California-based non-profit B612 Foundation has announced its intention to place an asteroid-hunting infrared telescope into orbit around the Sun. Named Sentinel, the ambitious endeavor is to be the world's first privately funded deep space mission and will aim to map up to 90 percent of all asteroids larger than 140 meters (459 ft) in Earth’s region of the solar system. In addition to these sizable asteroids, Sentinel will further provide data on a number of smaller asteroids, down to a size of approximately 30 meters (98 ft) in diameter.
The Sentinel Space Telescope will take approximately four years to build and test, and the B612 Foundation expects a launch sometime in 2017-18 with the aid of a Falcon 9 rocket. It will then travel through space and make use of Venus's gravity to slingshot into solar orbit and revolve around the Sun every seven months while mapping asteroids within the solar system. Approximately five and a half years of mapping should provide enough data to project the paths of asteroids for around the next 100 years or so and, crucially, give decades notice of any large asteroid on a collision course with Earth.

Sentinel will measure 7 m (25.4 ft) tall x 3.2 m (10.5 ft) across and will weigh 1,500 kg (3,300 Ibs). The space telescope will also contain 96 GB of on-board storage and will be designed to be highly autonomous, requiring only once-weekly ground contact.
http://b612foundation.org/media/sentinelmission/