Prof. Orzel gave two talks as part of Physics Day at Space Center Houston last week. The Space Center is the museum and education center associated with NASA’s Johnson Space Center, which has been Mission Control for human space missions since the 1960s. The presentations, to school groups from the Houston area and the museum-going public, explained the science behind and connections between space travel, Einstein’s Theory of Relativity and Earthbound navigation using the Global Positioning system.