Ian Crawford and Charles Cockell report on a wide-ranging RAS Discussion Meeting putting the broad scientific case for people in space, at the Linnean Society on 10 December 2004. Despite the tragedy of the Columbia accident in February 2003, and the resulting hiatus in construction of the International Space Station, the prospects for human space exploration are in many ways brighter than at any time since the Apollo programme in the late 1960s. In January 2004 President Bush announced a new Vision for Space Exploration, which has refocused NASA's objectives towards human missions to the Moon and Mars, and the European Space Agency's Aurora programme has established similar objectives for Europe. At some stage the UK will have to decide whether, and to what extent, to participate in these exciting endeavours. It is clearly important that the scientific issues are carefully examined, which was the primary motivation for this meeting. In addition, the RAS has decided to establish an independent commission, under the chairmanship of Prof. Frank Close, to examine the scientific arguments for and against human spaceflight (see “Human spaceflight review” p1.7). The members of the review commission were present at the meeting, which may therefore be seen as marking the beginning of the evidence gathering phase of the commission's work. While the subject of human space exploration is controversial in the UK, with many scientists believing that the resources would be better invested in robotic missions, it can be argued that human beings are uniquely qualified to undertake key scientific investigations in the space environment. These range from life and physical sciences research in microgravity, to geological and biological fieldwork on planetary surfaces. The meeting covered all these areas, providing a valuable interdisciplinary overview of the scientific case for human space exploration. Many of the talks also addressed some of the wider societal issues that arise in the context of human space activities.