Cosmosphere revisited
August 2024, I visited the Cosmosphere in Hutchinson, Kansas, for the first time since autumn of 2019. Previously, I was bowled over, this time I was disappointed.
They still had an original V-1 and V-2, but the history of the space race was gone, most artifacts not to be seen.
There were some things still on display, like a comparison of Korolev and von Braun’s slide rules.
The difference is striking.
Von Braun’s slide rule a 1947 Pickett, Model 3 Deci Log-log vector type, is much wider and somewhat longer than Korolev’s, with clearly labeled C, CI, D, DI, S, ST, T, CF, DF scales, and some kind of square root and cube root scales. Pickett Model 3 also had scales on the reverse side. The only non-numeric symblo marked is a π.
Based on the 1947 date, it’s possible von Braun used this very slide rule when he worked out the technical appendix of Project Mars.
Korolev’s slide rule has only 7 scales on it, all unlabeled. If you look closely, you can see that the top and bottom sides have rulers marked on them. I’m just young enough to have missed a mandatory slide rule class in college, but I believe that using a slide rule as a straightedge was considered gauche. Korolev’s slide rule appears to have been designed for use as a straightedge and/or a rule as well as a calculating instrument.
I think that the scales on Korolev’s slide rule go like this, from top to bottom:
- K
- A
- B
- CI, probably
- C
- D
- L, I’m least sure of this guess.
C and D scales have some marks labeled other than the usual π:
- Something like ρ11 at 2.3 and a bit
- Another something like ρ11 at 6.38 or so.
- Something like ρ1 at 3.49. No clue.
- Looks like C1 at 3.57.
- Maybe another symbol, too blurry to read in my photo, at the left end of the C and D scales.
A and B scales have an “M” at 31.9 .
Apparently these are gauge points, or gauge marks. One ρ11 is seconds of arc per radian, the other the same but for “centesimal systems”. C1 is supposed to be at √(4/π), 1.128. The M is probably 1/π (multiplied by 100).
I have two slide rules, and only one, a Pickett N1010-ES Trig, has anything other than a π marked on it. The Pickett has an R on the C and D scales at 5.73.
Korolev’s slide rule appears to be a ΓOCT 5161-57 ΓOCT 5161-57 is definitely designed with use as a ruler or straightedge. The cursor doesn’t wrap around the slide rule, it is a channel section that clamps on.
The slide rules were on display before the pandemic, but they just weren’t as noticeable because of all the more eye-catching material displayed around them. August, 2024, there just wasn’t much on display.
A Few Rocket Engines
A SpaceX Merlin combustion chamber.
The note on the case says it was used to launch Koreasat-5a, in 2017. That launch was a Falcon 9 block 4 rocket, making the engine a Merlin 1D.
A MA-5/LR-89 kind of stood in a corner. It had a label about being an Atlas engine, but nothing else.
Another engine, without labels or notes was nearby. Turns out it’s a H-1, and in better days, it had some labels.
That was pretty typical for the spaceflight artifacts they had left. No context. Pitiful labeling, randomly scattered about.
As it was, my son was able to see big differences between the Merlin and the MA-5, pointing out that the manifold that injects propellant into the combustion chamber throat cooling tubes is in quite different places. Even with a diminished number of artifacts, the Cosmosphere could have done some educating.