Grid-stiffened cylinders for space transportation

Grid stiffened structures are a type of carbon-fibre reinforced polymer structure that is created by arranging multiple ribs in a lattice (see image on right). This type of configuration allows structures to be built with a very high specific strength and stiffness, which could mean huge mass savings if it can be used in a launcher inter-stage. An activity with GSTP and ATG EUROPE B.V. in the Netherlands has begun to prepare the building blocks which will lead to manufacturing several latticestructure interstages using this method.

The activity was split into two phases. First, during a preliminary phase, the activity aimed to ensure all necessary manufacturing items and knowledge were available in time for the follow-on activity, where the actual manufacturing of a number of inter-stages would be performed.
The final design of the cylinder weighs approximately 87.5kg and uses 5 skin plies across the full cylinder length. Depending on the progress in a follow-up phase, this could possibly be reduced by a further 10-15%, mostly by reducing the amount of skin covering the surface. This would however result in much lower margins for the Failure Index. This does prove that further development of grid-stiffened technology for launcher (inter-stage) applications such as this will achieve further launcher mass reductions. The realised reductions can eventually be converted into increased launcher performance.

In total over 130 silicone plates were produced which are planned to be waterjet cut into approximately 4000 cell blocks in the follow-on project. This, together with the 500 specially shaped blocks manufactured with the 3D printed tooling, will be used to complete the manufacturing of the cylinders in the follow-up phase.

GT17-137TIbl closed in 2021