IKONOS was a commercial Earth observation satellite, and was the first to collect publicly available high-resolution imagery at 1- and 4-meter resolution. It collected multispectral (MS) and panchromatic (PAN) imagery. The capability to observe Earth via space-based telescope has been called "one of the most significant developments in the history of the space age", and IKONOS brought imagery rivaling that of military spy satellites to the commercial market. IKONOS imagery began being sold on 1 January 2000, and the spacecraft was retired in 2015.
