On October 29, the Missile Defense Agency announced that it had awarded four $20 million contracts to develop space-based sensors for tracking hypersonic and ballistic missiles. Conducted under the Hypersonic and Ballistic Tracking Space Sensor (HBTSS) program, the contract calls for the companies to design a prototype sensor by October 31, 2020. Analysts view space-based systems as important for tracking non-ballistic hypersonic weapons, whose maneuverability and low trajectories complicate detection by line-of-sight terrestrial sensors.