$1 billion Aqua satellite will watch the water

Our watery world will undergo more scrutiny

(CNN) -- If all goes as planned, NASA will launch a spacecraft named Aqua into orbit Saturday morning carrying six different instruments designed to study the Earth's water cycle.

"Aqua will observe our Earth's oceans, atmosphere, land, ice and snow covers and vegetation," said Claire Parkinson of NASA's Goddard Space Flight Center.

"This comprehensive approach enables scientists to study the interactions among key elements of the Earth system so as to better understand our planet."

Studying how oceans, clouds and rain affect the Earth's ecosystems should help scientists better understand the dynamics of global climate change, mission researchers said.

During its six-year mission, Aqua will circle the Earth about once a day about 438 miles above the planet.

The nearly $1 billion orbiter is the sister satellite to Terra, a NASA spacecraft launched in 1999 that also studies global environmental change.

In recent years, NASA has launched several other satellites to monitor hydrological and other natural cycles on the planet, including Jason I and the twin GRACE satellites.

The 10-minute launch window for the Delta II rocket that will carry Aqua into space from Vandenberg Air Force Base, California will open Saturday at 5:54 a.m. EDT.