One of NASA’s most popular and successful missions has hit a disabling technical snag, the agency announced Wednesday. A reaction wheel on the Kepler spacecraft has become stuck, say NASA engineers. Without it, scientists can’t aim the telescope as precisely as they need to.

The Kepler space observatory was launched on March 6, 2009 on a search to disprove the notion that Earth is unique in the universe. Over four years, Kepler found more than 100 planets orbiting distant stars. In April, Kepler scientists announced they had found two planets roughly Earth-sized and in the so-called “Goldilocks zone” where liquid water may flow on the surface.

The artist's concept depicts NASA's Kepler misssion's smallest habitable zone planet. (Credit: NASA Ames)
The artist’s concept depicts NASA’s Kepler misssion’s smallest habitable zone planet. (Credit: NASA Ames)

Kepler, which is based at NASA Ames, near Mountain View, has special significance to Bay Area scientists, including Geoffrey Marcy, a professor of astronomy at UC Berkeley and a co-investigator on the Kepler project. Reached in his office today, Marcy told me Kepler’s failure has had him in tears.

How are you?


So it’s as bad as it sounds?

Yeah. We knew the friction in Reaction Wheel Four was getting worse and worse. It was [moving] in a sort of hurk-jerky motion. And that’s a tell-tale sign of failure

Is there really nothing that can be done to fix it?

The party line is “there are many things to try right now.” Engineers at NASA Ames are going to try and start up the reaction wheel, rock it back and forth – like when your car is stuck in the snow — forward, backwards, hoping it gets unstuck. So there’s hope, but not much.

You know, the spacecraft got its four year nominal mission. That’s all that was expected. But we were hoping for another four years.

What’s this like for you?

I feel awful. I feel dizzy and my eyes are tearing up.

You know, it feels funny to to speak emotionally about a telescope, but in the last 2,400 years, since the time of the ancient Greek philosophers, people have wondered whether there were other Earth-like planets. Kepler is the mission that answered that question. We found Earth-like planets by the hundreds. And now this beautiful instrument has died.

It’s a loss for our species. That sounds dramatic, but we pride ourselves as a species of exploration, seeking answers beyond the horizon, answers about our place in the universe. And Kepler was answering those questions.

This artist's concept depicts a small planetary system around a red dwarf. Credit: NASA Ames
This artist’s concept depicts a small planetary system around a red dwarf. Credit: NASA Ames

What did Kepler find?

We now have a very strong measurement of how common Earth-sized planets are, and how many might be habitable. We wanted another two-to-four years to pin it down. We’re left with a good answer, but it’s not as secure of an answer as we had hoped.

We’ve found hundreds of Earth-sized- planets. But not a single planet that’s definitely like the Earth: rocky surface, liquid water, lukewarm temperature, suitable for biochemistry of life. We haven’t really identified, yet, an Earth-twin planet where we would say “yeah, that one looks like home.”

There is still a lot of Kepler data yet to be processed, right?

Yes, and we’re going to be working nonstop. I’m working seven days a week, evenings; my grad students are working non-stop. We have a team here that uses the Keck telescope in Hawaii to measurer the properties of these planets – their orbits, what their atmospheres might be like. So we still have to answer those questions for the planets we’ve found.

Could it be that the mythical Earth-twin planet is still in the data, waiting to be uncovered?

Absolutely. And we’re going to work even harder now that the data is even more precious. And we’re gonna try to search for intelligent signs of life on those planets, too.

Intelligent life? Tell me more.

I have funding [from the Templeton Foundation] for a search to look for laser beam transmissions from advanced civilizations. It’s a crazy project and I’m nearly sure I’ll fail. But I have to try.

The idea is you would use lasers to send a message from one civilization to another one on another planet. You can’t stream cable; fiberoptics don’t work over millions of miles. If alien civilizations are communicating with each other in some kinds of great galactic internet, maybe we can read their email.

Kepler Scientist: “A Beautiful Instrument Has Died” 17 May,2013Amy Standen


Amy Standen

Amy Standen (@amystanden) is co-host of #TheLeapPodcast (subscribe on iTunes or Stitcher!) and host of KQED and PBSDigital Studios’ science video series, Deep Look.  Her science radio stories appear on KQED and NPR.

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