Satellites monitor the Earth’s weather and are responsible for the vast majority of the accuracy of weather forecasts. A satellite-aided search and rescue system ensures immediate detection of an alert anywhere in the world, and aids the rescue of thousands of people each year. The International Charter 'Space and Major Disasters' provides charitable and humanitarian acquisition of satellite data from over 60 spacecraft to aid relief efforts in major disasters. In 2013 an American high school launched the first spacecraft designed, built, and operated by high school students.