[1] He is a National Geographic Fellow, and served as the Senior Policy Advisor to the U.S. Chief Technology Officer Megan Smith in the Obama Administration.

[3] In addition, prior to NASA, Hammer was the Chief Data Scientist at the World Resources Institute, where he helped re-launch Global Forest Watch, an open-source project to monitor deforestation.

[7] Hammer was a Fellow at the Berkeley Institute for Data Science, Faculty at Georgetown University, and works with Steve McCormick (former CEO of The Nature Conservancy) on web service infrastructure for environmental information.

[8] Hammer's recent work with satellite imagery has been used to monitor territorial disputes in the South China Sea, the Xinjiang internment camps, and the October 2017 Northern California wildfires.

[11] Hammer subsequently worked as the research assistant to the current Chief Economic Adviser to the Government of India, Arvind Subramanian, and the President of the Center for Global Development, Nancy Birdsall.