Nicola Fox is the Associate Administrator for the Science Mission Directorate beginning February 27, 2023.1 Recent Associate Administrators for the SMD include Edward J. Weiler (1998–2004, 2008–2011), Mary L. Cleave (2004–2005), Alan Stern (2007–2008), John M. Grunsfeld (2012–2016), and Thomas Zurbuchen (2016-2022). Stern resigned 25 March 2008, to be effective 11 April, over disagreements with Administrator Michael D. Griffin.2
NASA names solar physicist as agency's science chief https://www.reuters.com/lifestyle/science/nasa-name-first-woman-agencys-science-chief-sources-say-2023-02-27/ ↩
Andrew Lawler, "NASA's Stern Quits Over Mars Exploration Plans" (subscription required), Science 320, 31 (4 April 2008). Retrieved on 3 April 2008. http://www.sciencemag.org/cgi/content/full/320/5872/31 ↩