# Have Kagome lattice patterns been used as structural reinforcement in spacecraft in non-Iranian spacecraft? Can we help Scott Manley "unsee" this one?

Scott Manley's January 2, 2022 video Iran's Reinvigorated Space Program Makes Final Rocket Launch of 2021 references this tweet and screenshots it in his video,

I am a bit surprised this is a legal design in Iran... no offence meant, I just cannot unsee.

and says:

We know this one went off on that trajectory because there are images on social media showing locals who found a fairing that had landed near their town.

And I'm going to say, looking at the interior of this, a lot of people saw right away that *the grid pattern that they had etched on to the surface for strength did include the Star of David, and in fact, yeah! You draw lines and it does in fact look like the flag of Israel and I can't unsee that now that it's been pointed out.

Obviously that is there for good structural engineering reasons, but I still can't unsee this thing.

The pattern shows is of course called a Kagome lattice which is a 2D structure sought after by both experimental and theoretical physicists. The pattern of two concentric equilateral triangles (one either flipped or rotated by 60°) is a six-pointed Kagome crest or Shatkona.

On a flat or cylindrical surface the pattern has three sets of parallel lines, call them A, B, and C, but instead of all three intersecting at the same points, they are offset so that AB, BC, and CA intersections are at different points, dividing the surface into twice as many triangles as hexagons.

Question: Have Kagome lattice patterns been used as structural reinforcement in spacecraft in non-Iranian spacecraft? Is this in fact a common pattern? Perhaps a few examples will help Scot in his "unseeing" efforts.

above: Japanese wicker basket with a kagome pattern Source, below: Kagome lattice (Japanese: 籠目) Source

Screenshots from Scott Manley's January 2, 2022 video Iran's Reinvigorated Space Program Makes Final Rocket Launch of 2021

Fourth image (and linked tweet) show lines added to indicate similarity to flag (click for full size):

To a Western audience the six-pointed version of the Kagome crest as religious symbol perhaps most closely resembles the Star of David, however, any direct connection between the two is unlikely. If a cultural connection involving the Kagome crest does exist, it is most likely related to the satkona of Hinduism.

update: More examples of a kagome lattice used as a structural element

above: "Example of a kagome basket. (Credit: Okinawa Institute of Science and Technology)" source: The Electronic Structure of a “Kagome” Material below: Figure 3 from Manufacturing and testing of a CFRC sandwich cylinder with Kagome cores

Based off of a quick read, lattice work in structures have been around for a while and kagome seems to be a popular one, with Russians (and Chinese) using it in some of their rocketry.

That it filters down to other - developing - states is not surprising.

Have Kagome lattice patterns been used as structural reinforcement in spacecraft in non-Iranian spacecraft?

Yes

Is this in fact a common pattern?

Yes

Perhaps a few examples will help Scot in his "unseeing" efforts.

Uh. No idea. I knew someone who was studying mathematical geometrical patterns in nature and seeing familiar patterns such as this that have been used in religious circles was quite common and not terribly wobbly-inducing.

The early research on grille was mainly in the former Soviet Union and the United States, which directly served the military and aerospace. The former Central Research Institute of the Soviet Union (CRISM) started a similar structure research in 1981, and by the end of the research in 1985, the inter-stage structure of the rocket was prepared by the continuous filament winding method. Later, the grid inter-stage structure of the launch vehicle (1988) and the spaceship attachment adapter of the grid structure (1999) were successively developed.

The grid structure is now widely used in the Russian heavy launch vehicle Proton-M. The payload attachment (docking box) is the primary structure of the launch vehicle - connecting the rocket and the spacecraft. Due to the different diameters of the rocket and the spacecraft, the typical docking frame is a conical configuration. The grid adapter of Proton-M is shown, the butt frame of the grid structure is 60% lighter than the aluminum structure and saves 30% of the cost.

http://www.yhclgy.com/html/2017/1/20170102.htm

http://yatakviju.mirtesen.ru/blog/43083075833/Osnova-dlya-buduschih-raket-Rossii----sverhlyogkiy--kompozitnyiy?utm_referrer=mirtesen.ru

https://cordis.europa.eu/docs/results/265881/final1-2014-03-06-alasca-final-report-submitted.pdf

Deriving from a spacecraft well proven structure design, two different pro‐lattice barrel concepts has been developed.

https://www.satorsrl.it/grid-structures/

Not sure if this counts:

https://fhclxb.buaa.edu.cn/article/doi/10.13801/j.cnki.fhclxb.20210107.002?pageType=en

Chinese article seems to have an interesting nose cone:

Satellites:

Unsure if these are just designs or have been implemented in reality:

https://123ru.net/pics/21870588/