This is what happens when a reporter has no idea what is going on, and is simply an uncritical stenographer for NASA PAO and officials:
“It is the most complicated rocket engine out there on the market, but that’s because it’s the Ferrari of rocket engines,” said Kathryn Crowe, RS-25 propulsion engineer.
“When you’re looking at designing a rocket engine, there are several different ways you can optimise it. You can optimise it through increasing its thrust, increasing the weight to thrust ratio, or increasing its overall efficiency and how it consumes your propellant. With this engine, they maximised all three.”
The resulting engine, according to Martin Burkey of the SLS strategic communications team, blows everything we currently have out of the water.
“They ‘maximized’ all three.”
Know what they didn’t optimize? They didn’t optimize on cost. Nowhere in that article does it mention that those are actually reusable rocket engines, from the Space Shuttle. But they’re going to throw them all away the next time they use them. Ferraris are expensive, too, but at least they don’t throw the car away each time they take it for a drive.
And aren’t most Ferraris in the shop for maintenance almost all the time? I’d rather have the Honda Accord of rocket engines, personally.
That analogy is stupid on several levels.
I’m not sure how often they’re in the shop, but the description as “Ferraris” is certainly an apt one when cost is considered. A valve adjustment job on a typical Japanese car takes an hour or so (a little longer with Honda Fits), but it’s a major undertaking ($1000+ in labor) on a Ferrari.
Is this a kind of metaphoric comparison, or have you gotten firm prices on this?
I just had the camshaft timing belt done on the 5S-FE 2.2 litre 4-cylinder engine in the 1997 Camry, probably the most popular engine and car in recent history, and after selling me on the belt, the water pump (since we have it apart), the oil pump seals, and valve cover gasket to fix oil leaks, they stuck me for over 1100 dollars. And they didn’t do it right. And when I took it back, showing photos of what was wrong, they denied everything and on top of that wanted $350 for a failed alternator. Which I unbolted and took to an auto parts shop for testing and they couldn’t find anything wrong with it. And the service manager “stands by his technicians” but promised me 10 minutes of his time that I could show him what they did wrong on the timing belt. Which was 8 weeks ago and he no longer returns my e-mails. And this is at the dealership with great word-of-mouth in the community that a basketball coach who did not win an NCAA March Madness championship endorses.
Valve clearances. First this ultra-reliable Camry needs the timing belt changed every 60,000 miles as regular maintenance so it doesn’t fail and strand you on some remote highway, and then I see on the Federal emissions decal that it has valve clearance adjustments?
Yeah, the “Kent” engine on my 1978 Ford Fiesta parked at my dad’s has adjustable valve clearances. I did those when I was still driving the car 35 years ago. It was the kind you adjusted with a set screw with feeler gauges. It was no big deal. Kinda like what I expect on a Ferrari.
The Toyota, however, has “bucket shims” that you have to buy in present sizes from the dealership parts counter. I still can’t figure out from online videos what is all involved, what you have to take apart, and what special tools are needed. I have up on trying and I am afraid to let a shop have a go at this, and the Web suggestion is to leave it alone if the valve clatter isn’t too loud.
So, tell me again the metaphor to rocket engines regarding service on ultra-reliable East-Asian cars?
I once almost bought an old Willis Jeep with an inline 4 cylinder Continental engine that seemed to have about five parts to go with it. You could climb around the hood, in between the fenders, the bumper, and the firewall. Although it would only do about 45 mph, it will probably keep running until the Sun runs out of hydrogen.
I was referring specifically to valve adjustment, not timing belt replacement.
But since you mentioned it, a quick Google search seems to indicate that a Ferrari requires “major service” every 3 years or 30,000 miles, and the cost is $3500 “at a minimum” (meaning they’ll find other stuff that needs work, just like your Toyota dealer). That service includes timing belt replacement (and presumably valve adjustment).
And when you said this, I had to laugh: “It was the kind you adjusted with a set screw with feeler gauges. It was no big deal. Kinda like what I expect on a Ferrari.”
Actually, the Ferrari uses the “bucket shim” approach, too, which involves:
1) Measuring and recording all valve clearances
2) Ordering shims as prep for adjustment, unless if one has spares on hand.
3) Removing the camshafts
4) removing/adding shims to buckets
5) Replacing the camshafts.
Which is why the labor charge is so high.
I don’t blame Toyota for the incompetent/dishonest dealer you took your car to. I agree that replacing a timing belt is expensive, which is why I do that myself (at some cost in pain) rather than pay a shop.
I know that the Honda Fit uses a timing chain, rather than a belt, and valve adjustments (along with spark plug replacements) are scheduled every 100,000 miles. It’s a pricey task ($500-$600, IIRC) because it requires removal of the intake manifold, but the infrequent nature of the service task softens the blow a bit.
Meanwhile, my ’96 and ’99 Civics specify timing belt replacement at 105,000 miles or 7 years, so I guess maybe they’re better designed than the Camry’s.
(apologies to Rand for the OT posts)
So, what about the Big Dumb Booster? You know, the humongous rocket built with ship-building steel, assembled in — a shipyard. With a scaled-up version of the Apollo CM main engine, pressure fed.
If the SLS/SSME is a Ferrari, the Falcon/Merlin a Honda, is the Big Dumb Booster a 1970 Chevy with a stupid pushrod V-8? Valve clearances . . . timing belt . . . ha, ha, ha!
On the old Jag XK engines, you had to file the shims yourself.
If what is going on in the mass-market auto industry is a benchmark for rocket engines, the plans for reliable, low-cost access to space are so in trouble.
Where I work, in among the construction where they were tearing half the building apart, someone was trying to hold a conference, in the big lecture hall I teach, on “Automobile Fuel Efficiency 2020.” What I think that was about is that Mr. Obama has the idea that both cars and light trucks will double their gas mileage by that time, and the entire international auto industry is in a panic, much like our electric power companies as of last week.
Out in the plaza by the odd-looking fountain, I encountered three men in suits. I asked them if they were part of the automotive conference, and they responded yes. I then asked if they knew of steps to insure that maintenance procedures kept up gas mileage — I was going to ask them of the manufacturer’s perspective on whether cars were put out of tune by service shops changing timing belts.
One of them spoke in Japanese, and then another replied to me, “I do not understand your question, I do not speak English very well.”
Forget about the service manager — the engineers are now are “circling the wagons” about scheduled maintenance messing up engine tuning. The President once campaigned on the demand for gasoline being met by proper tire inflation and a “tune up.” When is he flying Ernst Moniz out to look at my Camry after its “tune up”?
Yep, auto manufacturers are optimizing for fuel usage rather than cost, because the Federal government is pushing them in that direction. This is why – if you want an inexpensive car in the US – you’ll have to get something like an Elio, which sidesteps most Federal regulations by being classified as a motorcycle.
It’s also why you have to go to India if you want a cheap four-wheeled car. https://en.wikipedia.org/wiki/Tata_Nano
Spacecraft have been optimized for factors other than cost, like “reliability” (see “Safe Is Not An Option” for how that worked out), or “performance” (compare price of RS25 engine with a Merlin).
But since Elon Musk is optimizing for cost (and forcing others to do the same due to competitive pressure), I feel a little more optimistic about the prospects for space exploration and settlement (as long as idiots like Shelby don’t force SpaceX to endure micromanagement by NASA).
Ms Starr is on twitter (@riding_red)…. she doesn’t look like any engineer I’ve met.
It’s not clear that (despite what the site says) @riding_red is really her. I was going to tweet to her, but decided not to.
A link on her twitter account directs back to her cnet profile, pictures of her on both cnet and twitter are of the same person, same weird haircut, same tattoo.
Well, OK, then I should have tweeted her. I guess I still could. But so could anyone, with a link to this post.
They want to maximize weight to thrust ratio? That’s backwards. A big thrust to weight ratio is what’s needed for a booster rocket.
Getting high ISP and high weight to thrust ratio is a piece of cake. The Hall Thrusters have great ISP and a W/T in the 1000s.
Maximize, minimize, no one checks the sign of the second derivative — she probably only checks that the slope is zero at a local optimum that could mathematically be a maximum or a minimum.
You can’t use calculus jargon with non-STEM types. They just goggle.
Slope? Derivative? -Second- Derivative? Local optimum?
“Ferraris are expensive, too, but at least they don’t throw the car away each time they take it for a drive.”
Um, depends on whom you trust with the keys . . . “Flounder, you (messed) up, you trusted us!
Rand, you said that the author failed to note that the SLS engine is reusable. It’s really not. As any SLS engineer will explain, once it smacks into the ocean and sinks to the bottom, it’s pretty much done.
Maybe a better Ferrari analogy would be packing one with dynamite and using it as a target at the annual Knob Creek machine gun shoot.
once it smacks into the ocean and sinks to the bottom, it’s pretty much done.
Is that the part where it blows everything else out of the water?
I didn’t even read the article until now. I just saw a blurb about it this morning in the sidebar at Ace of Spades, and that was enough to elicit a facepalm.
Sir, I am a man from the middle east and I am wondering how to gain the power of the white race, can you please help me in this endeavor?
Sure it’s off topic, and your probably just a racist troll, but this thread is already OT and my computer is busy compiling, so I’ll bite.
_____________________________
Follow these three strange steps and your culture can be successful and powerful.
1: Rule of law. (equality under the law, and due process)
2: Cheap Available Resources. (energy, labor, food and minerals)
3: Freedom (the usual bill of rights and ownership of innovation and property)
Your society will become stable, your poor will become wealthy, and a strong middle class will power a dynamic powerful culture.
And thus, you too can learn the ways of the mysterious white people.
This propaganda piece appears in CNet, but par for the course for them. Not exactly an advocacy rag, I’d say the agenda (narrative if you prefer) is technology promotion irrespective of viability. Remember all those great “bubble memory” articles there from the 80s and 90s? Links off the article refer to NASA’s “Mars Rocket” as well. Those who know better realize SLS is no such thing.
I posted it in the Space Show thread earlier, but the original NASA PAO story was a bit more fantasy. Instead of the Ferrari of engines, PAO called it the “Clark Kent” of engines.
Of course, the real sad news isn’t the silly names, but that NASA is touting the test of a SSME as if it was a new development in the building of SLS.
Like the only saying goes: “Right, Fast or Cheap. Pick any two.” This will let us know if NASA can still do at least one of them.
AFAIK, the only rocket to blow another out of the water is the Trident. But, a Sea Dragon would be cool, too.
OT: Thanks for fixing the Amazon search box. I’ve done most of my purchases for the month, but I still have some MP3 albums to buy.
Thanks for using it!
Your Amazon search would get more use if you had a Canadian variant – for Amazon.ca. But I suppose there’s only a couple of us on here so doubt it affects your revenue much.
There are around 15 (maybe 16, if they can cobble one together from an incomplete parts set) RS-25D (SSME) in existence. NASA is assuming that it can restore all of them without any hardware losses (such as a failed turbopump or a RUD on the test stand) and equip them to run with the new engine controllers, etc.
The SLS block 1 will use (and destroy) 4 engines per flight. That means the cuttent supply will last, at best, 4 flights.
Make more SSME? Not really an option; we lost that capability decades ago. So, the “answer” is the RE-25E – an “improved” SSME that’s cheaper. It’s supposedly going to have better performance (in both T/W and ISP) than the SSME. In fact, the SLS performance figures depend upon it doing so.
The RS-25E has a small drawback; it does not exist. It doesn’t even exist on paper yet, because the design has not been finalized.
Theoretically, new manufacturing tech will allow the RS-25E to be better T/W than the SSME. Theoretically. As for ISP improvements, I’m rather dubious.
What I’m most dubious about is the cost per unit of the RS-25E. Like everything else about SLS, I think it’ll cost far more than forecast and have less performance than promised.
I do believe SLS will be a viable Mars rocket, anytime and every time that Mars’ orbit brings it within cislunar space.
4 flights is 2 to 3 years of operation at the pathetically slow flight rate.
@ Leyland
Yes, 4 flights is 2 to 3 years at a pathetically slow flight rate. However, at SLS’s projected flight rate (one flight every two years… 3 years minimum between the first two launches alone), it’s about 8 years (more likely a decade or more IMHO).
SLS would need to more than double its flight rate to achieve pathetically slow. If we set the fiscal issues (such as insane cost) aside, the SLS flight rate could be increased (provided we set the existence of its post-SSME main engines aside too, and launch with power-point engines instead of metal ones)
🙂
You are right. I flipped the numbers. Probably because as bad as 2 flights a year sounds, it doesn’t sound as pointless and stupid as 1 flight every 2 years.
They had 14 RS-25’S and 2 ground test unit used for qualification testing. They were able to build two more RS-25’s using available spare parts. I’m assuming they didn’t consume their entire spare part inventory to do this but this being a gov’t organization I can’t promise that level of common sense. So, yes they have just enough engines for only 4 launches. In a Reddit AMA the RS-25 engineers did said that they are exploring the use of additive 3d printing to build many or not most of the parts for the new RS-25’s. So, that way they don’t have to rebuild all the necessary tooling equipment.
One of the things I shook my head at when I was reading a SpaceFlightNow article about the RS-25 engine test was that they were testing an ablative coating applied to the OUTSIDE of the engines. Apparently, when you put something between two massive solid rocket boosters they found out it gets kinda hot in around that environment and they needed an ablative coating to keep the engines from melting. Well, gee willikers who could imagine?
Apparently, NASA is trying to sweep the whole reusability thing, with regard to the RS-25, under the rug. A group of RS-25 engineers, including Kathryn Crowe, did an AMA on Reddit last week. When one person asked, “How much of the SLS is reusable?”, Steve Wofford replied,
Yes, that is right, they view throwing the rocket engine away as a good thing; because it will save them money not having to rebuild it.
Oh and of course it being Reddit we find out what their favorite pizza is. Ronnie Rigney says he doesn’t even like pizza…….What kind of heathens do they employ over there at NASA?
A space port on a 12 mile high tower!
SLS the graft that keeps on grifting…