SpaceX, the rocket company founded and bankrolled by famous PayPal nerdwealth icon Elon Musk, has revealed radical plans for a colossal launcher as big as the Saturn Vs which sent men to the Moon - and has also proposed nuclear-powered spaceships to carry astronauts to Mars. SpaceX plans for future launcher development. Credit …
Over 40 years on from Apollo and they are planning a rocket that can lift the same weight. Woooo.
Also noticed that the X Heavy seems to use quite a few rocket engines. The Russians worked on that and failed because of trying to run the engines in sync - I'm sure technology has moved on a lot since then though.
It's the 9-Heavy uses lots of engines, the standard Falcon 9 has (surprisingly) 9 engines and the Heavy is 3 strapped together for 27 total. The basic X has only 3 of the bigger engines so the X-Heavy has a total of 9 across the 3 cores.
The Soviet N-1 had problems because all 30 engines were fed from a single pair of tanks which made plumbing and wiring a nightmare, in flight working engines got shut down instead of faulty ones and rapid disassembly took out neighbouring engines as well.
Russians solved that problem
The N1's real problems were down to quality control (one rocket exploded when either welding slag or a loose bolt was sucked into a turbine) - so they fitted filters, and to the computer software controlling the engines - which they gradually debugged.
The N1 was killed by Brezhnev before its fifth test launch which the engineers were confident would work. But America had got to the Moon, the Soviet economy was beginning to stagnate and they needed to find the money to design a rival to the Space Shuttle.
I'd be more worried that they're talking about a new rocket design that can't survive a single engine failure. Saturn could (and did) complete its mission with one engine out. The Shuttle can get to orbit on two main engines (one in the last few minutes of flight). Let's hope they don't think of putting people on top of that one.
Besides, why are we buggering around with rockets at all? Project Orion now please - 6000 tonnes to orbit on the back of 800 nuclear explosions - what's not to like?
Number of engines
Russia's failed N1 launcher, intended to beat Saturn V / Apollo to the moon, used 30 engines in it's first stage. The Saturn V used five. Energia (the utterly awesome Soviet-era designed heavy-lift booster that sadly only flew once before the collapse of the USSR doomed it to history) had four. The Falcon 9, the biggest of SpaceX's two launchers so far, has a nine engine first stage.
The vibration problems on the N1 were solved; it was the tendency of engines to explode when they failed that turned out to make the odds of a total loss accident too high.
It's hardly surprising we haven't moved on much. The theoretical abilities of chemical-powered reaction motors are basically fixed by the physics. You can tweak the efficiency through slight improvements to the rocket motors, better control of the burn, better engineering materials and so on, but the gains become ever more marginal. Ultimately to lift more you need a rocket that gets linearly heavier with the payload (and, obviously more complex). There is nothing that is going to change that short of a wholly different approach.
We only need to look at jet aircraft. Passenger jets, in pursuit of fuel efficiency, actually travel slower than those designed in the 1960s, and the Concorde experiment demonstrated that to go a lot faster involved disproportionate expense which the market couldn't fund. The fastest military aircraft are still no swifter than those designed in the 1960s (the really big gains are in control, electronics and weaponry).
So it will be with chemically powered rockets - these huge lifters required for inter-planetary travel can only be funded when something other than economics is the issue. In the 1960s there was the cold war and a wealthy US government to fund it. That's no longer the case - maybe the Chinese could find the funds and will to do it. But be under no misunderstanding. The problem is fundamentally that limited by the physics of chemical rockets.
Quite a few? Quite a few less!
I suspect you're thinking of the Soviet N1 rocket, whose first stage, with 30 NK-15 motors, has got more than three times as many motors as the Falcon X Heavy's is supposed to get--noting, of course, that the XX and X Heavy are supposed to use the Merlin 2 motor, which is a pretty huge motor compared to the NK-15. That was, however, HARDLY the N1's only problem. No, there were plenty:
* Soviet inability to make bigger engines due to insufficient industrial capability, as well as any other problems with building a huge moon rocket, whose first stage has thirty freaking engines, which might follow from inadequate industrial capabilities. Dangerous engineering compromises to account for such shortcomings were pretty commonplace in Soviet engineering. Hell, just look at their RBMK power plants.
* Problems with the kind of plumbing you need to make the motors work on a rocket whose first stage alone has thirty motors; furthermore, the motors were of the closed cycle/staged combustion cycle variety, which are more efficient than earlier designs but require more complex plumbing--which is a problem when getting /any/ rocket with that many engines would be a pretty amazing feat of pipework.
* The Soviet tendency to test things as little as feasible, because testing is expensive and the Soviet Union was kind of poor. In addition to lack of funding, the rocket could not be assembled completely until it was at Baikonur Cosmodrome, which further restricted testing.
What do you get when you have a largely untested, underfunded, and spectacularly complicated design with a relatively new kind of engine, all made in a country that, by fiscal necessity, had to do everything pretty much everything as cheap and dirty as they thought they could get away with? In this case, some pretty spectacular explosions. There were so many things that could go wrong, and so few of them had been tested and corrected before launch. That's a recipe for fiery failure with /any/ rocket, let alone one over a hundred meters tall with several dozen motors and a maze of plumbing that'd make even the Mario Brothers run screaming.
SpaceX, by comparison, has good manufacturing capabilities, good metallurgy, extremely rigorous testing practices, and a simpler and more reliable design--both for the motors and the rockets as a whole. In general, SpaceX's stuff is simpler, less fragile, and better made, and SpaceX is a lot better about testing their rockets than the Soviet space program.
The Russians did solve it
Take a look at the bottom end of the Soyuz booster. It uses 24 rockets firing simultaneously, and "by the year 2000 over 1,628 had been launched with an unmatched success rate of 97.5%" so it seems to work.
The first stage of the Soyuz-U (and most other rockets derived from the R-7) consists of four strap-on boosters (each with a single RD-107 engine) around the second stage core (with a single RD-108 engine). The RD-107 and RD-108 engines have four fixed combustion chambers apiece, but are considered to be single engines because they each have a single pair of turbopumps feeding RP-1 and liquid oxygen to the combustion chambers. In addition, the RD-107 has two gimballed verniers, while the RD-108 has four.
So, depending on how you count it, a Soyuz-U either has five engines firing at launch, or thirty-two thrust chambers.
It's all about money, eventually
"The Soviet tendency to test things as little as feasible, because testing is expensive and the Soviet Union was kind of poor."
At most, a half-truth. Reliability wasn't even a design goal. Why would it be? There were more volunteers they ever could use, who cares? Failures weren't published so what's the problem?
If you haven't noticed, SU was very fond of heroes and those usually end up dead.
Also they were in hurry, just like Nasa which caused a shuttle to blow up, nothing new in here either. "Not enought resources" might be true but poor? No.
There are many problems who can't be solved by throwing money to them, even if some people think so. You need a lot of brilliant people and those are always a limited resource, in any country.
Judging Soviet Union designs by US-standars is also a big mistake and frankly, I can't ever understand what is the constant fuss of some astronauts ending dead: Everyone knew it was very dangerous and there is a lot more of astronauts available, any time.
"Best effort" (in allotted time and money) is enough.
You also use "Cheap and dirty" as derogative, which tells about your attitude more than anything in reality. Example: Kalashnikov. T34 (tank).
US has a very long tration of making hugely over-engineered anything which ends up being as unreliable than cheap solution just because of enormous complexity which exceedes the capabilities of the designers. KISS is something they haven't even heard of. (Any modern fighter jet in US needs 5 service hours for one flight hour and have operational capability of minutes, not hours.)
But of course: The company building these designs make a huge profit, they _have to_ use complicated (and extremely expensive) solution.
"Over 40 years on from Apollo and they are planning a rocket that can lift the same weight. Woooo"
Yes, but that's not the whole truth: The cost of lifting that has dropped to less than a tenth from what it was from 40 years ago. That's progress as well.
Much like TV: It still shows a picture to you, just like it did 40 years ago and you might as well ask that where is the progess in that case?
You got the wrong idea.
Oh, hey, don't get me wrong. Cheap and dirty can be just fine a lot of the time; the benefit of it is that a lot of Soviet designs ended up being simple and rock-solid. I love my Mosin-Nagants, for example--one of 'em is over seventy years old and it still shoots great. The action is still smooth as butter, and the thing is so easy to take apart and clean; furthermore, the accuracy is pretty impressive. I've had Lego sets that were harder to service.
But to claim it's a "half-truth" that the country was strapped for cash and cut corners on account of it is just a baldfaced lie. Where were their supermarkets? Where were their department stores? Those were pretty hard to find, but the graves of peasants who starved to death by the tens of millions were quite plentiful. Don't tell me that country wasn't poor.
You assert that the country wasn't poor and that all this business about safety was just a matter of priorities, but it's a pretty hard argument to make when just about every aspect of Soviet industry has had every corner cut that could be. They couldn't make engines like the Saturn V because manufacturing them was too expensive. They stuck with light-water cooled, graphite-moderated power plants because manufacturing something safer with a negative void coefficient was too expensive, and more western-style designs seldom appeared outside of naval reactors. They never managed to build a big nuclear-powered aircraft carrier like the Nimitz class because the navy thought they were too expensive--despite remarks like "Why are you splitting hairs? Make an aircraft carrier like the Americans have, with that kind of aircraft fleet." (One ship fitting the bill was finally under construction in 1991 and never finished because the country collapsed.) For that matter, look at how long it took the USSR to come up with four-engine bombers. Sure, they got 'em eventually, but it took longer. Likewise, sure, they worked out most, if not all, of the problems that doomed the N1 rocket project (though not before the project was cancelled outright), but it took longer.
They played catch-up with nuclear weapons technology, they played catch-up with nuclear submarine technology, they played catch-up with naval architecture, they played catch-up in aerospace engineering, they played catch-up with manufacturing, they played catch-up with just about everything. Why? Because it takes a long time to turn a country of agrarian peasants into something that can make moon rockets. You need the mining, you need the steel production, you need the tooling, and you need all the infrastructure that stands behind those, and it takes more than a few five-year plans to get that. They had some brilliant engineers and scientists, and they made a fine effort of it and managed to more or less keep up with western military capabilities, but it came at a price, and when you're in a position like that, obviously safety, testing, and things like that are going to be lower priorities--especially when everybody's pretty sure that military parity with the west must be maintained at /all costs/ by /whatever means necessary/. Think for a moment about what "all costs" and "whatever means necessary" might entail. The west thought the same way, but had the economy to back it up--so our nerve gas plant workers at least got good protective suits that didn't expose you to some funny isomer of VX when you bent over too far. We could spare the extra few bucks. They couldn't.
1. Yes 30 Motors and their plumbing are very complex, but what you fail to cover is that 30 small motors without the need for gimbles makes for a much shorter and much lighter configuration, this actually helps with balancing the rocket, which is a much more complicated task than the plumbing system. In addition, the simplification of the attitude control system compensates for this somewhat.
2. True this programme suffered from problems, but if you read up on it, most of the plumbing problems were due to the way the rocket was transported to the launch site.
3. The programme was notorious for being underfunded, the main reason being to keep it as secret as possible so large funds could not be transferred to prevent arousing too much suspicion.
The rocket was assembled at the factory, but it needed to be dismantled to be transported to make it to Baikonur, due to the transport links and the shear size of the thing.
This assembly/disassembly/assembly is noted as one of the key points in the potential issues with the plumbing system.
Using multiple smaller engines cuts development costs as you can scale up the number used and people wonder why the Space shuttle costs $1bn to launch and Soyuz costs $30m!
Change of management mid programme didn't help the situation.
Space X have done very well and I wish them all the best, however the Soyuz has had more launches than any other, 898 according to wikipedia with 24 failed launches, none of which were manned and is considered by many to be the safest launch system in the world.
The Soviets also had the wisdom to evolve what they already had rather than to start with a clean sheet of paper everytime.
I'm not saying the Soviets were perfect, neither was any other nation, but at the same time you are trying to compare something that was done 40years ago to something thats been done in the last 8 years.
always in the future
Ever notice how Obama always talks about what will happen in the future?
"The president has said that a new, unspecified heavy lifter will be selected in 2015 for use by American astronauts as they head out first to nearby asteroids and then onward to the red planet."
Mines the one with the layoff notice in the pocket.
Yeah seems like......
...he's kinda expecting to get a second term.
Way things are going I wouldnt bet on it.
And yes I was pleased he got the job. Just he hasnt seemed to have done much with it.
Going back to the point about not much progress in 40 years. I think the issue is that rocket science had reached a pretty mature level some time ago. Its limited by the products available for the combustion (which arent that efficient for lift really).
In effect the payloads mentioned are probably the limit on whats physically/financially feasable.
To get more up there will take some new form of propulsion.
Personally I say just do one mega Orion launch to get 10000 tons of materials up into orbit and be done with it.
Yeah it's weird...
It's weird to have a President with a plan and a schedule. Makes me feel uneasy. Hopefully we bomb someone for no reason suddenly. Then things will feel normal again.
By 2015 the USA won't be on Mars. By that time they would have gone the way of the Soviet Union.
Pretty mature level though.
What you can do though is to make cheaper launch vehicles. Which the Falcon series seem to be. And Musk has the goal of making the Falcon 9 fully reusable.
I'm optimistic up to and including the Falcon 9 Heavy. All its hardware has already made orbit. And two strap on boosters is a tried and tested system. And cautiously hopeful of the Falcon X and X Heavy. But doubtful about the need for the Falcon XX. Possibly dearer than two Falcon X Heavies with a combined payload of 250 tonnes.
Always in the Future?
Yeah, we have to do this stuff in the future, because starting with Bush I, NASA has proposed a series of programs that have never been funded. Because of this, we have no follow on to the shuttle. Even Bush II proposed a program, but didn't bother to do the whole funding thing, that might have put us on the way to that future. The Obama Administration has rightfully dropped that NASA employment package known as Orion (you didn't really think they would ever build that rocket, did you?), and left us with a company that knows they'll make a boat load of money if they actually follow through. Major difference between SpaceX and NASA in that last sentence. Following through. With NASA, you pour in a bushel of money, and you get compost and some jobs. Pour a bushel of money in to SpaceX, you get far fewer jobs, and more actual products. Wow.
why are all the designs based on sex toys?
at least Saturn looked like a series of proper rockets stacked one atop another.
On a more serious note, I thought we were supposed to be into Spaceplanes to orbit by now. Where's my HOTOL to get me to my Space Hotel?
Max Q applies to all types of penetration?
Mine's the one covered in strawberry jel...
Re:why are all the designs based on sex toys?
(Bumper sticker on my flying car - "my other car is a HOTOL")
Will Falcon XXX be ribbed .... for guaranteed controller launch into orbit satisfaction.
amanfromMars 1 ?!?
ONE?!? Oh nooos - they're breeding.
And prolly takin ova the wurld b4 we can leaves!!111!!!
You're thinking of the Falcon Fourex.
the Falcon XXX will also have two spherical fuel tanks at the base.
And what's in the tanks?
Dead Sea scrolls.
"....nor shalt thou burn rocks."
Looks like God not only recommended Kerosene as a fuel but warned us off solid-fuel boosters too. Smartarse.
Just how much is a kikkar and a shekkel? Have SpaceX got their Kerosene / LOX mixture in a ratio approved by God or do we need to get the stakes, faggots and torches out?
....nor shalt thou burn rocks.
Surely this means no nuclear fusion?
Fusion doesn't burn rocks. Burning is a chemical reaction, not a nuclear reaction. And plutonium isn't a rock.
I know, I know...
shurely shome mistake-
you mean fission? Or steam engines.
I do indeed mean fission.
I blame global warming.
God: "This is God talking here!. From now on you won't build spaceships that use atomic energy!"
Shepherds: (blank looks)
God: "Aw, forget about it! YE SHAN'T FUCK GOATS!"
I think that God was warning us to not go forth with the North Korean coal fired booster. The cost in colliers and stokers was just too steep.
...nor shalt thou burn rocks.
No, it means coal.
About 3 Shekel to the Dollar?
No idea where Elon found that quote, but as far as I can tell the Kikkar and Shekel are both units of currency, with 360 Kikkars to a Shekel (maybe), so I don't think this will help much in sorting out fuel/oxidiser ratios ... looks like a pretty dodgy translation to me.
Shekels were also a measure of weight. One shekel is 11.3 grams or 0.4 ounces. The kikar was 60 mannehs, or 3600 shekels. The reason shekels are associated with money is because they were convenient amounts of gold to make coins from.
Not only but also
..there's also that Life of Brian sketch :)
Everything Old is New Again
Hmm, so we're basically back to where we were 50 years ago with the Nova rocket:
Oh, well, at least no one has proposed nuclear rockets again...err, no, wait....
Ok, lunch time on this side of the pond. Let me grab my club and go out into the forest...
Old / new
Sorry, but every bloody rocket looks by and large the same. The reason? The shape of it is quite aerodynamically suited for the job. For the foreseeable future, all rockets will look the same (or it'll be very easy to spot similarities anyway).
Great! Bloody great!
If they hadn't hidden the instructions in a cave two thousand years ago, we could have explored half the Galaxy by now.
dead scrolls a joke
that dead scrolls quote is made up. any stupid person can see that that's a joke.
SpaceX: bringing the old adage about not running before you can walk
right into the space age
One question: Does a "nuclear thermal" rocket produce radioactive exhaust?
Re: Nuclear Propulsion
All rockets produce thrust by throwing stuff out the back end. The faster the stuff is moving, the more push you get for a given amount of fuel. Chemical rockets throw the combustion products (mostly water in liquid fueled engines) out the back end. Nuclear rockets heat up hydrogen by running them through the hot part of a nuclear reactor. The reactor itself stays put. Since hydrogen has a molecular weight of 2, and water has a molecular weight of 18, and gas velocity goes as 1/sqrt(mol weight), hydrogen gets tossed out the back end 3x faster at the same temperature. So roughly it is that much more efficient.
Now, the hydrogen doesn't care how it gets hot. You can get the same performance by focussing sunlight on a heat exchanger, and running the H2 through that instead of making a space nuclear reactor. It would be much safer, less scary for the nucleo-phobes, and sunlight is abundant in space.
only abundant if you're near a sun.....
Rocks, weight, and coinage
In ancient times, coinage served as both a monetary value and as a weight --- in the case of the Shekel and Kikkars -- both related to the Talent (weight) the value of which was based on gold, silver or some other semi-precious metal.
Maybe the 'burning rocks' bit is referring to coal.
When the Falcon XXX hits production will it have a longer thicker shaft and a more capacious head?
one kikkar to 20 shekels?
So that 3600 shekels to 20, or 180:1 fuel:oxidizer? Doesn't sound like stochiometric to me.
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