who served as acting director the Earth Sciences Division at NASA’s Goddard Space Flight Center from 2011 until his death. Sellers first came to NASA as a scientist in 1986. Ten years later he entered the astronaut corps. Between 2002 and 2010 he made three trips aboard the International Space Station and the space shuttle, contributing to research projects and assisting with the construction of the ISS during a total of six space walks. Sellers also served as project scientist on Terra. As a climate scientist, his Simple Biosphere Model was the first to realistically simulate the interaction of global photosynthesis and Earth’s climate. Sellers appears in actor Leonardo DiCaprio’s film Before the Flood, in which he expresses his optimism about the ability of humankind to make the changes necessary for a ‘safer future’.