NASA successfully launched the unmanned probe, New Horizons, on
Thursday afternoon, on a mission to study Pluto, the smallest and
the most remote planet in the solar system.
New Horizons, the first spacecraft to visit Pluto, blasted off
from the Cape Canaveral Air Force Station, Florida, at 2:00 PM EST
(19:00 GMT), after two delays in the past two days.
High winds at the launch pad forced a delay on Tuesday
afternoon, and a power failure at the Maryland laboratory managing
the mission prevented the second try planned on Wednesday
afternoon.
On Wednesday morning, a major power outage blamed on a storm hit
the area of the Johns Hopkins University Applied Physics Laboratory
that operates the probe and manages the mission.
Thursday's successful liftoff was within a launch time frame
ending Jan. 27 that will allow New Horizons to get a boost in its
velocity from Jupiter's gravity field so as to arrive at Pluto as
early as mid-2015. Scientists believe a direct flight to Pluto
would take as much as four more years.
Pluto is the last unexplored planet in the solar system.
Scientists hope the US$7 million exploration mission could increase
their understanding of the formation of the planets.
The piano-sized probe was carried into space by an Atlas V
rocket. It is expected to travel across the entire span of the
solar system at unparalleled speeds of up to 75,000 km per
hour.
The probe, of 454 kg in weight and equipped with seven
scientific instruments, will conduct flyby studies to the icy Pluto
and its large moon Charon. The fast flying New Horizons does not
carry enough fuel to make slowdowns that allow it to enter the
orbit of Pluto.
Since Pluto is too far away from the sun, the probe cannot use
solar energy and will rely on the power from the radioactive decay
of 24 pounds of plutonium pellets it carries.
At the end of its one-way trip, New Horizons will fly beyond
Pluto and Charon to enter the surrounding Kuiper Belt for a
five-year study of the icy and rocky bodies there. The Kuiper Belt
is believed to consist of remainders from the early formation of
the solar system.
(Xinhua News Agency January 20, 2006)
