Ever since human beings first looked at the lights in the night sky, they have wanted to know what was out there. The renaissance brought many new advances like the telescope which made more precise astronomical observations possible. But the real advances came in the twentieth century. Early experiments with rockets eventually led to the first satellites and the first manned space missions. Soon, mankind would use these machines to walk on the surface of another world. The Space Shuttle program made space travel more routine. Orbiting space stations make scientific experiments possible. And the future brings the promise of commercial space travel and manned missions to Mars and beyond. In this section of Sea and Sky, you can explore the major milestones that led to the development of our manned space programs and learn about the history of space exploration. Click here for a list of credits and sources.