Nibb31

Conceptual study only. None of that technology is going into Ariane. Flyback boosters are not a new idea. There have been dozens of studies like that, including Energia, Baikal (Angara) and Lockheed Martin. There have been concepts designed for the Shuttle and even for SLS. The idea is for them to glide back to a runway, but nobody has done it yet.

Again, this isn't necessarily true. It's got to a point where the performance is similar and the extra torque gives an advantage. A couple of examples: BMW 320i (petrol): 0-100km/h in 7.3 seconds - 80-120km/h in 7.4 seconds - top speed: 235km/h - torque@rpm: 270@1250-4500 BMW 320d (diesel): 0-100km/h in 7.4 seconds - 80-120km/h in 5.9 seconds - top speed: 235km/h - torque Nm@rpm: 380@1750-2750 Renault Mégane TCe 130 (petrol): 0-100km/h in 10.7 seconds - top speed: 200km/h - torque Nm: 205 Renault Mégane DCi 130 (petrol): 0-100km/h in 9.8 seconds - top speed: 200km/h - torque Nm: 320 And of course, fuel efficiency of the diesel engines is much better. In the European market, the petrol engined versions are strictly for the entry-level models because of the cheap price point, but in the mid-range and above the diesel models sell more.

Actually, if you fly around the Kiribati Islands, you can even cross the dateline several times. Good luck in knowing what time or even day it is when landing at a random island in that area!

It also depends on where you're doing the job. In Europe, at least 50% of cars are diesel powered because the taxes are typically much lower. In some countries, it goes up to 70%. If you are buying a family car or anything bigger than a Renault Clio, you'll have trouble finding one with a petrol engine (except in sports cars and some niches of the market). This doesn't mean they are sluggish. Because they are so widespread, there has been a lot more R&D done on diesel engines in Europe than in petrol engines. Modern diesel engines are nifty, and the torque translates directly into acceleration. The torque also allows manufacturers to fit smaller engines. My last car was a Renault Megane Estate, with a puny 80hp dCI engine. It sounds underpowered, and indeed an 80hp petrol engine would be, but with a modern diesel it had rather impressive performance for its size and consumption. It did less than 5l/100km on average, which is really good. Diesel fuel is now getting much closer to the price of petrol, but you still get better mileage out of it. But at this stage, electric vehicles are starting to look better. They have better acceleration than any internal combustion engine and are starting to be perfectly adequate for the daily commute. I have several coworkers who use them on a daily basis and they're really happy with them.

Ever heard of the international date line ? There are places in Alaska where you can actually see tomorrow from your doorstep

You couldn't launch 3 Falcon Heavies in short enough timeframe that would prevent boiloff of the upper stage propellant. FH can only launch from KSC Pad 37B. But most importantly, that sort of mission profile would require a huge investment in time and money to develop the hardware, which would push the project beyond the launch window and way beyond the budget. There is no autonomous docking-capable interplanetary upper stage. There is no hab module compatible with Dragon. There is no reliable 2-year life-support system. Heck, simply developing a toilet for Dragon would cost more than the entire budget for this project.

The late Altair lander design (the first picture) looked seriously cramped to me. Is don't see how they could have spent 2 weeks with 4 people inside that tiny cabin. Plus, a lot of that space was supposed to hold an airlock. The original Constellation (the second picture) always looked better.

The difference being that the rest of the world was habitable without constant supply lines and fragile high-tech life-support.

Looks like a nice machine. I have a soft spot for Lenovo, and it's the brand that NASA uses to fly on the ISS For your hard drives, you can get a cheap SATA=>USB cable for the transfer, or you can buy an external USB enclosure so that you can recycle your old drive for backups and stuff. But if your old computer still works, you can just copy the files over the network.

You have just insulted the thousands of engineers and scientists that work in the aerospace industry. Contrary to what some people here think, they are not idiots, they are not conspiring or lobbying for big aerospace companies. Space is their bread and butter. They know what works and what doesn't. If there really was an easy way to accelerate stuff from 0 to 27000kph, they would have figured it out by now. Well, nothing exists in a vacuum. To make a project work, especially big ones, you need a whole array of skills. This includes engineering skills but also business skills and political skills, because that's the kind of world we live in, whether you like it or not. Some things might be technically possible, the engineers will push in one direction, the marketing folks will push in another direction, and you usually get the lawyers, the upper management, and the bean counters all pulling in their own directions. For a project to come together in real-world context, you need everyone to reach a common ground. You can't wave away the parameters that you don't care about. Sounds like an obsessive-compulsive behavior if you ask me, but well... There are no exploration missions that were cancelled for the lack of heavy launchers. Again, exploration missions depend on the science budgets of space agencies and universities. The bottleneck is the money, not the launcher.

The Russians assembled Mir in less than 10 launches. It took the STS 27 missions to complete the US segment of the ISS. The STS could put 100 tons into orbit, but only 20 tons of payload because the other 80 tons had to come back. The old Saturn V could also put 100 tons into orbit, so it could have launched the entire mass of the ISS in 5 only missions. If Hubble had been designed without the extra hardware required for manual maintenance, it would have been much cheaper and could have been replaced with 2 or 3 copies for a fraction of the cost of the manned maintenance missions. The Shuttle was great idea that was worth trying. We learned a lot from its mistakes.

In any case, I hope nobody is going to pay $1 million for the view. A Mars flyby will always approach and leave the planet on the dark side, so you won't see anything. Other than that, it's ludicrous to think that this could be done in a Dragon, or that you could develop and test a 2-year life-support module for that amount of money.

Is your KSP Falcon modeled to the exact same weight ratios and engine performance as in real life? Does it get damaged by reentry heat? Are you flying your payloads to GTO or high inclination orbits? If you reduce the cost by 20%, which is what reusing the first stage of a Falcon 9 might achieve optimistically, then the price goes from 60 to 50 million dollars. That is not going to spawn new markets. The launch cost is typically less that 25% of a satellite project. The satellite itself is approximately 50%. The rest is ground systems and operations. So the saving for the customer is 20% of 25%. That's nice for the operator's bottom line, but it's not revolutionary. Nope, it doesn't work that way. Take 10% off the price of a $1 million dollar supercar, and you're not going to sell 10% more cars just because they are now $900.000. (In this particular case, you might even sell less.) Even if you reduce the launch cost from $60 to $6 million (which is completely unrealistic), you are not going to launch 10 times more satellites, because the market is not expandable that way. SpaceX is a great illustration actually. In 2014, their launch prices are practically 50% lower than the competition, which is a great achievement. The only effect is that it is drawing existing customers from the traditional launch providers, but it isn't doubling the number of launches per year. There are a couple of projects of constellations for broadband orbital internet, with hundreds of small satellites, but those will be launched in clusters, so the actual number of launchesmight be around 10 or 20, which isn't that huge. It will keep launch providers busy for a few years, but it's not a game changer.

Talking about modules such as Zarya or Zvezda (or the Mir and Soyuz equivalent). No capsules, 700m/s of dV on their own.

Most elements could be extracted from sea water for a fraction of the cost of asteroid mining. Platinum is around $40000 per kg, so a ton, at current prices, is "only" $40 million. That's not even enough to launch a Falcon 9. The propellant to bring it back to Earth would outweigh that cost, and so would the cost of sending up the machinery that you would need to extract that ton of platinum. And you also have to consider that dumping several tons of platinum on the market will crash the price, making it even less worth while. The mass market for platinum is the industry, mainly for catalytic converters for gas-powered engines, which will be phased out over the next couple of decades. There will be other industrial uses, but the main reason platinum is expensive is because it's rare. Remove the rarity, and down goes your profitability. If there ever is asteroid mining, it will be fully automated or teleoperated. Adding humans into the equation increases the cost by orders of magnitude.

Well, the Salyut stations at least had their own propulsion. The TKS or DOS vehicles are fully-fledged spacecraft with as much dV as a Soyuz or a Progress, since they reach their targets, rendezvous, and dock under their own power. Where do you put the limit ?

Yes, and those savings have already been applied. SpaceX is about as lean as it can be, which makes trimming more overhead off even harder.

Not the smallest, and nobody has the exact numbers, but an educated guess suggests that the actual manufacturing process of the first stage isn't the most expensive part of launching a rocket. The biggest cost factor is probably the R&D. And even in the manufacturing process, the largest cost factor isn't the raw materials to build the rocket, it's the workers. By reusing rockets, you need less of them, but you still need to maintain a factory and a decent workforce to run it, so you don't necessarily make huge savings there. And the manufacturing workers are only a small part of your total workforce. The highest salaries are in the R&D and mission control departments. And you are still going to need hundreds of people to do all the logistics, transportation, payload integration, testing, and other administrative work. There is also the cost of maintaining facilities. Launch sites, research centers, factories, mission control centers, aren't cheap. So, even if the actual hardware is 50% of the total launch cost, the first stage is probably around 70% of that, which would make it 35% of the total launch cost (not the price!). The price of a launch, is $60 million, so to simplify, let's consider that the cost without reusability is around $50 million, so you save $17 million on each reusable launch. If you reuse your first stage 10 times, it brings the average cost of a launch down to around $36.5 million ((1x50+9x33)/10), which results in saving about 30%. But that is a highly optimistic estimation. It assumes zero refurb cost, zero transport, and a constant unit price for the actual reusable unit. It also assumes 10 time reuse, which is also optimistic. Don't forget that the cost of each unit increases as you reduce the number of units produced. If a factory is sized to produce 400 engines/year and you only build 40, then your costs are not optimized. Your fixed costs take a larger part of your total costs and ou also don't get large volume discounts from your suppliers. So your unit cost increases, which also eats into the savings that you might get compared to launching 400 disposable engines. There is a balance to be found somewhere, and until SpaceX has some real data about the recovery and refurbishing costs in an operational environment, nobody really knows how much reusability will save. So it's more likely that in the end, you're looking at something like the 20% figure I quoted above. Conveniently, when applied to the public launch price, it brings the $60 million figure down to $50 million, which is what SpaceX was charging last year.

Erm... and the ISS, and Skylab, and Salyut, Mir, etc... There are a whole bunch of spacecraft that don't have atmospheric flight in any part of their nominal flight profile.

Reusing only saves the manufacturing cost of the stage, which is only a small part of the total launch cost. All the other costs associated to operating a launch service and maintaining the infrastructure and R&D remain. You still have to pay for the R&D, logistics, integration, facilities, mission control, marketing, and administrative overhead. As long as SpaceX hasn't done several cycles of actual reuse, we can't really have any idea of the actual operational costs. A wildly optimistic estimate is that reusing the first stage of the Falcon 9 might save 20% on the total cost. That could bring the price of a F9 launch down from $60 million to $50 million. On the Falcon Heavy, reusing a single core as planned, would save you much less than that. Reusing all three cores might save you a little bit more. But as has already been noted, reuse of the central core isn't realistic at this stage, and it might not be possible to recover both of the side cores. Also note that the Falcon Heavy has the same problem as SLS: the lack of payloads. There aren't any 50 ton payloads in the pipe, so there is no market for it. Science institutions don't have the budgets to design large missions like that and the commercial comsat market uses standardized satellite platforms that are smaller but launcher-agnostic, which is a major cost-saver. Developing a larger commercial satellite bus that is tied to a single launcher brings some additional cost and additional risk that comsat operators might not be willing to take. The capacity of the Falcon Heavy is a bit of a game changer that requires customers to change their game too, and we aren't seeing any of that emerging.

What science fiction spaceships are you talking about?

A few thousand people ready to shell out $100 doesn't make a market. When the costs are in the billions of dollars, you're going to need a market in the billions of dollars. Get several thousand people queuing up to pay $1 million, and then we can start talking. It will be a long time before prices get down to a $1 million ticket for a few days in LEO, let alone for a 2-year trip to Mars and back. - - - Updated - - - Not a hoax, but when your business model is about spinning PR just to get the money feed the CEO for a few years, then it's pretty much a scam. Even if it isn't a scam, it's vaporware.

What exactly do you call suborbital? If I jump up and down, I'm technically doing a suborbital jump. Model rockets are suborbital. If it's just to send a small science payload beyong the Karmann line, Von Braun could do it with an old V2, or you can use cheap solids, or even a small ASAT launched from an F-15. Morpheus would be overengineered for that sort of thing because it was a *landing* research platform, not a *launch* research platform. The emphasis was on deep-throttling and ISRU-ready propellant and vacuum Isp. If you were to build a suborbital *launch* vehicle based on Morpheus' engine technology, then it wouldn't be Morpheus because it wouldn't need those things. You would basically and optimize it for atmospheric flight Isp, thrust, and easily-available propellant, which would make it a very different rocket.

Amazon wasn't funded by the government. Falcon 1 was developed by SpaceX with Musk's money, but built around an engine that was designed by NASA. Falcon 9 and Dragon were developed and designed with a large part of NASA funding through the CRS and CCDev programs. The progression of SpaceX has been impressive, but it was only possible because of NASA's subsidies and support. Companies like Amazon or Tesla (or IBM, or Apple, or Ford, or Bell) were pioneers, but before they even started, there was a potential untapped market that was waiting for easy online shopping, affordable EVs (or enterprise computing, accessible GUIs, mass-produced cars, or a telephone service). They were visionaries because they had detected the demand for their products before the competitors. They didn't create the demand, it was already latent. If Musk ever goes to Mars, it will only be because someone pays him to take them there. SpaceX will provide the transport, but they still need customers who want to go there and it will always be an expensive ticket. But there is no market, no latent demand. The only entity that has an incentive is the public sector for research and exploration purposes. There are no private customers.

Who else has the money and the incentive ?