SpaceX Super Rocket?

[asmi]

And again, a one launch monobloc station would look nothing like the ISS, it would be designed in a completely different way, but please go do your research on the Skylab station to see what was possible with a SINGLE Saturn V launch nearly 40 years ago ! Even today, it's pretty damn impressive

Interesting fact, after dozens of launches to build it, ISS has around 15,000 cubic feet of habitable volume, Skylab had 11,290 cubic feet of habitable volume from a single launch !

J

What is so impressive about Skylab? Remember we don't put stations into orbit for the sake of putting station into orbit, but to do research there. Skylab was very primitive in that regard.

And imagine for a second what would've happens should that launch fail? Ooops, no mission. While for ISS it would merely constrain the mission somewhat until replacement is built and orbited.

[Simon Ross]

ISS has 29,600 cubic feet of pressurized volume to Skylab's 11,290. More impressively, it masses 450,000kg to Skylab's 77,000kg, which is the really relevant metric.

Please please, please check your facts !

Yes, ISS has 30,00+ cubic feet of pressurised volume, however, only 15,000 cubic feet is actually habitable ! http://www.nasa.gov/mission_pages/station/main/onthestation/facts_and_figures.html. Skylab had an actual 11,000+ cubic feet of HABITABLE living space http://www.space.com/21055-skylab-space-station-nasa-infographic.html

How is mass a relevant metric ? To me it's quite a damning statistic, all that money, all those launches all that mass and we have barely got more living space in LEO then a single launch accomplished 40 years ago !

That's the downside of modular construction, a large part of your payload capability and space gets wasted due to the large number of interfaces you need to incorporate into the design. Engineers don't like interfaces !

Edited February 18, 2014 by Simon Ross

[Simon Ross]

What is so impressive about Skylab? Remember we don't put stations into orbit for the sake of putting station into orbit, but to do research there. Skylab was very primitive in that regard.

And imagine for a second what would've happens should that launch fail? Ooops, no mission. While for ISS it would merely constrain the mission somewhat until replacement is built and orbited.

In truth, if I had a day spare to go into detail on how impressive Skylab was (and still is) I would. However I will simply refer you to probably the best book written on the subject http://www.amazon.com/house-space-Henry-S-F-Cooper/dp/0030166861 as it explains it much better then I ever possibly could

[Red Iron Crown]

Please please, please check your facts !

Yes, ISS has 30,00+ cubic feet of pressurised volume, however, only 15,000 cubic feet is actually habitable ! http://www.nasa.gov/mission_pages/station/main/onthestation/facts_and_figures.html. Skylab had an actual 11,000+ cubic feet of HABITABLE living space

How is mass a relevant metric ? To me it's quite a damning statistic, all that money, all those launches and we have barely got more living space in LEO then a single launch accomplished 40 years ago !

That's the downside of modular construction, a large part of your payload capability gets wasted due to the large number of interfaces you need to incorporate into the design. Engineers don't like interfaces !

Mass is the relevant metric because it's what makes something difficult to get into orbit. Volume doesn't appear in the rocket equation.

You're also assuming that habitable space is the end goal of a space station, and maybe that's so. But Skylab was more of a spacecraft than a true station. It was not meant for permanent occupation, resupply was far more difficult than with ISS, and it had a very short lifetime in comparison. Of course a larger proportion of ISS' volume is dedicated to the support systems, supplies and experiments that make the station viable.

Those interfaces that you dislike are what makes modular stations so flexible. You can dock many craft or modules simultaneously. You can change the design of the station as lessons are learned from early modules. You can reuse modules from old stations in new ones, as the Russians are planning to do with ISS modules for OPSEK. You can seal off damaged modules from the rest of the station, as happened aboard Mir.

I don't mean to slag on Skylab here, it was a marvelous accomplishment for its time, and pioneered many of the technologies used in later endeavors. But modular design is the present and future of space stations.

Edited February 18, 2014 by Red Iron Crown

[Kryten]

And imagine for a second what would've happens should that launch fail? Ooops, no mission. While for ISS it would merely constrain the mission somewhat until replacement is built and orbited.

This, especially given just how close Skylab came to being a complete failure. It shows a major issue with the idea of building large boosters for space exploration; there's no other reasonable payload except stuff like monolithic space stations, so any failure is going to destroy something extremely expensive, and there's much less opportunity for reduction of both cost and risk.

[crazyewok]

So, crazyewok, knowing that every time it launched, 12 people would certainly die, would you be willing to be the one giving the launch command?

As I said I think it was recalculated to less than one after some rework.

And yes. Car transport has killed more.

[Kryten]

As I said I think it was recalculated to less than one after some rework.

Could you please go and yammer on about your Orion obsession elsewhere? We don't need yet another thread derailed, particularly one in which it's completely irrelevant.

[hugix]

It all depends on what type of mission you are launching. Except for a few missions a year all launches are unmanned. And the funny thing with probes is that they tend to get smaller and more expendable. (Moore's law). I am a huge fan of cubesats. It gives small nations / university students access to space.

They main reason there is no super rocket is because there isn't much market for it. Most of the payloads are getting smaller. Except for a few manned / interplanetary missions. Most payloads shrink. And why built bigger rockets for smaller payloads? The idea of a space station is actually quite outdated. There are few tasks that robots can't do that humans can that are essential in space. In that perspective more living space is actually a nagative factor. Since you waste more mass on living space that could have been used by experiments.

[Albert VDS]

I don't mean to slag on Skylab here, it was a marvelous accomplishment for its time, and pioneered many of the technologies used in later endeavors. But modular design is the present and future of space stations.

Let's put it this way then; A Saturn could put the ISS up in 7 launches compared to the 30+ launches it actually took.

That's a whole lot of time saved to actually start using it.

[Red Iron Crown]

Let's put it this way then; A Saturn could put the ISS up in 7 launches compared to the 30+ launches it actually took.

That's a whole lot of time saved to actually start using it.

Is it? I don't think the limiting factor was launcher availability. The modules weren't sitting in a warehouse awaiting the next shuttle vacancy, the design and construction of modules was an ongoing process. As was securing funding, which is another factor against monolithic station design. If all of ISS' cost had to fit in one budget year, it would never have gotten of the ground. Only by breaking it up into more palatable chunks over a decade was funding possible.

The whole process of constructing ISS was a bit skewed by NASA's insistence that STS was the solution to all lift problems. Hard to say how it would have played out with disposable rockets.

[Albert VDS]

Sure that's a limiting factor, but that's not the point.

The point is that a bigger rocket equals faster and cheaper deployment of a space station.

[Kryten]

It wouldn't be cheaper, thanks to your massive booster having no way to amortise costs; look at the $/kg to LEO of Saturn V compared to Proton.

[Simon Ross]

It wouldn't be cheaper, thanks to your massive booster having no way to amortise costs; look at the $/kg to LEO of Saturn V compared to Proton.

Errr that was because Saturn V was a man rated booster design, something Proton has never been

[Red Iron Crown]

It's really hard to get a valid cost comparison of different launchers, given that they were built at different times with different capabilities, like the man-rating Simon Ross mentions. Though I suspect Soyuz, a man-rated design, probably has the lowest cost of all given the sheer number of launches that help amortize the development costs.

[Streetwind]

SpaceX is actually undercutting every other launcher anywhere near the weight classes they can support. Even Soyuz. They make an active effort to be the single most affordable option, always, even if it's by only a couple dollars out of several thousand per kg.

I've wondered about this strategy before. They must be banking quite a bit on long-term income, because right now they are fielding their contracts with a launcher that's basically still in-development (it's no coincidence the Falcon 9 v1.0 got replaced by the v1.1 variant only a couple launches in) and thus, no matter how well-designed and efficient, has not come anywhere near amortization. At the same time, they're going through at least one new Merlin engine generation every year, have other engines besides that cooking up as well, are working on completely new flight systems such as the Grasshopper, and have at least two future launch vehicles in development along with a fresh-out-of-development spacecraft and its still-in-development successor. And the big cost saving mechanism they're advertising - he reusability of their launch stages - hasn't even posted a successful internal test, let alone been applied. I can only guess they're currently cannibalizing the funds they got from contracts for launches in 2015+. The mind boggles when imagining how to turn that kind of venture profitable. Elon Musk is a brave (and somewhat scary) man.

In that respect, the Falcon Heavy is probably their ace in the hole. They don't need another super rocket that can beat the (still theoretical) SLS... they just need to pull off their launch demo this spring. If they can show that this rocket exists and flies... The Falcon Heavy carries twice the payload of the next-heaviest currently active launcher, the Delta IV Heavy, and SpaceX claims that launching it only costs a third of said Delta IV. Such a launch vehicle could create a whole new market, making it actually economically viable to have launch masses this large. And the Falcon Heavy's R&D costs should be reduced by the fact that it's essentially a trio of Falcon 9's strutted together.

A very Kerbal solution, in my opinion

[Kryten]

Errr that was because Saturn V was a man rated booster design, something Proton has never been

Two issues;

a) You're wrong, Proton was built from the ground up as a crewed launcher for the L1 program.

You're wrong, the cost of 'man-rating' is going to be irrelevant, given a rocket of this size is going to require very high reliability, crewed or not, because of the immense financial risk involved with the gigantic institutional payloads.

Anyway, you missed the entire point of my post, which was comparing amortised and non-amortised costs. An individual Saturn V, including launch, was about $1 billion in modern money, compared to about $100 million for Proton-Proton still wins in terms of $/kg, but not by a huge margin, and it's easy to see how improvements to Saturn could have beaten it. However, if you include the total program costs, that Saturn-V jumps to a ridiculous $4 billion, whereas Proton stays almost exactly the same. Why? Because Proton has flown almost thirty times as much.

Edited February 19, 2014 by Kryten

[SargeRho]

Musk actually created SpaceX knowing full well that it may not create any profit.

Also the SLS is being built, it's thus not theoretical at all.

[Streetwind]

A launch system stops being theoretical the day it launches successfully for the first time, and not a moment sooner, good sir No amount of planning, advertising, failed tests and grounded parts display changes that. Too many promising projects were canned a few meters before the finish line. It must fly. And that's why the Falcon Heavy, too, must fly. Until it does, it will be theory. And SpaceX knows they can't make money off of a theory.

Now, the fact that SpaceX may never turn profitable? That's genuinely new to me, and surprises me even more. It may be very altruistic of Musk to throw his fortune towards accelerating space development, but ultimately we need space development to be sustainable. Because when there's money to be made, that's when the broad public starts taking an interest, and things really accelerate. As such, I hope SpaceX can at least manage a "black zero" at the bottomline eventually.

[SargeRho]

It stops being theoretical the moment the decision is made to build it. Its stats of course, are theoretical until it's launched.

He created SpaceX with the goal to make Humanity a space faring civilisation, not to make a profit, although that would be nice.

Parts of the SLS are flight tested even. Orion gets its first space flight I think this year, the LES is tested, the 5-segment booster is both ground and flight tested (Ares 1-X), and the engines are basically SSMEs.

[Scotius]

A launch system stops being theoretical the day it launches successfully for the first time, and not a moment sooner, good sir No amount of planning, advertising, failed tests and grounded parts display changes that. Too many promising projects were canned a few meters before the finish line. It must fly. And that's why the Falcon Heavy, too, must fly. Until it does, it will be theory. And SpaceX knows they can't make money off of a theory.

Now, the fact that SpaceX may never turn profitable? That's genuinely new to me, and surprises me even more. It may be very altruistic of Musk to throw his fortune towards accelerating space development, but ultimately we need space development to be sustainable. Because when there's money to be made, that's when the broad public starts taking an interest, and things really accelerate. As such, I hope SpaceX can at least manage a "black zero" at the bottomline eventually.

I wonder if "boosting" of space business is not exactly what Elon Musk is hoping to achieve. Especially with his relatively cheap and affordable rockets. If he can offer reasonably low prices for launching medium-to-heavy payloads, companies that could not afford to send their own satellites until now might flock to SpaceX. It will create bigger market, which in turn will allow for even lower prices - and so on. Finally space market might become self-sustainable - and who will control a huge chunk of launching biz by then? Best of luck, Mr. Musk.

[Red Iron Crown]

I thought SpaceX was the main component of Musk's plan to retire on Mars.

[Nibb31]

He created SpaceX with the goal to make Humanity a space faring civilisation, not to make a profit, although that would be nice.

SpaceX is a private corporation, not a non-profit organization or a money sink for his personal fortune. In order to survive, it's going to have to generate revenue.

[SargeRho]

A money sink for his personal fortune is exactly what it is, currently.

[Streetwind]

It stops being theoretical the moment the decision is made to build it.

I don't think you can use that reasoning. If it came to that, the soviet N1 moonshot would be as real a launch system as the Saturn V, because at one point someone decided to order it built. But the program was canned before the rocket ever managed a single test without exploding. It never reached the edge of space, and never flew a successful mission; in other words, the theory behind it was never realized.

The Energia Buran, on the other hand, is as real a launch system as the space shuttle. It was canned too, but not before managing a fully successful launch where its payload (the Buran shuttle) achieved the intended orbit. That means regardless of its cancellation, it had that one flight. It launched something into orbit. Thus it is not theoretical.

[SargeRho]

The N1 is as real as the Saturn V. Not functioning and not existing are different things.