2009 is a special year in ISS history. Long-awaited permanent crew of 6 is working on-board. Achieving permanent 6 crew is such a major milestone that all symbolism of the patch is built upon number 6.

The central element of the patch is inspired by a fractal of six. The concept of the fractal is "self-similarity". It is symbolically representative of team work as a crew: basic element - a crew member - is in a way similar to the others, but together six of them form a much more complex and multifaceted entity with infinite capabilities. Fractal is related to space because you can go to infinity looking at a fractal at different scales, like in the universe.

The contour shape has 6 tips. Smoothly flowing into each other the shape is geometrically sound and at the same time reminds of a leaf. It represents symmetry and ecological harmony.

Three sections represent: children on Earth in bright Sun - our future and reason why we explore and invest into the future. The Sun has 7 rays - number of luck and happiness which transcends cultures. In order to succeed in future human space exploration today we fly Soyuz and Shuttle to the ISS in low Earth orbit; our next goals are Moon and Mars.

Moon in "young" as a symbol is potential growth. Six stars in deep space represent the current crew and possible later exploration crew.

The Expedition 21 patch was designed by Frank de Winne's wife Lena.

Frank de Winne during training on February 18, 2009, in Houston.

A souvenir version that was available in February 2009.