Aiming ahead: next generation visions for the next 50 years in space

The year 2007 has been a very important one for space; it marked the 50th anniversary of the Space Age. Such a moment calls for a reflection on the past and a review of accomplishments to date, but moreover, it calls for a planning of the future, which may take humanity to places that past generations could only dream about. Throughout the last half of the century, humanity has achieved great advances in many different areas. Technological endeavour has been accompanied by a tremendous social, cultural and economic impact. Space activities have entered an era where a mixture of various disciplines from sciences to humanities will be necessary for future space exploration enterprises. This raises the question of what will happen next? Or rather, what should happen next?