New Rocket Engine Successfully Tested 162
inetsee writes "XCOR Aerospace announced that their new methane-oxygen rocket engine has been tested successfully. This is reported to be the first successful test of an engine using the combination of methane and oxygen as fuel. The fuel has higher specific impulse than kerosene and oxygen, but until now has been thought to have too much 'technology risk'."
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Re:Methane? (Score:4, Informative)
I'm sure they are, for small-scale organic ranchers catering to prestige restaurants. For the other 99.98% of the market, cattle are still king. Compare the numbers: roughly 1.3 billion head of cattle worldwide (100m in the US), compared to only 350,000 bison remaining in the world, with 250,00 being raised for meat.
That means that bison have about
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I just think it would be funny to drive around and see all these weather balloon's sticking out of the ass end of cows.
Little bit disingenuous (Score:5, Interesting)
There hasn't been much use, because rocket design has been on a different track than XCOR. Kerosine engines are primarily used for their high thrust to weight ratios, which help get a rocket off the ground. Once the rocket is in flight, the first stage is usually dropped in favor of a more powerful engine, such as Liquid Hydrogen/Oxygen engines. LHOx has the highest specific impulse of any fuel deployed to date; even more efficient than the methane-oxygen engines they're proposing.
The problem is that XCOR is working on a different track than NASA and the large rocket manufacturers. They're focusing on winged takeoff and landing, where high thrust to weight ratios aren't as important, and can be sacrificed for greater efficiency. (For comparison, the kerosine F-1 engines on the Saturn V produced 1.5 million lbf compared to the 7,500 lbf targetted by this engine.) So the methane-oxy engine development has less to do with politics, and more to do with the practical matters of meeting the targetted design goals.
No (Score:5, Interesting)
No, it has more to do with the subcontract they have with ATK to do research for NASA LINK [xcor.com]. This pays the bills while they play with their winged rocket-plane.
For comparison, the kerosine F-1 engines on the Saturn V produced 1.5 million lbf compared to the 7,500 lbf targetted by this engine.
They were also pumping a lot more fuel and oxidizer per second (much larger m_dot). This is a small engine mounted to the back of a trailer. You could (almost) wrap your hands around it. The F-1's chamber is quite a bit bigger.
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Are they contemplating the Final Solution for trailer trash or something?
First they came for the trailer trash and I didn't say anything because I wasn't trailer trash.
Then they came for the phone sanitizers . . .
On the other hand it's a free ride into space. Maybe I'll get a mullet and rip the sleeves off my t-shirts or something. Take that Ansari.
KFG
Re:No (Score:4, Interesting)
Good catch. But it's still not being developed for a traditional launch system. According to their website, this engine would be used for the lunar -> LEO transfer stage on the CEV. Which again makes the thrust to weight ratio less important, and again non-comparable to kerosine engines. (From what I understand the Apollo Service Module used a hydrazine engine for the transearth injection.)
Agreed. However, I don't have the actual Thrust to Weight ratios for the XCOR engine, so all I can do is point out the differences in their thrust. If you have the actual ratios, feels free to chip in.
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CEV/Constellation is becoming our "traditional" launch system.
If you have the actual ratios, feels free to chip in.
Hehe... no I don't. XCOR is keeping the numbers close to their chest. As they should... the numbers belong to NASA under contract. But you can back out a rough guesstimate since they gave you the thrust.
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No, they're the new hotness! *sizzle* :P
Sorry, when I refer to "traditional launch system", I mean a vertical take off rocket. The CEV program covers a huge number of vehicles and engines. What I'm referring to is that the methane engine is not planned for use as the first stage of a vertical takeoff; which is the area where kerosine is most commonly used.
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At the moment its a piece of crap (thrust to weight wise) - it is a heat sink design, so there is extra copper around the throat of the engine
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Holy Christ, are we still allowed to do that? Why didn't I get the memo?
Now all we have to do is do something about the design goals and we're set.
KFG
Re:Little bit disingenuous (Score:4, Insightful)
That's misleading. "This engine" is strictly a prototype so they can develop a much larger version. Comparing a production engine with an early, heavy in development prototype simply does not make sense. From the article, "The 7,500 lbf engine is the first of its kind...", and, "Currently, the engine is a workhorse prototype...". I don't see what their target thurst is, but one can assume it's much larger than 7,500lbf.
Re:Little bit disingenuous (Score:4, Interesting)
7,5000 lbf is the target for this engine. It builds upon the 50 lbf XR-3M9 [xcor.com] and 10,000 lbf 5M12. As pointed out by another poster [xcor.com], XCOR claims "the new Orion Crew Vehicle main engine design will be an interpolation between these recent designs."
Additionally, XCOR is advertising their engine developments as a possible base for methane-breathing Jet engines that would work in Mars atmosphere. (A very interesting development, indeed!)
BTW, if you have the projected thrust to weight ratios, please share them. I hate having to use the thrust values, because it can be (as you said) misleading. Unfortunately, I don't have the values for the XCOR engine. What I can say is that LHOx > methane > kerosine in terms of specific impulse/efficiency. In terms of thrust to weight, the formula is exactly reversed where kerosine > methane > LHOx. There are very few cases where both the thrust to weight and specific impulse are high. (Orion Project and MPD thrusters [wikipedia.org] are the two I'm aware of.) Otherwise, they tend to be inversely proportional.
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You sound like you're more in tune with following these developments so I many very well be out in left field here.
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upper stage engines are usually less powerful than first stage engines.
An LH/LOX engine will have a higher specific impulse than an RP-1/LOX motor but a lower density impulse.
That is what methane/LOX more is trying to address. It makes a better first stage than LH and a better upper stage than RP-1.
It could be a good compromise for a SSTO system.
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That was a mistake. It was supposed to say, "more efficient".
Agreed. The logistics of actually developing an SSTO would be difficult, but as I said in another post, more companies working on space technology can only be a good thing.
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This is just a difference in power curves. Once you're at Max-Q, there's not much point in maintaining more thrust than necessary to overcome drag losses.
The older rockets struggled to reach space in comparison, and needed more stages to keep accelerating. As a result, rockets like the Titan family used a large number of stages, most of which are unnecessary in a mo
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You may want to look that up.
The Titan I and Titan II each had two stages. Not what I would call a large number.
The Titan II is what they used to put the Gemini missions into orbit.
They later expanded the family in the Titan III and IV which used strap on solid boosters and often a third stageand or what they called a transtage.
In fact the Atlas one of the US's first ICBM and one of i
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Ahem [wikipedia.org]: "The Atlas boosters required extra strengthening in order to handle the increased weight of the Mercury capsules beyond that of the nuclear warheads they were designed to carry. Little Joe was a solid-propellant booster designed specially for the Mercury program."
In other words, the Atlas had a mostly useless payload capability, and was re
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Here is a good link to about the "Little Joe" http://www.astronautix.com/lvs/litlejoe.htm [astronautix.com]
The Little Joe is a long time favorite of scale model rocket builders.
They never used strap on boosters for Mercury flights. In fact the Shuttle was the first us in the US of large solid boosters in the US.
There where plans to us them with the X-20 and MOL but they where never flown.
So.
1. No they didn't use
Mars exploration (Score:5, Interesting)
Old idea waiting on execution (Score:3, Informative)
Love the scare quotes.... (Score:3, Insightful)
(I mean, as in, let me go combine hydrogen with carbon and oxygen, and see what happens......)
Not as bad as some other rocket fuels... (Score:2)
Methane rocket (Score:5, Funny)
Wonderful! (Score:5, Informative)
Methane gas is utterly renewable. You can make it from shit [colostate.edu], literally, and without any special equipment [motherearthnews.com]. The only special thing you need is a way to compress it [repp.org] to store it... say 200 psi tops? The only thing I can't find is a small compressor suitable for this purpose on a household scale. You can actually just run your waste into the bottom of a pond along with a steady flow of water, tent it, and capture methane - you bubble it through water to purify it. The compressing is the only issue left...
Side note: While searching for goodies I found this url [sodalitasart.com] which attempted to root my computer. No idea how successful it was, I'm off to go run defender and spybot.
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Petroleum is utterly renewable. You can make it from plants.
KFG
Re:Wonderful! (Score:5, Funny)
M-
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The number of people who have apparently never talked to an alcoholic baby boomer is truly amazing. Lucky bastards. Basically all of them have said at some point in their lives "just one little drinkypoo".
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Mom? Is that you?
Protestor sign of the future (Score:4, Funny)
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There are several farms here in Vermont taking care of all of their electrical needs, plus selling some back to the utilities, all on Cow Power. Though now that you mention it, turbines are generally used at large-scale powerplants, for their efficiency. I wonder at what scaling point that becomes true. Perhaps the farm still doesn't need a rocket engine, but it would be better off with a methane-powered jet engine instead of its current I.C. engine.
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Yes we have all seen the 80s documentary beyond thunderdome.
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put it in your freezer (Score:2)
\not sure how much pressure could be gained this way, would have to crank the numbers
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IANAP(hysicist) but it seems to me that the compressor would still only be able to compress the same mass of air per stroke. Also it's probably going to cost you more energy to cool and then compress it than to just keep compressing it. If you want more pressure, you just use a multiple-stage compressor.
Really, this is sweet. (Score:3, Insightful)
Having one organization, with one budget (NASA) works fine when you've got a big enough budget. However, politics and manpower constraints limit the number of avenues you can explore. Like with computers, having a monolithic space technology architecture can lead to a single point of failure.
What if a component is outlawed, or becomes extraordinarily expensive to produce? You end up with mountains of unusable applied technology.
This test demonstrates that the practical science behind space flight is getting diversified, and that can only be a good thing for ensuring the future of space flight.
Um. Hate to bust your bubble (Score:5, Informative)
See, XCOR can't make money flying their rocket-planes around so they have to have government contracts to foot the bills. It was like this before the X-prize and will remain to be.
Now the X-prize itself and the X-cup? Yes, cool. But credit where credit is due. This is NASA research, not X-Prize stuff.
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After all, NASA -> BAD! Anything but NASA -> good!
What's sad is, there really seem to be people who think like this. I wonder how many people would change their minds about the project, based just on your post.
Cattle powered (Score:5, Funny)
I can see it now - "Where do you stupid bovines think you're going? The mooooooooooon?"
Just a wild thought.. (Score:3, Interesting)
Additional cost savings? (Score:2)
Could you mix LOX and liquid methane in the correct proportion in the same fuel/oxidizer tank and eliminate 1/2 of the pumps/plumbing, etc?
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Obviously, I know nothing about the operational pressure ranges, but one can easily infer that mixed-phase flows would likely result if you tried to use both from a single tank. I wouldn't want to see what that would do to a rocket engine turbopump. (Well, actually, since high-speed cameras are fairly cheap the
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Is it me or does that sound _really_ dangerous?
I know, let's put a stupidly large, explosive mix of fuel/oxidiser in a tank under very high pressure and hope nothing ignites it.
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2. If you could it could be hard to keep them in uniform mixture.
3. Yes I would call it a bomb.
In theory I am pretty sure that you could mix NOX and Propane under pressure but that would also be a really bad idea.
Re:Additional cost savings? (Score:5, Funny)
Sure you could do that... if your goal was to simulate the blast effects of a small nuclear explosion.
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Of course, if your nozzle could spit things out at that rate, why bother with combustion?
Yawn! (Score:3, Interesting)
Another chemical engine. Been there, done that. Where are all those cool nuclear and ion engines I've been reading/hearing about for the last 30 years? You know the ones that promised us that mars was a couple weeks away and Jupiter was just a couple of months?
We tried out that ion engine a few years ago. If I remember it worked perfectly. Why haven't we put that in to service. The last probe we launch, pluto express, still used the tried and true brute force approach. It will take it about 20 years to get there. Where if we had strapped a nuclear powered plasma rocked they have been testing for the last 20 years I could already be bitch'n about how dull pluto is.
Come on guy's you've had the plasma rocket in a bottle for 10 years. Lets take it up, strap it to something, and see what the bitch can do.
Yes, I know nuclear plasma and ion can't get us off the ground so we'll still need chemical for that, for now. And I know you have to crawl before you can walk, but we've been crawling for 60 years now. Hell, we are still using the same basic technology that the nazi's where lobbing into London.
Let's get off the can and do something new for once.
Re:Yawn! (Score:4, Informative)
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The treaty should be changed if it hampers the progress of our species. No, we shouldn't be setting off nukes in low earth orbit, but we should be using them (or at least open to the possibility of usng them) farther out.
Another good idea is the nuclear thermal rocket [wikipedia.org]. Basically, you use a nuclear reactor to super-heat the propellant, which then expands (quite rapidly) pushing the craft forward. The exhaust gas isn'
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substantially altering something is significantly more difficult/time-consuming than it was to make the thing in the first place.
how many years of talking and head-bashing do you think it took to make said treaties? it will take a lot more to change them.
I'm not saying that the treaties shouldn't be changed, but it will take time.
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Die-hard Luddites still have a say in our society because somewhere along the line we perverted the notion of freedom of speech into the notion that every proposition, no matter how factually bankrupt or logically absurd, is equally worthy of continued attention. The marketplace of ideas ensures that each idea is given a fair hearing at least once, but it shouldn't represent that all ideas are similarly good. Everyone has a right to be heard, but not a right to be believed.
Exotic propulsion technologi
Right. (Score:2)
Moon Direct (Score:2)
I am such a geek. (Score:2)
Banding? (Score:2)
Shock diamonds. (Score:2, Informative)
You can get some really interesting designs out of high-speed flows, especially when you throw in some bright combustion.
obligatory Muppet Show quote... (Score:2)
Done already by South Korea (Score:4, Informative)
I am partial to US technology in most matters but South Korea successfully tested [hobbyspace.com] a 20,000lb thrust methane engine last year. I believe that Japanese have something similar.
Re:risk? (Score:5, Informative)
Re:risk? (Score:4, Funny)
If the astronauts run out of rocket fuel and get stranded they can always eat beans.
Re:risk? (Score:5, Informative)
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Ohhh, and we really shouldn't (as microbiologists) mention methane without pointing to the Volta Experiment [washington.edu].
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Same reason god made farts smell - for the benefit of others.
Re:risk? (Score:5, Funny)
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It's the odor the driver of the Impala (that the test platform was mounted to) smelled.
BBH
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Re:spelling request (Score:2)
http://en.wikipedia.org/wiki/Alkane [wikipedia.org]
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I actually have a crapload of methane to donate, whom do I contact?
Bumper sticker: Save Gas - Fart In A Jar
Metric or Imperial? (Score:4, Funny)
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Re:Metric or Imperial? (Score:4, Funny)
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See my post [slashdot.org] for an explanation.
FWIW, I think it's a good thing that companies like XCOR are exploring other engine options. NASA only targets developments that are useful to NASA, potentially leaving behind massive swaths of rocketry that could prove useful in the future. By having more third parties working on rocket technology, we're increasing the experience in the industry, lowering costs through economics, and hop
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Interpretation of 'risk' (Score:5, Informative)
NASA uses a scale called Technology Readiness Levels (TRL [nasa.gov]) which you can read about if you like. Operating this device and documenting it can help raise the TRL of methane engines.
Additionally, it is a 'risk reduction' effort because it could be a replacement for the engine of the CEV which right now is (I think) kerosene+LOX. If that falls through for some reason (what, I don't know...) there is a second option on the table. Again, reducing risk.
And yes, according to Zubrin, we can manufacture methane on Mars where the CEV will be headed in 15-20 years, so an adaptation of this might be a retrofit to the CEV someday. (but please, be critical thinkers when you read Zubrin...)
That is all.
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They want it, not need it. (Score:3, Informative)
NASA has wanted to have a methane engine option for quite a while, but since they have other functional options, they haven't been willing to take money away from other projects to develop it. It's a risk in the sen
Re:Why hasn't it been worked on? (Score:5, Informative)
Methane engines are interesting, but they're no panacea. Methane lines on the spectrum between kerosene (dense, comparatively high temperature, moderate ISP) and hydrogen (sparse, extremely low temperature, high ISP). Specifically:
Hydrogen@20K: 70kg/m^3 (fuel**), 358kg/m^3 (bulk**), 455.9 (ISP sec@100:1/20MPa)
Methane@112K: 423kg/m^3 (fuel), 801kg/m^3 (bulk), 368.3 (ISP sec@100:1/20MPa)
Kerosene-based (RP-1)@298K: 820kg/m^3 (fuel), 1026kg/m^3(bulk), 354.6 (ISP sec@100:1/20MPa)
Note that it's a rather small ISP gain over kerosene -- not close to the performance of hydrogen -- yet its density is halfway between kerosene and hydrogen. While a small gain in ISP can be a big boost in performance, that's a pretty big density hit.
A fuel that I find interesting is propane. While at its boiling point, it's not that interesting:
Propane@231K: 582kg/m^3 (fuel), 905kg/m^3 (bulk), 361.9 (ISP sec@100:1/20MPa)
But cool it to 100K, and you get:
Propane@100K: 782kg/m^3 (fuel), 1014kg/m^3 (bulk), 361.9 (ISP sec@100:1/20MPa)
Not only are these attractive numbers, but since the propane is similar in temperature to the LOX, they can share a common bulkhead. Of course, it can't go too much below that, or its viscosity will rise too much (at 100K, it's similar to kerosene).
To make methane significantly more dense, you have to go pretty darn cold (well below your LOX temps), and it's probably not worth hydrogen complexity for a fuel with an ISP like methane.
** - Fuel density is the density of the fuel alone. Bulk density is the density of the fuel plus stochiametric amounts of liquid O2.
Re:Why hasn't it been worked on? (Score:5, Informative)
Speaking of pumps -- what do others think of the flometrics [flometrics.com] design? I have to say, I like it.
Re:Why hasn't it been worked on? (Score:4, Informative)
Re:Why hasn't it been worked on? (Score:4, Interesting)
I think it is interesting, huge weight savings over a pressure fed with none of the high-speed parts of a turbopump. Flowmetrics wasn't the first to come up with the idea although they were the first to put it on a rocket and have patented several ideas relating to it. I'd like to see it running in a bigger concept than the SDSU rocket [sdsu.edu] though. (Steve and Carl, faculty advisors for the projects work at Flowmetrics)
(They were pumping martinis at the Joint Propulsion Conference 2 years ago... very nice... and yummy)
Isp vs. Thrust (Score:2, Informative)
Re:Isp vs. Thrust (physics) (Score:3, Informative)
Isp relates pretty directly to exhaust velocity. The difference is a unit conversion and some small correction factors.
Speed and force are separate ideas. Thrust is proportional to Isp *times the mass flow rate*. Throwing something heavy out the exhaust gives you more kick, but lifting and carrying something heavy is inefficient.
Ion drives show the tradeoff really well. They have spectacular Isp but the mass flow rate is a trickle. They have tiny amounts of thrust, but great fuel efficiency.
Speci
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It isn't rocket science
The most important concept being taken for granted here is "specific impulse" or I(subscript)sp. It's pounds (force) of thrust divided by fuel burn rate in pounds (weight) per second. If you have an Isp of 300, then (oversimplifying outrageously) you'd use 1/300th of your fuel to hover for a second.
Higher Isp is very good. It appears in an exponent in the "rocket equation" (see Wikipedia). Small improvements make big dif
Armadillo too is considering methane (Score:5, Interesting)
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Re:Risk? (Score:5, Interesting)
The risk being talked about here is program risk... ie... the risk that using unproven technology will result in cost and schedule impacts to the project due to unforeseen problems. Not the risk of things going boom (although that can impact cost and schedule too... XD) Using proven, well-understood technologies reduces risk.
Think of it this way... if you're given a task to develop a program for $C dollars inside of Y months, are you going to use a well-established programming language or are you going to go with some new half-developed (but really nifty) one where you're playing debug the compiler as you work on your project?
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The term "risk" has many meanings, risk to life, schedule risk, technical risk, etc...
The example given is perfect. Think of the engine as a the compiler in his example.
LOX/Kerosine and LOX/Hydrogen engines are essentially debugged. They're a known factor, just like the example's "well-established programming language".
Methane engines are still under development and the bugs haven't been worked out ("new half-developed (but really nifty one where you're playing debug the compiler").
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