Mug made in celebration of ESA’s ‘Principia’ mission to the International Space Station 15 December 2015 to 18 June 2016.

Among the variety of technical topics outside of Stephen Hawking's scientific expertise that make a presence in his office, the most prominent is spaceflight. Hawking was a very abstract theoretician, but his two most important scientific predictions depended heavily on astronomical observations that could only be conducted outside the Earth's atmosphere. Less than a decade after his dissertation, a NASA x-ray satellite detected the first signal strongly suspected to be a black hole. Through the 1970s and 1980s, rockets and satellites reached into space to measure and image the cosmic microwave background radiation, and continued to improve this map to compare with models of the Big Bang including those proposed by Hawking. Stephen championed space exploration as fundamental to the future of the human species and had public opinions on topics such as the Search for Extraterrestrial Intellicence. Since the 2000s, Stephen also saw the possibility of visiting outer space within his lifetime and was courted by a variety of agencies, entrepreneurs and celebrities advocating for human spaceflight.