In the other hand, radiation environment in space is very unique and complex and has three components including:galactic cosmic radiation (GCR), solar particle events (SPE)and trapped energetic particles (TEP). The high LET/charge/energy particles such as protons and Helium from GCR can cause more complex biological effects. In addition to cardiovascular,CNS, hematopoietic and many other diseases, recent evidence show, GCR leads to cognitive impairment and increased Ab plaque accumulation and so Alzheimer’s disease