Nibb31

We don't have any details about how the constellation is to be set up. We don't know how many of them are redundant, how it's going to operate, how heavy each sat is going to be, or even how Musk aims to make money on a constellation that big. What we do know is that a Falcon9 launch costs $60 million. If Musk gives himself a 50% discount (which assumes his margins on a launch are unrealistically high), 200 launches is going to cost him $6 billion. Add the cost of the ground stations, the logistics of operating such a constellation, and the unit cost of each satellite, and you'll be lucky if the global investment is under $8 billion. With that investment, they are going to have to compete against 4G/LTE, broadband, cable, and other sat operators (Orbcomm, ViaSat) who already have a wide user base or other new players (OneWeb). There are still many places with poor coverage, but unfortunately, those places tend to also be poor markets, developing countries, low density areas or niche markets (ships, aircraft, etc...). As such, they are really just a niche in terms of market volume. In fact, the main reason people don't have Internet today is affordability, not access technology. The complexity of setting up a communications business (including billing, customer support, legal stuff) that covers every country in the World, including developing countries, is going to be daunting. The market is already highly competitive. Making money out of that investiment is going to be hard. So no, it can't possibly work if it requires 200 launches. My guess would be more something like 100 sats on 40 orbits at 10 launches per year.

Let's see, at 100 kg per satellite, with a payload capacity of 8 tons, that's 80 in one launch. You can launch the whole constellation in 20 Falcon 9 launches. Much less if you put them on a Falcon Heavy. So how many viable new commercial applications for space have appeared this year? Or even in the last 10 years?

I recently received an actual HDD (not an SSD) in an envelope. Of course, it was dead when it arrived.

Good luck with that business plan. I dunno... When we're talking space colonies, we're talking 22nd Century at the earliest, so I don't think it's that far fetched... - - - Updated - - - Launching a constellation is a cool contract, but those are small LEO sats. It can probably be done in a dozen launches, which is a great deal for SpaceX but hardly a sustainable increase of global launch rates. There are plenty of people imagining new applications, but until now, none of them are viable or meet an actual demand. This is only true if you have an application that requires a constellation of mass produced satellites like the one above. Note that GSO comsats are already standardized on common satellite bus platforms, common transponders, common antennas. Yet they are still expensive. They already do this. Yet comsats are still several hundreds of millions of dollars.

Sure, but we're talking about a huge investment of which launch costs will only be a tiny part; and it's still going to be a niche for a small amount of über-rich, not for the masses. Most people will still prefer to spend their week on a cruise ship or in a luxury resort on Earth for a fraction of the price. What about VR goggles in a Zero-G Airbus? Drug-induced auto-suggestion? Neuronal connections? Seriously, we have no idea what kind of VR tech will be around in 20 or 30 years. For all we know, we might be living underground in Matrix-style vats by then, and space exploration will be the least of our worries. Again, a massive investment, with or without reusable rockets. And with no identifiable return on investment, it's simply not gonna happen. Agreed. All we need is to figure out a way to make money. My suggestion: Maybe one day we'll figure out a viable use for all the stuff we've done to explore space. Until then, let's just keep on exploring and doing science in order to advance technology and our knowledge of the universe. There is no rush.

Yeah, but the average Kardashian will get bored after two hours gazing out a porthole, having ... in zero-g and drinking champaign from a straw. Your orbital hotel will have to be something epic to keep them busy, but that's not going to be cheap. The economics simply don't work out. 20 or 30 years from now, I think that are more likely to see advances in realistic VR than we are to overcome the tyranny of the rocket equation. It will be easier to relive Apollo 11 in VR or to send telepresence robots to Mars than to put space hotels in orbit. So why would they go? It's a hell of a risk to sell your house and take the wife and kids to live on Mars knowing that if your hab module springs a leak, if your generator breaks down, or if the dust gets in your food, you die. The settlement only grows if people are attracted to migrate, and that can only happen if they can hope for a better life there than on Earth. If there is a return, it's not exploration, it's exploitation. Tourism, see above. Settlement might not be in our direct future, but it's closer than having VR as an equal experience as the real thing.

This only solves the launch slot issue, which is the slightest of a company's problems if they have just lost a multi-million dollar payload. You can't launch on thursday if you haven't rebuilt a satellite by then, and of course, if the launch cost is based on high flight rates, it's unlikely that a slot will be available in the manifest. Launch services are only a small part of the operational cost of a satellite operator. The biggest costs are the satellite itself, the insurance, and the cost of operating the satellite (ground stations, personnel, services, etc...) Launch vehicle technology doesn't change the fact that space hardware is expensive. It only reduces the cost of launch, which is like reducing the cost of packaging on your latest flatscreen TV. It's a nice bonus, but not a revolution that is going to bring down the prices of flatscreen TVs by a large amount. No it doesn't. A bigger risk means a higher insurance cost. Skylon doesn't exist. We have no idea how it will operate if it ever does. A single engine failure is enough for Skylon to have a catastrophic loss. So is a TPS failure, a structural failure, an RCS failure, a landing gear failure, an avionics failure, and so many other things that are extremely more likely on a vehicle with so many unproven technologies than on a rocket. You fail to demonstrate why payload cost decreases with launch cost. The two are part of the total operational cost of a satellite (which also includes ground equipment, R&D, insurance, and operating the service over the years) The only way for satellites to be cheaper is through economies of scale and standardization, which allow mass production and higher launch rates. Again, what would be the actual business applications for mass produced satellites that could sustain high launch rates over decades? How many Earth observation or comm sats does a company need? If a higher flight rate does not get utilized, then it's not a higher flight rate. Launch services are tailored for a market that exists. If you setup your launch service for a market that doesn't exist, then you are losing money. There is no inherent reason for a higher flight rate to be safer than a lower one. If anything, it is the opposite. If the reason that the satellite costs $500 million is because it's 5 times more reliable and hardened than a $100 million satellite, then operators will go for one reliable $500 million sat rather than two $100 million sats. Insurance companies will also offer better rates on the more reliable one than on the cheaper ones, which reduces your operational cost.

Technology has its limits. If you lower the price of a seat to orbit to $1 million (which is a crazy low price that beats even the most optimistic previsions), it will still be for a handful of rich people. Even at $100000, it would still be a once in a lifetime joyride for rich people, not a mass transport thing because orbit isn't a destination where people want or need to go. And by the time we get to those prices, there will probably be high-definition VR that will get you the exact same experience without the price tag and space sickness. That actually goes against more frequent flight rates. Why would the average Joe want to settle on Mars or the Moon with his family? Humans migrate to where the grass is greener, to improve their comfort or safety and those of their children. They don't choose to spend the rest of their life in a trailer with artificial life support in the middle a barren desert. How would moving to Mars improve their quality of life or provide better prospects for their children? Exploration is a very low volume and is limited by the face that it's a government activity. Commercial exploration isn't much of a thing. Comsats provides the bulk of the market, but it's competing with land lines and wireless and becoming more and more niche. Most people these days are switching from GSO satellite TV to IPTV over DSL or optical fiber. 4G networks are still cheaper to maintain that comsats. Tourism, well see above. Settlement is science fiction with zero basis in reality.

There was demand for transportation before airlines or cars existed. Since the Roman Empire, there has always been a necessity to move goods and people from A to B, because there were people that lived at A that needed to meet other people that lived at B or they wanted to sell products from A to people in B. Ships, trains and airplanes didn't create the demand for transportation. Those technologies were developed and adapted to fulfill a demand that existed. The same is true for rockets. The problem with orbital launches is that LEO isn't a very appealing destination other that for some very specialized applications. People aren't queuing up in millions to go to space like they want to go to London, Tokyo, or New York, because there isn't anything for them to do in space. There are no business meetings, no relatives to visit, no museums or theme parks, no wildlife or landmarks to visit... Going to orbit is nothing more than a joyride, and a joyride doesn't justify the cost.

The most annoying thing when Hollywood portrays foreign characters is that they get a corny accent, but use perfect English grammar, colloquialisms and idiomatic expressions, while still using words like "bonjour" or "fraulein" whenever they can. Tip for screenwriters: foreigners usually know how to say "good morning" or "thank you", but they are more likely to get their grammar wrong and won't use expressions like "driving me up the wall" or "pulling your leg".

Progress and improvement are subjective. Who says that a reusable space shuttle is an improvement? If the goal is economy and efficiency, then there are several ways of reaching it. It doesn't necessarily have to be through one technological path.

Ikea (and pretty much every company in the world) probably spends millions to convert their catalog to imperial just for the US market. The current situation of using special units for a single country probably costs more over a decade than an overnight conversion would. The entire Euro zone (300 million people) converted from their local currencies to the Euro. Several countries converted from left-hand driving to right-hand driving overnight without too much trouble. Canada and Australia converted to metric in the 70s with no huge adverse effects. It really isn't that hard.

The meter was originally based on one ten-millionth of the length of the earth's meridian along a quadrant. The great The rest of the metric derives from the meter, which makes conversions easy: - A metric ton is the weight on one cubic meter of water. - A liter is the volume of one kilogram of water. - 0 to 100°C is the scale of water freezing to water boiling. - Newtons, pascals, joules, sieverts, etc... are all derived from those basic physical measurement. The strength of the metric system isn't so much in the conversion between grams and kilograms and meters and kilometers. It's also so much easier to convert weights into liquid volumes (which is actually damn useful for cooking or baking cakes) or to convert newtons into joules or to calculate pressures, speeds or other values. And yes, people from outside America can eyeball meters as easily as an American can eyeball yards or feet. As a person used to the metric system, I personally can't make any sense of a person's heights expressed in feet and inches or temperatures in fahrenheit. I can more easily visualize a hectare as a square of 100x100 meters (or as 100 10x10 meter squares) than an acre in feet or yards or miles.

If we are to believe "most sources": - Become a person with zero credibility (get drunk, take drugs, have mental problems, be a child under 10) - Drive through the desert in pickup truck playing country music and drinking beer - Alternatively, be all alone on an isolated farm in the middle of nowhere - Be American (UFOs are only interested in the USA) - Don't have a cell phone or recording device

Demand isn't created only by cost. Just because something becomes cheap doesn't mean that everybody wants it. Even if launch costs were cut by 50% (which isn't realistic in any of the current reusable launcher proposals), a launch will still cost 30 to 50 million dollars. Payloads will still cost several times that amount and new reasons to go to space are not going to appear out of thin air. What you need is new applications for spaceflight that make sense economically. Unfortunately, none of the futuristic ones (space manufacturing, asteroid mining, orbital tourism, etc...) are viable or propose an attractive business model, even with a large discount on launch prices.

But government funds are limited and won't increase demand by a level of magnitude. You need private commercial applications for that.

They could be caused by meteorites that disintegrate into many smaller parts and crash while the planet rotates. Maybe a phenomenon similar to the Shoemaker-Levy 9 observations could cause something like this.

If you throw a party once a year with 100 guests, it makes sense to buy disposable cups and plates. If you open a restaurant with 100 guests every night, it makes sense to invest in reusable glasses and plates. Reusable rockets only make sense if you have high launch rates, which means increased demand for orbital flights. You don't increase demand by only cutting prices. There also needs to be a reason for people to want to send stuff to space, which means actual applications and business models built around them. The technology isn't the limiting factor here. The economics are. If demand appears for reusable rockets, then the industry will figure out ways to make rockets reusable. It's just that until now, the economics of spaceflight are balanced in favor of disposable hardware, just like the fast food market is balanced in favor of disposable cups. This might change in the future if someone finds a business model that requires frequent orbital launches. For the moment, there is no such business model because the only applications for orbital flight are defense, research and comsats.

No they're not. SSTOs have a tiny payload fraction. If you want to recover your SSTO, then you need to add a TPS and recovery hardware (wheels, wings, parachutes, fuel, etc...) for the entire rocket which turns your tiny payload fraction into a negative payload fraction. Multiple stages allow a more significant payload fraction, which provides a margin for the smaller TPS and recovery hardware for each stage.

Actually, the article claims 80% of the launcher cost (which is grossly exagerated). It's possible that the engine and avionics might represent 80% of the core stage, but not the cost of the launcher nor the cost of the launch operation. Tankage is cheap in comparison. It's basically just reinforced sheet metal, and as SpaceX has learned on its latest landing attempts, getting and empty tank back in one piece complicates things a lot by making the recovered section heavier and more instable. It's much easier to dump the tank and concentrate on the expensive parts. The difference between restacking a reusable core stage with an upper stage and a reusable engine pod with a tank and upper stage is marginal, so it won't make that much difference in terms of ground ops. The biggest activity in that area will always be payload integration, where reusability doesn't make any difference. The difference is the flight rate. Airliners are an answer to demand for mass transport. There is no demand for mass transport to orbit and back. Orbital launches are a niche activity with different economics. The payloads are more valuable that the launcher. For the satellite operators, the launcher is like disposable packaging. Launch providers can save money by reducing launch costs, but those savings are marginal compared to the total operation cost for the customers.

It wouldn't be nearly as bad or as sudden as you say. Geostationary sats are all travelling at the same speed with attitude control and station-keeping. First of all, space is mindboggingly big. GSO is at an altitude of 36000km, which makes the entire perimeter of the orbit 36000+12000+36000*pi = 264000 km. That is a hell of a long line to string 400 satellites: one satellite every 660 km. Some areas are more crowded than others, but the closest distance between two GSO sats is about 70 km. To intercept another satellite, any debris would have to be going either faster or slower than a geostationary sat, which means that it would flying either above or below geostationary orbit. It would only intersect the geostationary altitude twice on each orbit, and you would have to be extremely unlucky if those two intersections happened to be on the same inclination AND and on to collide with another sat when the average distance between two sats is the size of Germany. Your odds of debris killing off every GSO satellite are infinitesimal.

Russia has pretty l much given up on space planes, unless you know something we don't. No it wasn't, as has been mentioned several times in this thread. It was destroyed by the collapse of the roof of the assembly building in which it was stored.

The pictures that I posted seem to show the subscale models flying, so the design seems to be airworthy...

You are pulling numbers out of your backside again.

There do seem to be some pictures of flying prototypes and mockups: