LOS ANGELES (AP) — An international satellite rocketed into low-Earth orbit Friday on a mission to track changes in the amount of salt in the upper levels of the world's oceans.
A Delta 2 rocket carrying the Argentine-built satellite blasted off shortly before 7:30 a.m. under cloudy skies at Vandenberg Air Force on the Central California coast.
The rocket and its international payload roared southwestward over the Pacific, quickly vanishing into a deep marine layer that typically shrouds the state this time of year.
Ground controllers cheered and clapped after the satellite with a NASA instrument on board was boosted into orbit and unfurled its solar panels about an hour after liftoff. Early communications with the satellite indicated it was healthy.
Michael Freilich, who heads NASA's Earth science division, was relieved and overjoyed the satellite "is working so well from the beginning."
NASA's Aquarius instrument will measure the concentration of dissolved salt at the sea surface. The amount of brine in the ocean remains fairly constant, but salt levels in the uppermost layer vary around the globe.
NASA will produce monthly maps detailing sea salt changes during the three-year mission. Scientists hope the data will help them better predict future climate change and short-term climate phenomena such as El Nino and La Nina.
For decades, ocean salinity has been charted the old-fashioned way — by ships and buoys. The problem with that is there are gaps in the data since researchers don't have surveys for many parts of the ocean.
Besides Aquarius, seven other instruments will collect environmental data including a camera that will make images of volcanic eruptions, wildfires and urban light.
The $400 million mission is a cooperation between NASA and Argentina's space agency CONAE. Other countries participating in the project include Brazil, Canada, France and Italy.
"It was worth the effort," CONAE executive Conrado Varotto said at a televised post-launch news conference.
Over the next month, the satellite's orbit will be tweaked until it is some 400 miles above the Earth. Engineers will check the instruments before science operations can begin.
Aquarius joins a European satellite that has been gathering data on both sea salt and soil moisture since 2009. Unlike the European mission, Aquarius will focus only on the ocean.
The launch was the first of five that United Launch Alliance, the joint venture of rocket builders Lockheed Martin Corp. and Boeing Co., will carry out for NASA this year.
The other NASA missions that will ride aboard ULA rockets include the Juno spacecraft to Jupiter, the Grail probe to the moon, the NPP environmental satellite and the Mars Science Laboratory to the Martian surface.
Mission information: http://aquarius.nasa.gov/
Alicia Chang can be followed at: http://twitter.com/SciWriAlicia