The B612 Foundation announced the first privately Funded Deep Space Mission yesterday morning. It's called Sentinel, a half-meter infrared telescope designed to look for any asteroids whose orbits will cross the Earth's in the next hundred years, down to thirty meters in size. Construction is expected to begin this fall, and the nearly complete design will be similar to the already-successful Spitzer and Kepler telescopes, albeit slightly smaller. It's still 1 1/2 tons and 25 feet tall. The prime contractor will be Ball Aerospace, contractor for Spitzer and Kepler.

The B612 Foundation unofficially began in 2001. Astrophysicist Piet Hut and former astronaut Ed Lu held a 2001 workshop on Near-Earth Asteroids in Houston. The workshop attendees concluded that something needed to be done as soon as possible to be sure that the Earth was not on the verge of being knocked clean. Asteroids have wiped out almost all life on Earth more than once.

An asteroid impacting the Earth does so at a speed so high that the explosion can often be larger than a thermonuclear weapon. Requiring only a few seconds to hit the ground after entering the atmosphere, a large one could liquefy the Earth's crust at the impact point, creating a droplet that ascends into the atmosphere atop spreading circles of liquified Earth. The heat created sets the air on fire and sends a wave of flame hundreds or thousands of miles, leaving nothing alive in its path.

Earlier this month, a kilometer-wide asteroid named 2012-LZ1 flew near the Earth's system just four days after it was discovered. That asteroid was never a threat, but there was insufficient time to react effectively. Had 2012-LZ1 impacted the Earth, it would have wiped out much of humanity.

One big problem is that no comprehensive effort like Sentinel has ever been made to map every Near-Earth Asteroid. Asteroid velocities are tens of thousands of miles per hour, so by the time we spot one we've not previously detected, it's generally too near for us to do anything but calculate its orbit and wipe our foreheads. Even a common and relatively modest asteroid like the one that hit Tunguska, a rural area in central Siberia impacted in 1908, would probably kill tens of thousands of people today at best. The Tunguska asteroid has been estimated at approximately 30 meters, but it released about a thousand times the energy of Hiroshima.

NASA's Wide-field Infrared Survey Explorer (WISE) found over 33,500 of the largest asteroids and comets in the solar system before it was decommissioned in February of 2011. But despite the additions by WISE and ground-based efforts, including most of the planet killers, the majority of the smaller asteroids remain. According to the Foundation's website, "The orbits of the inner solar system where Earth lies are populated with a half million asteroids larger than the one that struck Tunguska in 1908, and the vast majority are uncharted." If one hit near a heavily populated area, it might kill hundreds of millions of people.

After the meeting in Houston, the problem seemed urgent enough to warrant the dedication of the scientists' lives. As former astronaut Rusty Schweikart put it, "Let's get on with it."

Hut, Lu, Schweikart, and another attendee, astrophysicist Clark Chapman, formed B612 to organize an effort to map all of the asteroids that cross the Earth's orbit. The Foundation is named after the Prince's home in "The Little Prince".

Several years were spent attempting to organize other groups and individuals to accumulate what was required to map the solar system. In a FAQ on the organization's website, the Foundation says it became evident that the effort wasn't working, and there seemed to be ample evidence that private citizens could organize to design and launch their own spacecraft. The design of Sentinel began then, with Foundation members working alongside other scientists and engineers, several of whom had designed other space telescopes. They chose an orbit well away from the Earth. Data will be relayed to NASA's Deep Space Network and distributed to several locations for analysis.

According to the same FAQ, "The optimal location for tracking Near Earth Asteroids, and for making the Sentinel Map, is from a location between the Earth and the Sun, from where a space telescope can scan Earth’s orbit while continuously looking away from the Sun." Accordingly, B612 began planning possible ways to get the spacecraft into a long elliptical orbit near Venus (orbit pictured above) with SpaceX. This month, they signed a Space Act Agreement with NASA to support the project.

The funding, a few hundred million dollars, isn't quite there yet, but the Foundation feels confident that it will be soon. As their website has pointed out, larger amounts of money have been raised for other non-profit efforts "such as museums, performing arts centers, and academic buildings."

When the spacecraft is ready it will probably go up aboard a SpaceX Falcon 9. Alongside the data that arrives from Planetary Resources' constellation of telescopes around the Earth, we may at least know what we're up against in the next decade, with (hopefully) a decade or more of warning before any asteroid that poses a real danger.

B612 Foundation has a good video and plenty of other material describing the mission on their home page.