Two former NASA astronauts have given themselves a new mission: To seek out potentially dangerous asteroids so humanity can have enough time to do something about it.

Apollo moon pilot Rusty Schweickart and Shuttle veteran Ed Lu are spearheading a project to build, launch and fly an infrared space telescope devoted to tracking near-Earth asteroids. They hope to launch the observatory, called Sentinel, in 2017.

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The team, which also includes Stanford University’s Scott Hubbard, the former director of NASA’s Ames Research Center, is part of a nonprofit foundation called B612, a name taken from the fictional planet of the main character in “The Little Prince,” by French author and pilot Antoine de Saint-Exupery.

B612 plans to raise the money for the project, estimated at few hundred million dollars, from corporate, private and philanthropic donations. The idea is not without precedent — many of the world’s observatories were built with private dollars — but it would be a first for a space telescope.

Lu said not to look for the project on Kickstarter, though small donations are welcome.

“We want to be as inclusive as possible,” Lu said.

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Depending on how fund-raising goes, the Sentinel telescope should be ready to fly in 2017 or 2018. It would be put into an orbit around the sun, inward of Earth. That would give it a field of view looking out past Earth, enabling it to track approaching asteroids over months.

The idea is to find 90 percent of all the near-Earth asteroids that are roughly 140 meters (about 460 feet) in diameter, and half of the asteroids that are 40 meters (130 feet) across.

Schweickart said it wasn’t a question of if Earth will get hit, but when.

“You don’t want to put off for some future date if you can make a difference now something which relates directly to human lives and public safety. That’s why we’ve taken the initiative,” Schweickart told reporters during a conference call.

“Federal budgets are constrained very severely right now, so given the priorities NASA faces, it’s pretty difficult for them to move ahead beyond the work that they are doing now,” he added.

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NASA, however, will provide engineering, technical and research support.

“Eventually we’re going to have to deflect an asteroid. We know that. Essentially we’re playing cosmic roulette. We fly around the solar system with these other objects and the laws of probability eventually catch up to you,” Lu said.

The foundation is working on a contract with Ball Aerospace to build the wide-angle, infrared observatory. It plans to hire SpaceX for the launch.

Images: Artist rending of Sentinel on the job in orbit; the telescope will be placed between Earth and Venus in orbit around the sun. Credit: B612 Foundation