NASA's Kepler spacecraft hurtled past the moon's orbit last night, three days into the first leg of its six-year mission to find other Earth-like planets.
The spacecraft, which is carrying a telescope and a series of computers, now is about 250,000 miles from Earth, according to James Fanson, the Kepler program manager. The craft is expected to drift away from the Earth at a rate of 10 million miles per year.
The new telescope was launched months after a computer failure onboard the orbiting Hubble Space Telescope forced NASA to postpone a planned October launch of the space shuttle Atlantis, which was set to do scheduled repairs to Hubble.
NASA engineers first fixed the Hubble's problem by using an online backup system. Two glitches quickly derailed that NASA repair effort. The computer was finally fixed a month later and the Hubble telescope was back in business, snapping pictures of a pair of gravitationally interacting galaxies.
Right now, according to Fanson, Kepler is moving at a rate of 5 miles per second.
"We are just at the beginning of what will be two months of calibrations and testing," Fanson told Computerworld. "It will take a while before planet discoveries are made. After several months, we should start to see large planets. And in two to three years, we'll start to see planets that are more the size of Earth."
A protective cover is expected to be popped off the telescope in about three weeks, and then Kepler will take its first images.
The Delta II rocket carried the planet-hunting spacecraft aloft at 10:49 p.m. EST last Friday from Cape Canaveral Air Force Station in Florida. The Kepler spacecraft is designed to study between 100,000 and 170,000 sunlike stars and find Earth-like planets that may orbit them. Fanson explained that the telescope onboard the spacecraft will measure the brightness of those stars every half hour, allowing scientists to detect any dimming in their brightness caused by orbiting planets passing in front of them.
Based on the dimming of a star's light, Fanson said they should be able to calculate the size of an orbiting planet, along with whether it has a solid surface and if there's the potential for it to have liquid water, which scientists say is crucial to the formation of life.
"It has a telescope, but it's not generating pretty pictures," said Fanson. "What we'll bring down are pixels around target stars, marking the brightness of each of these 170,000 stars."
While the spacecraft is in its initial setup mode, NASA scientists and engineers will be in contact with it 24 hours a day. When the craft moves into scientific mode, NASA will be in communication with Kepler ever four days, and once a month the ground will turn the spacecraft so its antenna points toward Earth so data can be transmitted down.