News : NASA's New Horizons mission to Pluto

Date: 2015-07-25 09:39:05

NASA's New Horizons mission to Pluto

After travelling nine years and almost 5.3 billion kilometres, NASA's New Horizons spacecraft will have just one day up close with dwarf planet Pluto and its five moons.

Crucial to the mission is an Australian team operating the giant antennas that will track New Horizons at the moment it comes closest to its target, on Tuesday at 9.50pm.

That seems enough pressure to make even the calmest operator a little edgy, but their leader is confident all will go well.

"We're not nervous because we've rehearsed this quite a few times," said Ed Kruzins​, the CSIRO director of the Canberra Deep Space Network, which operates four communications dishes on behalf of NASA.

On Tuesday evening, the space probe will make its closest approach to Pluto, about 12,500 kilometres away, travelling at 58,000km/h â€“ 100 times the speed of a rifle bullet.

"It will pass quickly, which is why we have to get it right here on Earth," said Dr Kruzins. "There will not be another shot."

As Earth spins, the powerful yet highly sensitive dishes at Tidbinbilla will be in the perfect position facing Pluto for Tuesday's approach.

"At closest approach we'll be the station carrying all the data, the imagery and Pluto's atmospheric measurements," he said.

Piloting the Australian antennas will be five operators, known as team C, who will ensure the connection with New Horizons' satellite keeps the stream of data flowing smoothly on the night.

It takes more than 4½ hours for data to travel one way from Pluto to Earth and, given the 4.8 billion kilometres between the two planets, the signal is nothing more than a whisper from space.

Despite its speed, New Horizons, which is about the size of a big fridge with an antenna on its side, has taken almost nine years to reach Pluto.

"We've been to every other planet bar Pluto. This is Captain Cook stuff," Dr Kruzins said.

The probe isn't carrying enough fuel to slow down and orbit the dwarf planet, so instead will fly past it, and its moon Charon, and head for the Kuiper​ belt, a region beyond the planets that is thought to contain lots of icy moons.

Although the mission is only a fly-by, it promises to reveal many insights into a distant region of the solar system.

"If you think of the solar system, it has three key parts to it: the inner rocky planets like Earth and Mars, then the gas giants; the third part, which we know little about, are these icy moons, of which Pluto is the first one," Dr Kruzins said.

It is hoped data from New Horizons will reveal the role these icy moons had in the formation of the early solar system.