The International Space Year (ISY) was 1992, the year of the quincentenary of Christopher Columbus's voyage to the Americas in 1492. First proposed by U.S. Senator Spark Matsunaga, the designation of 1992 as International Space Year was endorsed by 18 national and international space agencies, who also proposed the year's theme, "Mission to Planet Earth". Eventually, 29 national space agencies and 10 international organizations took part in coordinated activities to promote space exploration and the use of sustainable technology on Earth. United Nations endorsement The United Nations Committee on the Peaceful Uses of Outer Space agreed to recognize the International Space Year to promote peaceful cooperation between nations during its 1990 session. United Nations Secretary-General Boutros Boutros-Ghali, addressing the World Space Congress in Washington, D.C., on August 28, 1992, said, "One of the central goals of International Space year is to highlight the importance of understanding the Earth as a single, complex, interdependent system and to stress the unique role that space science and technology can play in promoting that understanding." Given that the year 1992 marked the anniversary of 500 years of genocide around the world, it is important to note the UN Working Group on Indigenous Populations requested the United Nations recognize 1992 as the International Year of the World's Indigenous People. However, the colonial nations of the Americas and Spain blocked the request as they had plans to celebrate the Quincentenary of Columbus' voyage. The United States featured a poster celebrating 1992 as the International Space Year in which, as described by the Smithsonian National Air and Space Museum: "Movie character 'ET' embraces earth; on horizon shows progression of exploring vehicles from [C]olumbus' ships to present." It celebrates Columbus' voyage, indicating the Columbian legacy was viewed as an inspiration for the future of space travel. Global activities International Space Year was celebrated by 29 space agencies in various countries with the purpose of establishing peaceful international relations in space programs. International Space Year conferences were held regularly in many nations. Australia In Australia, many public events were organized to augment public awareness of space by the National Space Society chapters of Australia. CSIRO led the "Mission to Planet Earth" Land Cover Change project, using satellites to study plant life on Earth in relation to climate and civilization. CSIRO and various Australian Universities also studied the ocean using European and Japanese satellites. Additionally, a series of commemorative stamps