NASA's Kepler space telescope discovered thousands of planets outside our solar system, and revealed that our galaxy contains more planets than stars. Credit: CNASAredit: NASA Ames/JPL-Caltech
On the evening of Thursday, Nov. 15, NASA's Kepler space telescope received its final set of commands to disconnect communications with Earth. The "goodnight" commands finalize the spacecraft's transition into retirement, which began on Oct. 30 with NASA's announcement that Kepler had run out of fuel and could no longer conduct science.
Coincidentally, Kepler's "goodnight" falls on the same date as the 388-year anniversary of the death of its namesake, German astronomer Johannes Kepler, who discovered the laws of planetary motion and passed away on Nov. 15, 1630.
The Kepler space telescope has had a profound impact on our understanding of the number of worlds that exist beyond our solar system. Through its survey, we've discovered there are more planets than stars in our galaxy. As a farewell to the spacecraft, we asked some of people closest to Kepler to reflect on what Kepler has meant to them and its finding of "more planets than stars."
The final commands were sent over NASA's Deep Space Network from Kepler's operations center at the Laboratory for Atmospheric and Space Physics, or LASP, at the University of Colorado in Boulder. LASP runs the spacecraft's operations on behalf of NASA and Ball Aerospace & Technologies Corporation in Boulder, Colorado.
Kepler's team disabled the safety modes that could inadvertently turn systems back on, and severed communications by shutting down the transmitters. Because the spacecraft is slowly spinning, the Kepler team had to carefully time the commands so that instructions would reach the spacecraft during periods of viable communication. The team will monitor the spacecraft to ensure that the commands were successful. The spacecraft is now drifting in a safe orbit around the Sun, 94 million miles away from Earth.
The data Kepler collected over the course of more than nine years in operation will be mined for exciting discoveries for many years to come.
NASA's Ames Research Center in California's Silicon Valley manages the Kepler and K2 missions for NASA's Science Mission Directorate. NASA's Jet Propulsion Laboratory in Pasadena, California, managed Kepler mission development. Ball Aerospace & Technologies Corporation operates the flight system with support from LASP.