The land controller has sent the final command to NASA's Kepler telescope, turned off the spacecraft transmitter and deactivated the automatic recovery software of the tool maker after the planet-hunting observatory ran out of fuel last month.
The last signal for Kepler was broadcast from the control center at the Atmospheric and Space Physics Laboratory, or LASP, at the University of Colorado at Boulder, through NASA's Deep Space Network on Thursday night.
Engineers ordered Kepler to turn off radio transmitters, standard procedures during the deactivation of space missions to ensure false signals do not interfere with communication using the same or similar frequencies. The order also prevents the computer on the Kepler ship from trying to revive the transmitter and contact Earth.
"Because the spacecraft is slowly spinning, the Kepler team must be careful about timing orders so instructions will reach the spacecraft during a period of proper communication," NASA said in Friday's update. "The team will monitor the spacecraft to ensure that the order is successful."
NASA announced October 30 that Kepler is running out of fuel and no longer has the stability to look for planets around other stars.
Launched in 2009, Kepler circled the sun around 94 million miles (151 million kilometers) from Earth. On its current path, Kepler flies a little farther from the sun than Earth, and circulates around the sun a little slower than Earth.
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The spacecraft will be farther away from Earth over the next few decades, before finally the Earth begins to rise again. By 2060, Kepler will return to around the Earth – but far beyond the moon's orbit – and planetary gravity will pull the telescope into orbit a little closer to the sun, and that moves faster than Earth.
The opposite will occur in 2117, when Kepler and Earth meet again and gravity pushes the spacecraft into a orbit that is farther and slower. This pattern is predicted to continue for the future, according to NASA.
Meanwhile, scientists continued to analyze data collected during the nine-year Kepler mission, $ 692 million.
Kepler collected his latest scientific observations in September, ending a journey that observed more than 530,000 stars and returned 678 gigabytes of data. Kepler's findings also helped astronomers write nearly 3,000 scientific papers, a number that will continue to increase.
Astronomers using data collected by Kepler confirm the existence of 2,681 planets orbiting other stars, with 2,899 other planet candidates in the pipeline that can be confirmed by further observations.
"We found small, potentially rocky planets around these bright stars, and they are now the main target of telescopes today and in the future so we can continue to see what these planets are made of, how they are formed, and how their atmosphere is like, "said Jessie Dotson, Kepler project scientist at Ames.
"Even though we have stopped spacecraft operations, the science results from Kepler's data will continue for years to come," he said.
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