Kepler Mission Cannot Be Restored
August 16, 2013

NASA To Abandon Attempts To Fully Recover Kepler Space Telescope

redOrbit Staff & Wire Reports - Your Universe Online

After spending several months attempting to restore the Kepler Space Telescope to full working order, NASA announced on Thursday it was throwing in the towel – though the observatory could continue to function in a somewhat limited capacity.

According to the US space agency, two of Kepler’s four gyroscope-like reaction wheels have failed – one in July 2012 and the other in May. Those wheels are used to precisely direct the spacecraft and engineers had been attempting to restore at least one of them to working condition. Those efforts, however, have proven unsuccessful.

The telescope completed its prime mission in November 2012 and began a four-year extended mission shortly thereafter. However, it needs at least three functioning wheels in order to continue searching for Earth-sized exoplanets (habitable worlds located outside of our solar system).

Now, as NASA officials analyze the data previously collected by the observatory, they are also said to be considering what type of scientific research Kepler can conduct in its current condition. Last week, engineers conducted a system-level performance test on the telescope and found one of the wheels is no longer capable of the type of precision pointing required for data collection.

As a result, the spacecraft was returned to its point rest state, which NASA said is a stable configuration where Kepler uses its thrusters to control its pointing with minimal fuel use. There are plans to conduct an engineering study on the modifications that would be required to manage science operations with the telescope using only its two remaining functional reaction wheels and thrusters for attitude control.

“The Kepler project team will perform a study to identify possible science opportunities for a two-wheel Kepler mission,” the agency explained in a statement. “Depending on the outcome of these studies, which are expected to be completed later this year, NASA will assess the scientific priority of a two-wheel Kepler mission. Such an assessment may include prioritization relative to other NASA astrophysics missions competing for operational funding at the NASA Senior Review board early next year.”

Data collected during the first half of Kepler’s mission has confirmed the existence of 135 exoplanets and identified another 3,500 potential candidates, NASA reported. Experts are continuing to analyze the four years of collected data and they expect they may find hundreds and potentially even thousands of additional discoveries – possibly including the much anticipated discovery of Earth-size planets in the habitable zone of sun-like stars.

“Kepler has made extraordinary discoveries in finding exoplanets including several super-Earths in the habitable zone,” said John Grunsfeld, associate administrator for the NASA Science Mission Directorate. “Knowing that Kepler has successfully collected all the data from its prime mission, I am confident that more amazing discoveries are on the horizon.”

“At the beginning of our mission, no one knew if Earth-size planets were abundant in the galaxy. If they were rare, we might be alone,” added William Borucki, Kepler science principal investigator at NASA's Ames Research Center. “Now at the completion of Kepler observations, the data holds the answer to the question that inspired the mission: Are Earths in the habitable zone of stars like our sun common or rare?”