The Space Security Index (SSI) is a tool for policy-makers, space actors and the public which assess the impact of developments related to space upon spacial security. Published annually, SSI is based on two key components: a fact-base of the trends and yearly developments under eight "indicators" of space security based on primary research; and input from space stakeholders including an online survey assessment of space security and set the value of the Space Security Index in each of the eight indicators for that year. The latter consultative process engages a broad cross-section of policy-makers, civil, commercial, and military space experts from many different countries, to facilitate dialogue on space security challenges and potential responses.