put telescopes back in their places
I have one of the best jobs in the world, helping manage NASA’s exoplanet-hunting Kepler Space Telescope. In 2012 and 2013, the craft lost two of the four gyroscope-like reaction wheels it uses to balance itself. Without at least three of them, it would tumble off into space. We managed to stabilize it by firing its chemical thrusters, but the telescope was still moving too much to make steady observations.
To give it new life, NASA began what is now the K2 mission. One of the project’s engineers, Doug Wiemer, suggested Kepler could balance on its remaining two wheels if the sun’s photons were pushing it at just the right spot, like a kayak pointing directly upstream. We spent months trying to find the perfect orientation. The trial run went five times better than we could have hoped— and that was our first try! Four years later, we’ve found another 307 exoplanets. When Kepler runs out of fuel in a few months, it will have done its job—twice.