Spacecraft gets up close with Pluto

MUMBAI: World space history took a giant leap on Tuesday when Nasa's piano-sized New Horizons spacecraft, with a suite of seven instruments, became the first mission globally to make the closest approach to the dwarf planet Pluto at 5.20 pm (IST) zipping across at a whopping velocity of 14 km/second.

It was the first mission to Pluto, making the US the only nation in the world to visit all the planets. John Grunsfield, Nasa associate administrator, declared, "This is true exploration. Pluto has turned out to be an interesting and complex world."

Mission operations manager, Alice Bowman, said that the much-awaited fly by occurred 72 seconds earlier than planned, and the spacecraft was 7,750 miles (12,472 km) above the surface of Pluto.

The fly by took place exactly 50 years after Nasa's Mariner 4 did a fly by of Mars on July 14, 1965.

More than nine years after its la8unch, the spacecraft capped in 4.88 billion-km journey to the solar system's farthest reaches, Nasa said. The craft flew by the distant "dwarf" planet after reaching a region beyond Neptune called the Kuiper Belt that was discovered in 1992.

New Horizons threaded a celestial needle by zooming through a target circle to accomplish its science objectives.

About 30 specific scientific objectives have been planned for Pluto and its moon, Charon, from surface and composition mapping to atmospheric studies and search for new moons and rings. There is also a student experiment known as the Student Dust Counter.

Launched on January 19, 2006, by the Atlas V-551 rocket, and with a Jupiter gravity assist on February 28,2007, New Horizons suffered hiccup on July 4, 2015, when it fell silent.

But a while later it revived and the problem was attributed to computer overload. Mission's principal investigator Alan Stern said that the spacecraft's nuclear power source was supplying 202 watts of power which will steadily decline in the years ahead. According to the present estimate it can operate till about 2030 flying into regions beyond the outer limits of the solar system.

Specifically he said that it will continue to transmit scientific data till October-November 2016. "There will be 16 months of waterfall. If we had not launched in January 2016, then the encounter would have taken place only in 2019," he said.