This means that it was much harder to repurpose a solid booster for different missions. Both the US and Soviet space program were originally designed with repurposed ICBMs, and those early ICBMs were all liquid-based, because it gave better control of the flight profile, which meant greater precision. Later on, both nations switched to solid ICBMs, because they can be launched instantly, whereas the old liquid ICBMs required a long fueling and preparation time before being launched.

It might be useful for some industrial applications, because it has some cool (but not unique) properties, but I wouldn't consider it "vital". 250 tons per year is a tiny market in the world of commodities. Catalyst converters for the autmotive marker, which is the main industrial application of platinum, are going to be phased out as petrol/gas engines are replaced by cleaner alternatives. This will drive prices down. The appeal of platinum jewellery comes only from the rarity of it. If it was more common, you would reduce demand. As for the other applications, once you remove the volumes are anecdotal with only a few tons per year. It isn't a consumable, so it is rare and expensive enough to be worth recycling. Dump a 1000-ton asteroid on a decreasing 250-ton/year market, and you crash the price however you look at it. You can try to keep reserves and only inject small amounts on the market every year, but sitting on a pile of platinum is not going to make you rich, and it will take ages to recoup your exploitation cost. You'd be better off investing in recycling old catalystic converters. As for getting an asteroid on the ground, that would be a hugely risky business. Basically, its ability to survive reentry would depend on the structure and density of the asteroid. It might break up and explode into tiny chunks spread all over Kazakhstan, making the people of Kazakhstan rich and you very poor.

Platinum is a poor example, because the biggest market for platinum is catalyst converters for the automotive industry, which implies petrol-powered internal combustion engines. We can all agree that this market is not going to be expanding in a huge way over the next decades. The second biggest market for platinum is jewellery, for which the rarity is what creates the appeal. If platinum was common and cheap, there would be no demand for platinum jewellery. Some of it is turned into ingots and used for commodity investment. Other industrial applications are marginal in terms of volume. So if you increase the amount of platinum on the market without increasing the demand, then you crash the prices and you don't benefit from the venture. And of course, there is the cost of mining the platinum and delivering it to Earth. Again, you'll be better off extracting it from seawater or recycling it. - - - Updated - - - Yes, and building an artificial island, or floating barges covered with solar panels is still cheaper than boosting half of those solar panels to 27000 km/h and building an artificial island covered with microwave receivers.

First of all, governments are always going to find a way to tax that corporation. It will have some existence in a legal framework on Earth, presumably in a developed country with an organized government. They will be operating from facilities based in a country. If it's an off-shore company operating illegally and evading taxes, it will get shut down and won't last for long enough to recoup the investment.

So your business case is mining the Moon. The self-replicating factories and colony-cities are simply one far-fetched way of doing it. There are plenty of others, but never mind. The problem is still finding customers to buy your Moon-mined minerals. There is no demand from customers to buy Moon stuff, thus this does create an economy in space as requested by the OP. The start an economy, you need supply and demand. The technical solutions for creating supply are not the problem, which is why most people here are wrong in focusing on the those technical points. If there is demand for a product, then entrepreneurs will always find a way to purvey that product. The crucial problem is in creating demand. "Build it and they will come" seldom works in real-life.

The docking is where it goes wrong. To dock means only two possibilities: - The relative speed between the two vehicles must be zero, so either your ascent vehicle has to accelerate to the same speed as the descent vehicle, or the descent vehicle has to match the speed of the ascent vehicle. Either way, you have gained nothing in terms of energy. - The relative speed between the two vehicles is high, so the amount of energy that needs to be absorbed by the docking system is equal to the energy differential between the two vehicles, so if the ascent vehicle is near zero velocity at its apogee and the descent vehicle is at 4000m/s, then you have to absorb that energy differential without being blown to pieces. Tough.

So your huge plant is going to magically build itself from regolith for free. Sorry, but that is still science fiction. And your premise is still wrong. You consider that building a city on the Moon with self-replicating machines will generate revenue, which is not true. Building a city is an expense that is necessary to support a population. The population only comes is there is work. Which means that you still need to find the actual business plan that will generate enough wealth on the Moon to justify the expense of building a city with self-replicating machines. Why would your self replicating factory even need workers if it has an infinite supply of infinitely complex robotic systems? Building an economy is space is already hard enough. Building one where a manned presence is necessary is unrealistic.

Yep, before anyone gets to that stage, there will have to be some sort of negociation or legal process to specify the legal framework. Nobody has any interest in investing in unregulated territory because there are too many unknowns. They will put pressure on FAA, NASA or other national authorities in order to know where they stand.

Why don't you simply read the Wikipedia article on the subject? https://en.wikipedia.org/wiki/Outer_space

Relying on the stupidity of your customers is a good way to start a fad (like VG's space tourism thing), but it isn't a very sound way to build a sustainable business model.

First of all, self-replicating/Von Neumann machines are a means to reach an objective, not an objective themselves. They are not a business case themselves, but they can be used as a way to complete an actual business case. The problem is that you still need to figure out what the actual business case is. Building a self replicating factory on the Moon is not going to make anyone any money if the only goal is only to build a self-replicating factory. Secondly, self replicating machines are still science fiction at this stage. Any complex device these days is made from a variety of materials and complex components: While you can 3D-print some of the basic structural parts, it is still impractical or impossible to make things like electronic components, PCBs, solder, solvents, springs, fasteners, washers, conductors, insulants, fluids, seals, fabrics, filters, lubricants, magnets, etc... Extracting all those materials from regolith would be like building a Toyota Prius (as well as a Toyota Prius factory) by extracting the materials from seawater. It might be possible (because most of the basic elements exist in a certain amount in seawater), but it would be an immensely long, complex and inefficient process. - - - Updated - - - As for the solar power thing, it will require more energy to build and maintain an orbital power plant and the associated ground stations than to build a solar farm on Earth. If a solar array in orbit has twice the efficiency of a solar array on the ground, then why not just build a bigger solar array on the ground. There is no shortage of real-estate. It will still be 100 times cheaper than to build a half-size one that you send to orbit, plus a microwave ground station. In addition, large scale microwave energy transmission has never been demonstrated. We have no idea what the impact might be on the ionosphere, the ozone layer, or the wildlife. For all we know, it might be more catastrophic for the environment than gas or coal plants.