unable to produce low density structure - Rocket silo resear

[myslivec]

Hello,
I researched Rocket silo, and I can produce rocket fuel and these modules, but not low density structure. I don't know why (it just does not appear in the "e" menu - to produce it either by hand to give a task to factory).

I guess I'm missing some research, but I cannot find which. Only the Rocket silo is listed as pre-requisite.

Any ideas?

Thanks in advance for any help / suggestions

Honza

[Smarty]

Some pictures and the log should help

[myslivec]

Sorry, my bad - it is there, just on the previous row.

My apologies

Jan