Dr. Marlene Grenon was born in Quebec, Canada. She obtained a diploma in space sciences from the International Space University (ISU) in 1998. She graduated from McGill Medical School in 2000 and obtained a Masters' degree from the Scholars in Clinical Science Program of Harvard Medical School along with a post-doctoral fellowship in cardiovascular space medicine and endocrinology from Brigham and Women's Hospital and the Massachusetts Institute of Technology (MIT) in 2004. She then completed training in cardiac surgery at McGill University in 2007, vascular surgery at the University of British Columbia in 2009 and endovascular surgery at the Arizona Heart Institute in 2010. She is a fellow from the Royal College of Physicians and Surgeons of Canada (RCPSC) and maintains a Certificate of Specialist in both cardiac and vascular surgery from RCPSC.

Dr. Grenon is presently an Associate Professor in the Department of Surgery at UCSF, a Staff surgeon at the VAMC San Francisco and an Adjunct Faculty at the International Space University. She is a member of many professional organizations and has been an invited lecturer at several regional, national and international meetings and conferences. She is the recipient of several awards for research and was one of the finalists in the 2009 Canadian Astronaut selection.