Nibb31

Yes, reusing boosters will save some money. How much, nobody knows, and that is why the entire industry is in "wait and see" mode, watching SpaceX very closely. Nobody doubts they can do it technically, but can they do it economically? Do not assume that the largest cost factor in operating a launch service is manufacturing the first stage. It isn't. The largest cost is the manpower that operates the launch service, and SpaceX is already about as cheap as it can be on that side (unless they start outsourcing to India, which I doubt). Even with reuse, they will still have to maintain that huge factory in Hawthorne (which is actually scaled for mass production, not reuse). Producing less Merlins and stages means that the unit cost of each Merlin and stage increases dramatically. And even if launch services cost 10% less than it does now, that is a tiny drop in the total cost of operating a satellite for the end customers, so it won't be a huge stimulus that will create an overwhelming demand. Launch offerings have never been the bottleneck for the space industry. The barriers to reusability aren't technical, they are economical. The reason NASA or the historical aerospace industry haven't done isn't because they are stupid. It's because it has never got past the trade study review phase. With low launch rates, it isn't worth the effort. When the need for high launch rates and fast turnaround appears, then reusability will happen naturally, with or without SpaceX.

CMGs are typically among the most common failure points of these missions because they have constantly moving parts and lubricants along with thermal and weight requirements. It's not easy to design stuff that works in space.

Except the X-37B is unmanned, and the USAF actually has a use for it. It was unworkable in the early 1960's. They didn't have the TPS material (it would have likely had an expendable ablative TPS like the X-15). It probably wouldn't have been controllable on reentry. They didn't even have fly-by-wire in those days. In the end, there was no real use for DynaSoar that couldn't be fulfilled with a much simpler design. But I agree that if DynaSoar had been done, they would probably have given up on spaceplanes much earlier and we would have been flying proper capsules through the 80's and 90's.

To be fair, the STS was a much more complex machine that the F9 first stage. Those SSMEs were beasts of complexity. The F9 is much smaller, much simpler, has no TPS, no payload connections, no doors, no life support, no coolant loops, no fuel cells, no tires, a much simpler hydraulic system, simpler avionics, etc... Each Merlin engine is already test-fired dozens of times before launch without being taken apart and refurbished. There is no reason to believe that they can't technically reuse boosters. On the other hand, the logistics, infrastructure, stacking, payload integration, testing, ground personnel, overhead, etc... all remain the same. There are no real gains there. It takes weeks to prepare a rocket for launch, and I don't see why reusability will make that any faster. The only saving is the manufacturing cost of the first stage, which probably isn't that high to begin with, because SpaceX is a pretty lean machine when it comes to production. Where I have my doubts is in the economics of it. Launch rates aren't high enough to justify it, and the small cost reductions for SpaceX won't necessarily translate to cost reduction for customers. Remember that launch cost is just a tiny part of the total cost of operating a satellite for the end customer. Manufacturing of the first stage is just a tiny part of the launch cost. And the launch cost is not the launch price. SpaceX has no incentive to cut prices by 10% more when they are already 50% cheaper than their competition and they already have a huge backlog. In fact, it would be a stupid move.

I agree, buying batteries with the car is also going to be a major risk when the second hand EV starts developing.

Probably for the subscale suborbital model. It seems to be similar to the IXV test that launched on Vega.

Not really. It was just a winged capsule that weighed much more than a conventional capsule. As a result, it launched on top of an expendable rocket that was much larger than it needed to be. It also had no actual operational capability (like docking, crew transfer, EVA, etc...).

Actually, a lot of Ariane 5's avionics was recycled from Ariane 4, which was the main cause of the failure that occured on Ariane 5's maiden flight. The electronics are a tiny part of the cost of the rocket. Aerospace-grade flight computers are pretty standard and don't need to be extremely powerful, but they need to be certified, and so does the software. The cost of hardware and software certification is typically higher than the cost reduction that you get by using more modern hardware. In other words, it costs more to certify new hardware, to write new code, and to certify that code, than to use 30 year-old computer technology.

The Moon is 3 days away with launch windows just about anytime if you use a parking orbit. Let's demonstrate that we can actually go and live on the surface of low-gravity near-vacuum body, develop ISRU and closed-loop ECLSS with the backup ability to send supplies if necessary and abort at anytime and a cost of access that we might actually be able to afford. We have SLS, Orion. All we need to develop is a lander and surface hardware. Sure some of the hardware design will be different for Mars or Venus, but the actual procedures and ECLSS will be very similar. Hardware design isn't nearly the hardest piece of the puzzle. The hard part is organisation, budget, political and economical sustainability, procedures, infrastructure. Mars or Venus are simply out of reach in terms of economics and politics, and that is not going to change any time soon.

Beautiful ! Congratulations SpaceX !

It will be a scheduled deorbit with a series of burns from a visiting vehicle, most likely a Progress. They will make sure it comes down in a remote area. Seriously? Have you even read the thread before posting in it?

Let's see. Unflown derivatives of actual spacecraft: Gemini: Blue Gemini, Big Gemini Saturn V: Saturn N, Nova, Wet Workshop Apollo: The entire AAP program (LM Truck, LM Shelter, MOLAB, ATM...) Soyuz: LOK, Military Soyuz, etc... Check out www.astronautix.com. The whole website is dedicated to the more obscure sides of both the US and Russian space programs.

That sort of price is pure fantasy, with or without reusability. Not realistic either. Cost of a launch <> Cost of launch vehicle. The biggest part in the launch cost is the workforce. The actual hardware is only a minor part of the total launch cost, and the manufacturing cost of the first stage is only a part of the total hardware cost. There is also infrastructure, logistics, testing, payload integration, and all sorts of administrative overhead. Reusing first stages does little to reduce the workforces or any of those other costs, and SpaceX has already managed to price themselves 50% cheaper than their competition, so expecting reusability to further decrease launch prices by more that 10% is wildly optimistic.

1) I doubt reusability alone will bring prices down by an extra 30%. Even if it does save them some money in the end (which isn't a given), SpaceX is already the cheapest shop in town. Why would they want to cut prices even more, especially if they are trying to raise money to develop Musk's Mars plans. 2) Arianespace needs to reduce their prices too. However, I fail to see how Ariane 6 can actually be that much cheaper. It reuses most of the technology from Ariane 5, including the Vulcain and the upper stage, but also needs a lot of new development and a new launch pad.

Not when you're in a hurry it doesn't. Sitting around for two hours waiting for your battery to charge isn't very practical. As for fast charging, I'm pretty sure that it reduces the lifetime of the batteries by a serious amount, which is bad for the environment (batteries aren't exactly clean to make). For the same reason, I charge my phone all night on a old 0.5A charger rather than on the 2A "fast charger" that was supplied with it and is supposed to charge the battery in 1 hour. My battery is now 3 years old and it's still running strong.

What if FTL simply isn't possible, which rules out interstellar travel by making it so impractical that it is not worth the effort. Another option is the Dark Forest hypothesis: There is a 50/50 chance that another species is hostile and wants to wipe you out, so it's best to keep quiet. Or there might be a predator species out there that considers any other species a threat and destroys them preemptively just in case. They might even have some form of time travel, so they can go back and destroy others before they are even capable of making contact.

I have googled stuff that I contributed online back in 1995. Yep, I've been on the Internet for over 20 years. Back in the days, I used gopher, ftp, email, and usenet on a old Data General terminal. I remember browsing the web with Lynx through a telnet connection. And then came NCSA Mosaic... I remember writing web sites in HTML and FTPing them to Geocities. For those interested in history, I suggest using the the Internet Archive's Wayback Machine: https://archive.org/web/ For example, this was NASA's first web site. This was IBM's first web site. This was Google.

I'd also say walking is more efficient. Walking is a kind of "controlled fall". Much of the work is helped by gravity and inertia.

Let's rename Spaceception because I don't like his name. Let's all call him Albert now.

The boosters seem to be reusable, but they carry a heavy mass penalty for no good reason. The core doesn't seem to be reusable. What's the point?

That market wouldn't exist if there hadn't been a government-funded launch industry. Sure it might have happened one day, but it wouldn't be very competitive.

How would we know that we needed resources from space if there was no space program in the first place? Who would invest billions of dollars to start a private space program out of the blue without a proper business model? There isn't any need for resources from space, so you're just arguing for science fiction. You're not making any sense.

But we don't. So they wouldn't. And even if we did, we wouldn't have any idea about the composition of the Moon or the asteroids if governments didn't fund space science. This discussion is going nowhere.

They would not be operating in the space industry because there would be no space industry without NASA and DoD. No. Let me make this clear. The private sector would only invest in space exploration if there was a potential for a return on that investment. Currently the only possible reward for developing space technology is to sell that technology to NASA or the DoD. Without government money, there would be no possible return on investment for the space industry. None of that is secret. There are hundreds of experts and analysts and consultancy agencies whose job is to look at the professional market, the industry, geopolitical data and to provide insights for all sorts of decision-makers. These people produce reports and trade studies for the space industry or publish papers in professional journals. Trust me, there is nothing that Musk knows that the rest of the industry doesn't.

That would be basically a whole new spacecraft design (including engines, avionics, power, attitude control, docking system) that you would have to send up empty for the sole purpose of handling garbage. Not worth the cost. Batteries, consumables, coolants, solar panels, seals, gaskets, filters, insulation, etc... Any part that is certified for a specific on-orbit life or a specific number of thermal/mechanical cycles. Visiting vehicles are designed to be expendable. Making them permanent would require redesigning them, which would increase their cost. And then you would run out of docking ports for the next vehicles and you would be swamped with trash. That would take up weight and room that is dedicated to cargo. Then you would have to outfit the inside to give it any use. Not really. More space means more load on the ECLSS. The CBM is the current large berthing system. The new system is LIDS, NDS, IDSS, IDA (it changes its name every couple of years), which is smaller and designed for the new crop of visiting vehicles. I doubt it will be cheaper. Note that Dragon plans to reuse the its docking adapter, whereas the other vehicles jettison it for reentry.