The high-energy solar particle detector, which was positioned on board the satellite with seven other probing facilities, will collect data on the space expanse between 40,000 kilometers and 400,000 kilometers from earth to moon, said Li Chunlai, chief designer of the ground application system of the lunar probe.

    The information it gathers will enable scientists to learn about the environment and ensure the safety of future spacecrafts, Li said, adding that a payload data processing system has also been activated, but other equipments remain "dormant" to save energy.

    Emergency measures have also been designed to handle any hitch to the payload equipments, including placing spare parts and circuits in key equipments, Li said.

    The 2,300-kg satellite has just completed its first orbital transfer around 5:57 p.m. Thursday afternoon, a step further in its 380,000-km journey to the moon.

    Chang'e-1 needs to conduct ten orbit maneuvers during its flight, and is expected to enter earth-moon transfer orbit on Oct.31 and arrive in the moon's orbit on Nov. 5. It will relay the first pictures of the moon in late November and will then continue scientific explorations of the moon for a year.

    Chang'e-1, named after a mythical Chinese goddess who, according to legend, flew to the moon, blasted off on a Long March3A carrier rocket at 6:05 p.m. on Wednesday from the Xichang Satellite Launch Center in the southwestern province of Sichuan.

    It carried eight probing facilities, including a stereo camera and interferometer, an imager and gamma/x-ray spectrometer, a laser altimeter, a microwave detector, a high-energy solar particle detector and a low-energy ion detector.

    Its major scientific objectives include a three-dimensional survey of the moon's surface, analysis of distribution and amounts of elements on the lunar surface, an investigation of the characteristics of lunar mantle rock and the powdery soil layer on the surface, and an exploration of the environment between the Earth and the Moon.