The majority of space exploration has occurred in Low Earth Orbit, around 120 miles above sea level. For a cool $20 million, any person can take a ride on the International Space Station, around the 1,100 mile band around Earth. Commercial prospects for LEO are huge, there are big dangers lurking for anyone interested in traveling this way, such as radiation, , cosmic rays, and space debris numbering in the thousands threaten any spacecraft traveling in orbit. It's a new frontier and maybe the final frontier, and the possibilities are endless if you are willing to travel to the edge of space exploration.

• Neil deGrasse Tyson
• Erik Thompson
• Alex Filippenko

• David Brin
• David Ackroyd
• Michio Kaku