Ball Aerospace & Technologies Corp. said it signed a contract of unspecified value to build prototype infrared imaging sensors for an asteroid-hunting space telescope called Sentinel that the nonprofit B612 Foundation plans to launch later this decade to scan the skies for space rocks on a collision course with Earth.

Ball is the only contractor for Sentinel and will build both the spacecraft and its sensors. Sentinel is slated to launch in 2017 or 2018 aboard a Space Exploration Technologies Corp. Falcon 9 rocket. The telescope will be placed into a Venus-like orbit for its six-and-a-half-year mission to map the inner solar system and sniff out potentially dangerous asteroids, according an Oct. 30 press release from Boulder, Colo.-based Ball.

Ball has experience with infrared telescopes having built the spacecraft for NASA’s Wide-field Infrared Survey Explorer. The $320 milion mission, launched in 2009 and concluded in 2011, surveyed the entire night sky using a 40-centimeter-diameter telescope built by the Space Dynamics Laboratory in Logan, Utah.

The B612 Foundation, founded in 2002, is a group of scientists whose chairman and chief executive is former astronaut Ed Lu. The project manager for Sentinel is Harold Reitsema, Ball’s former director of science mission development. The foundation unveiled the Sentinel telescope concept in June and announced plans then to give Ball a fixed-price contract to build the observatory.

While it has not provided an exact figure, the B612 Foundation’s website says the Sentinel mission will cost several hundred million dollars.