No longer the exclusive domain of government entities such as NASA and other national agencies, space exploration is rapidly becoming privatized, with entrepreneurial startups building huge rocket boosters, satellites, rocket engines, asteroid probes, prospecting craft, and even commercial lunar cargo landers to open this new frontier. Research into ever more sophisticated propulsion and life support systems will soon enable the journey to Mars and destinations deeper in our solar system. As these technologies continue to move forward, there are virtually no limits to human spaceflight and robotic exploration.