Engineers have successfully ejected the dust cover from NASA's Kepler telescope, a spaceborne mission soon to begin searching for worlds like Earth.
Kepler, which launched on March 6 from Cape Canaveral, Fla., will spend three-and-a-half years staring at more than 100,000 stars in our Milky Way galaxy for signs of Earth-size planets. Some of the planets are expected to orbit in a star's "habitable zone," a warm region where water could pool on the surface. The mission's science instrument, called a photometer, contains the largest camera ever flown in space — its 42 charge-coupled devices (CCDs) will detect slight dips in starlight, which occur when planets passing in front of their stars partially block the light from Kepler's view.
The telescope's oval-shaped dust cover, measuring 1.7 meters by 1.3 meters (67 inches by 52 inches), protected the photometer from contamination before and after launch. The dust cover also blocked stray light from entering the telescope during launch — light that could have damaged its sensitive detectors. In addition, the cover was important for calibrating the photometer. Images taken in the dark helped characterize noise coming from the instrument's electronics, and this noise will later be removed from the actual science data. With the cover off, starlight is entering the photometer and being imaged onto its focal plane. Engineers will continue calibrating the instrument using images of stars for another several weeks, after which science observations will begin.
The artist's animation illustrates how the dust cover on NASA's Kepler telescope will be ejected. Engineers will send a command up to the space telescope to pass an electrical current through a "burn wire." The burn wire will break and a latch holding the cover closed will be released. The spring-loaded cover will swing open on a fly-away hinge, before drifting away from the spacecraft and entering its own orbit around the sun. (Kepler is also orbiting the sun in what's called an Earth-trailing orbit. (Image credit: NASA/Ames/JPL-Caltech)
