The most prolific space laboratory designed to probe the universe's immensity in search of Earth-like planets is back for redemption. After all, the $600-million mission has already contributed to the discovery of over 3,800 potential exoplanets by just merely staring out into space, with 960 of them confirmed by scientists of NASA.
The legendary Kepler spacecraft, which abruptly halted its mission last August 15, 2013 after two of its four reaction wheels broke down, is expected to roll again following NASA's approval of the 2014 Senior Review Process, which included the proposed K2 mission by the Kepler team last November 18.
Kepler's wheels are necessary to move the spacecraft and at least three of them are needed to maintain its stability. Each metal wheel spins at about 1,000 to 4,000 revolutions per minute, helping the craft remain focused to the northern field in the Cygnus, Draco and Lyra constellations, which is safely away from the ecliptic, or the path where the Earth passes though, and direct sunlight.
Using its primary instrument called the photometer, the Kepler spacecraft explores alien worlds through its 0.95-meter diameter telescope and watches out for any temporary decrease in a star's brightness that is caused mainly by a planet in transit in front of their parent stars as viewed from Kepler's perspective. The gathered data is then submitted back to Earth for analysis.
With two of the wheels failing, Kepler, aptly named after the proponent of the laws of planetary motion Johannes Kepler, is spinning out of control, prompting the team in charge to temporarily stop the collection of data.
"The approval provides two years of funding for the K2 mission to continue exo-planet discovery, and introduces new scientific observation opportunities to observe notable star clusters, young and old stars, active galaxies and supernovae," wrote Charlie Sobeck, manager of the Kepler Project, in a statement.
With the K2 mission, or the Second Light, Kepler will be equipped with a clever feature that would help the spacecraft manage the sun's radiation pressure and make it more stable. For 75 days, K2 will observe the ecliptic path, with a photometric accuracy of about 300 parts per million, a far-cry from the mere 20 parts per million it held previously.
"Photons of sunlight exert pressure on the spacecraft. If properly positioned, the spacecraft can be balanced against the pressure as much as a pencil can be balanced in your finger," the Kepler team explained in a graphic presentation.
"The team is currently finishing up an end-to-end shakedown of this approach with a full-length campaign (Campaign 0), and is preparing for Campaign 1, the first K2 science observation run, scheduled to begin May 30," Sobeck said.
