The Aquarius/SAC-D observatory, NASA’s first ever satellite
to study the saltiness of Earth’s oceans, is in excellent health after its
launch early Friday, initial telemetry reports showed.

The international Aquarius/SAC-D mission is launched from NASA’s Space Launch Complex-2 at Vandenberg Air Force Base in the U.S. state of California June 10, 2011. The rocket blasted off the base carrying a satellite that will collect essential ocean surface salinity data needed to link the water cycle and ocean circulation – two major components of the climate system. (Xinhua/NASA)

The observatory rocketed
into space from Vandenberg Air Force Base in California atop a United Launch
Alliance Delta II rocket at 7:20:13 a.m. PDT (10:20:13 a.m. EDT).

Less than 57 minutes
later, the observatory separated from the rocket’s second stage and began
activation procedures, establishing communications with ground controllers and
unfurling its solar arrays, NASA’s Jet Propulsion Laboratory (JPL) said.

During the next 25 days,
the Aquarius/SAC-D service platform will be tested and maneuvered into its final
operational, near-polar orbit 408 miles (657 kilometers) above Earth. Science
operations will begin after the observatory’s instruments are checked out. This
commissioning phase may last up to 65 days, JPL said.

Aquarius will map the
global open ocean once every seven days for at least three years with a
resolution of 93 miles (150 kilometers). The maps will show how ocean surface
salinity changes each month, season and year. Scientists expect to release
preliminary salinity maps later this year.

“Aquarius is a critical
component of our Earth sciences work, and part of the next generation of
space-based instruments that will take our knowledge of our home planet to new
heights,” said NASA Deputy Administrator Lori Garver. “The innovative scientists
and engineers who contributed to this mission are part of the talented team that
will help America win the future and make a positive impact across the globe.”

Aquarius will measure
salinity by sensing thermal microwave emissions from the water’s surface with
three microwave instruments called radiometers. When other environmental factors
are equal, these emissions indicate the saltiness of surface water. A microwave
radar scatterometer instrument will measure ocean waves that affect the
precision of the salinity measurement.

Because salinity levels in
the open ocean vary by only about five parts per thousand, Aquarius will be able
to detect changes as small as approximately two parts per 10,000, equivalent to
about one-eighth of a teaspoon of salt in a gallon of water.

“Data from this mission
will advance our understanding of the ocean and prediction of the global water
cycle,” said Michael Freilich, director of NASA’s Earth Science Division in the
Science Mission Directorate at agency headquarters in Washington. “This mission
demonstrates the power of international collaboration and accurate spaceborne
measurements for science and societal benefit. This would not be possible
without the sustained cooperation of NASA, CONAE and our other partners.”

The Aquarius/SAC-D
(Satellite de Aplicaciones Cientificas) observatory is a collaboration between
NASA and Argentina’s space agency, Comision Nacional de Actividades Espaciales (CONAE).

Aquarius was built by
NASA’s JPL and the Goddard Space Flight Center in Greenbelt, Maryland. NASA’s
Launch Services Program at the Kennedy Space Center in Florida manages the
launch.

JPL will manage Aquarius
through its commissioning phase and archive mission data. Goddard will manage
Aquarius mission operations and process science data. CONAE is providing the
SAC-D spacecraft, optical camera, thermal camera with Canada, microwave
radiometer, sensors from various Argentine institutions and the mission
operations center. France and Italy also are contributing instruments.

VietNamNet/Xinhuanet