Long-time NASA employee Ed Weiler has been named permanent director of the agency's US$5-billion science division, returning to a position he held between 1998 and 2004.

Weiler, an astrophysicist, replaces Alan Stern, a planetary scientist who resigned in March after a dust-up with NASA chief Michael Griffin over the Mars exploration budget. Weiler himself is no stranger to such arguments; in 2004, he and Sean O'Keefe, NASA's then head, had differing views on whether a robotic servicing mission to the Hubble Space Telescope was a good idea. Later that year, Weiler took over directorship of NASA's Goddard Space Flight Center in Greenbelt, Maryland.

In general, Stern was praised by space scientists for his desire to boost launch rates and research funding. He also enforced a strict accountability for mission cost overruns (see Nature 448, 978; 2007), which ruffled some feathers, especially within the Mars community.