Sentinel: A Space Telescope Program to Create a 100-Year Asteroid Impact Warning

The nonprofit B612 Foundation is building a space observatory called Sentinel. Its goal is to find a much larger number of smaller-scale asteroids than previous ground-based and space-based surveys because of its improved capabilities. Sentinel will be able to detect potentially harmful asteroids that may impact Earth with sufficiently early warning to permit the deflection of the threat. The Sentinel mission will position a 0.5-m infrared telescope in an orbit around the Sun’s interior to the Earth’s orbit and will scan space in the region near the Earth’s orbit for at least 6.5 years. There are an estimated one million asteroids near the Earth that are larger than 40 m that can destroy a city-sized area if they impact the Earth, and only about 10,000 of these have been found to date since smaller-size asteroids are difficult to observe. Sentinel is designed to find over 100,000 near-Earth asteroids per year. The data collected by Sentinel will allow the orbital path of these detected objects to be determined with sufficient accuracy that it will be possible to map the asteroid’s future path for up to 100 years and assess whether there is a potential for an impact with Earth. Sentinel will be built by Ball Aerospace & Technologies Corp. under an innovative contracting approach that enables substantial cost savings. Sentinel will be privately funded by the B612 Foundation with philanthropic support. Launch is planned for 2018.