Heavy lift. Super heavy

Until I saws this graphic I did not realize the size of the SpaceX rocket they’re trying to launch today. The problem, as explained countless times, is the more fuel you include, the heavier it is. The heavier it is, the more fuel you need. Repeat endlessly.

At lift off it will produce twice the thrust of any previous rocket, or, if useless comparisons are your thing, the equivalent of 100 Concorde jets taking off simultaneously.

Launch site in Texas, path over the Caribbean, because what could be in the way under that?

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I remember seeing a documentary on the moon race that said the designer of the Saturn V was really designing for a trip to Mars, not just the moon. So unless SpaceX is trying to carry a much larger payload, seems to be reinventing the wheel.

They needed to reinvent the wheel, because we can’t build a Saturn V anymore. Most of the engineering material has been lost over the years, and the engineers died of old age. There was one, complete, Saturn V, sitting outside of a museum. Several years ago, a team started trying to reverse engineer it. They may be able to duplicate it, but they will never know why the engineers in the 60s designed it the way they did.

To put the Saturn V in perspective, I remember this pic of von Braun in his office, with a V2 second from left on the credenza, and a Saturn V, built to the same scale, on the other end.

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Launch scrubbed for today. Evidently a pressurant valve not working correctly.

  • Pete

Here’s a video on trying to make the Saturn V’s first stage engines again after all these years.

Bottom line - exactly what you said. Not enough surviving drawings, too many designers no longer with us.

–Peter <== who watched a great many manned launches while his father was at work in case he was needed to rerun some numbers

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So how many half giraffes with gas would that be?

Cheers
Qazulight

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Half giraffes are really inefficient. Depending on which half you have (left, right, front, rear) you get a lot of off-axis thrust, which requires quite a bit of rudder input, increasing drag. Adding a lot of those together, you can get so much off-axis thrust that you can’t compensate with the rudder and the whole thing spins out of control. Much better to use full giraffes instead of half giraffes.

I’ve ignored the top/bottom halves, as they are generally useless. Top halves lack any thrust at all. Bottom halves have the same thrust as a full giraffe, but have no guidance system.

–Peter

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The guy in the video is the first I have ever heard claim NASA has all the drawings for a Saturn V, or even for the first stage engines. American companies and agencies are pretty bad about keeping obsolete records. Ever watch the DVD supplements to “U-571”? The producers went to both the USN and German Navy for technical assistance. Unfortunately, the story called for the US sub to be a 1920s vintage S-Class boat, rather than a Gato class sub, of which several have been preserved as museums. All the USN could provide was a handful of interior photographs. The German Navy, on the other hand, provided a full set of drawings of the required model of U-Boat.

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It’s been a while since I watched that video. You are quite right. He does claim the drawings exist. I was wrong on that front.

–Peter

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That should not be true. I worked for Pratt in the 90s. The record keeping was extreme. The specialty materials were chemically and process wise well documented for future development.

Rocket theory is well discussed among those who want to study it.

In the case of the Saturn V, we are talking about products that have been out of production for 50 years. Some of the vendors have been taken over, repeatedly. Rocketdyne, builder of the F-1 engine started as part of North American, which became part of Rockwell, which was bought by Boeing. Boeing sold it to United Technologies, which sold it to GenCorp, which merged it with Aerojet. Are all the F-1 records, even in digitized form (and who is going to scan E size drawings for decades out of production parts?) going to be moved, repeatedly? Storing stuff costs money. That hurts “shareholder value”.

Some vendors have gone out of business. When Packard closed in Detroit, in 1956, tons of documents were wheeled across the street to the power plant, and burned in the boilers, even though the Studebaker division was still running in South Bend. When Chrysler took over American Motors all the inventory of parts for AMC/Rambler vehicles were tossed in a landfill. I bet the same happened to records from any Saturn V vendors that closed.

Steve

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The “new thing” here isn’t just related to size/payload, it is mainly that most of the parts are reusable. At this point, it would not make sense to build a Saturn V because it would be terribly wasteful.

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We are having an interesting or telling dialog here about what is possible. Nothing is lost. Not exactly. Things move on.

The question is do we retool our manufacturing? Of course we do. We do not build the same product were were building in 1968.

While we outsourced factories we remained a designer society.

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