A U.S. spacecraft on its way to Pluto will be flying close enough to Jupiter in the next few months to study its moons, stormy atmosphere and powerful magnetic field, according to NASA.

Scientists at NASA and Johns Hopkins Applied Physics Lab have aimed the New Horizons spacecraft close to Jupiter to take advantage of the massive gas giant's gravity to "slingshot" it at even faster speeds toward Pluto.

An image of Jupiter, taken Jan. 8 with the New Horizons long range imager while the spacecraft was about 81 million kilometres from the planet, shows the volcanic moon Io to the right. (NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute)

It will make its closest pass by Jupiter on February 28. Jupiter's gravity will accelerate the probe an additional 14,000 km/h, pushing it past 84,000 km/h on its way toward the frigid dwarf planet on the edge of the solar system.

The spacecraft launched on January 19, 2006, and is expected to reach Pluto in 2015.

"Since launch, New Horizons will reach Jupiter faster than any of NASA's previous spacecraft and begin a year of extraordinary planetary science to complement future exploration activities," said Jim Green, acting director of the planetary science division of NASA, on Thursday.

Scientists hope New Horizons will conduct a range of experiments and take countless images of Jupiter and its moons. The planned observations from January through June include scans of Jupiter's turbulent, stormy atmosphere, a detailed survey of its ring system and a detailed study of its moons, including the volcanic Io, and Europa, a moon thought to contain liquid water beneath its icy surface.

"Our highest priority is to get the spacecraft safely through the gravity assist and on its way to Pluto," said New Horizons principal investigator Alan Stern, of the Southwest Research Institute in Boulder, Colorado.

The pass by Jupiter is also providing scientists with an opportunity to test out New Horizons before it gets to Pluto, Stern said.

New Horizons also will take the first trip by a spacecraft down the long "tail" of Jupiter's magnetosphere, a wide stream of charged particles that extends all the way into Saturn's orbital path. It will also take the first close-up look at the Little Red Spot, a new storm south of the more famous Great Red Spot.

Most of the data will not be sent to Earth until after the February 28 flyby, NASA said.