Space education is important part of science education but not appropriate enough for students with special needs (SSN). This project is aimed to generate and adapt some materials and methods to close the this gap. At the beginning of the project we classified topics from the space education/cosmology and prepared some braille documents, videos, materials and assessment tools. By this project we intend to prepare a Massive Online Open Course (MOOC) about basic concepts of cosmology for SSN. This MOOC project is different from others in terms of two reasons; Participants will use 3D materials and become peer educators for their friends. In other words, new participants should be friends of previous participants. This is why we used “tree” for the name of project. During the project, some branches of the MOOC will be rich according to the some participants whose social abilities are strong and unfortunately some branches will be poor due to characteristics of participants or other unknown reasons. The content of this project will be in two language at the beginning; English and Turkish.