There's something wrong with Kepler, the sun-orbiting spacecraft at the center of NASA's mission to identify Earth-like, habitable planets orbiting other stars. And if the space agency's engineers can't fix it, one of the coolest NASA missions, ever, could end before its time.
Last month, Kepler found some extremely promising planets orbiting "habitable zones" of other, sun-like stars — the best candidates yet to host some sort of life. Since 2009, the $600 million mission has identified nearly 3,000 potential Earth-like planets, and confirmed the existence of 132 "habitable zone" planets in the Milky Way. But now, two of the wheels that control the direction in which Kepler points are broken. As deputy project manager Charles Sobeck told the Associated Press, that means NASA "can't point where we need to point. We can't gather data."
Kepler finds new planets by monitoring distant stars for momentary drops in brightness, caused by a planet passing in between the star and Kepler's sophisticated telescope. The amount of light blocked by the planet indicates its size. It's precise work, and without regaining adequate control of the vessel, NASA's mission won't be able to continue.
But NASA isn't abandoning the project, yet. In a statement released Wednesday, the agency gave a rundown of the seemingly dismal, but not hopeless, state of affairs:
We will take the next several days and weeks to assess our options and develop new command products. These options are likely to include steps to attempt to recover wheel functionality and to investigate the utility of a hybrid mode, using both wheels and thrusters.
With the failure of a second reaction wheel, it's unlikely that the spacecraft will be able to return to the high pointing accuracy that enables its high-precision photometry. However, no decision has been made to end data collection.
Because Kepler orbits the sun, and not the Earth, NASA can't just send astronauts out to it for a repair job — it's about 40 million miles away from us right now. So they're trying to figure out if there's a remote way to get the part back into service, or if they can control Kepler using other methods. If they can't, there's a possibility that Kepler's telescope could come in handy for less precise work, according to the AP.
Even if Kepler can't be repaired, NASA wants you to know that they're not done discovering new things in the data collected so far: "Even if data collection were to end," their statement read, "the mission has substantial quantities of data on the ground yet to be fully analyzed, and the string of scientific discoveries is expected to continue for years to come."