- Associated Press - Thursday, June 28, 2012

LOS ANGELES — Who will protect us from a killer asteroid? A team of former NASA astronauts and scientists are up for the challenge.

In a bold plan unveiled Thursday, the group wants to launch its own space telescope to spot and track small- and mid-sized space rocks capable of wiping out a city or a continent. With that information, they could sound early warnings if a rogue asteroid appeared headed toward our planet.

So far, the idea from the B612 Foundation is on paper only.

Such an effort would cost upward of several hundred million dollars, and the group plans to start fundraising. Behind the nonprofit are a space shuttle astronaut and an Apollo 9 astronaut, as well as non-NASA space specialists.

Asteroids are leftovers from the formation of the solar system some 4.5 billion years ago. Most reside in the asteroid belt between Mars and Jupiter but some get nudged into Earth’s neighborhood.

NASA and a network of astronomers routinely scan the skies for these near-Earth objects. And they’ve found 90 percent of the biggest threats asteroids at least two-thirds of a mile across that are considered major killers. Scientists believe it was a 6-mile-wide asteroid that wiped out the dinosaurs.

But the group thinks more attention should be paid to the estimated half-million smaller asteroids similar in size to the one that exploded over Siberia in 1908 and leveled more than 800 square miles of forest.

“We’re playing cosmic roulette. We’re flying around the solar system with these other objects. The laws of probability eventually catch up to you,” said foundation chairman and former shuttle astronaut Ed Lu.

Added former Apollo 9 astronaut Rusty Schweickart: “The current priority really needs to be toward finding all of those asteroids, which can do real damage if they hit or when they hit. It’s not a matter of if; it’s really a matter of when.”

Since its birth, the Mountain View, Calif.-based B612 Foundation named after the home asteroid of the Earth-visiting prince in French writer Antoine de Saint-Exupery’s “The Little Prince” has focused on finding ways to deflect an incoming asteroid. Ideas studied include sending an intercepting spacecraft and aiming a nuclear bomb, but not one has been tested.

Last year, the group shifted focus to seek out asteroids with a telescope.

It is working with Ball Aerospace & Technologies Corp., which has drawn up a preliminary telescope design. The contractor developed NASA’s Kepler telescope that hunts for exoplanets and built the instruments aboard the Hubble Space Telescope.

Under the proposal, the asteroid-hunting Sentinel Space Telescope will operate for at least 5 1/2 years. It will circle the sun, near the orbit of Venus, or between 30 million to 170 million miles from Earth. Data will be beamed back through NASA’s antenna network as part of a deal with the space agency.

Launch is targeted for 2017 or 2018. The group is angling to fly aboard SpaceX’s Falcon 9 rocket, which made history last month by lifting a cargo capsule to the International Space Station.