Staff writers
The solar-powered Juno spacecraft has successfully fired its thrusters to adjust its flight path for arrival at Jupiter in five months and one day's time.
"This is the first of two trajectory adjustments that fine tune Juno’s orbit around the sun, perfecting our rendezvous with Jupiter on 4 July," said Scott Bolton, Juno principal investigator at the Southwest Research Institute in San Antonio.
NASA reported that Juno spacecraft's thrusters fired for 35 minutes, consumed about 560 grams of fuel, and changed the spacecraft's speed by 31 centimetres per second.
Juno is roughly 684 million kilometres from Earth and 82 million kilometres from Jupiter. It broke the record for the Earth's farthest-flung solar-powered vehicle on 13 January at 793 million kilometres from the Sun.
The previous record-holder was the European Space Agency's Rosetta spacecraft in its 10-year chase after comet 67P/Churyumov-Gerasimenko. Its orbit peaked at 792 million-kilometres from Earth in October 2012.
"Juno is all about pushing the edge of technology to help us learn about our origins," said Bolton.
"We use every known technique to see through Jupiter's clouds and reveal the secrets Jupiter holds of our solar system’s early history. It just seems right that the sun is helping us learn about the origin of Jupiter and the other planets that orbit it."
Juno was launched on 5 August 2011. It is destined to orbit Jupiter 33 times, at its closest just 5,000 kilometres above the planet's cloud tops, probing beneath to learn more about the planet's origins, structure, atmosphere and magnetosphere.
The spacecraft, operating so far from the Sun, is testing the limits of solar power. It carries three nin-metre solar arrays carrying 18,698 individual solar cells made from silicon and gallium arsenide.
On Earth the cells have the potential to generate approximately 14 kilowatts of electricity, but out where Juno is now travelling the produce just 500 watts on Jupiter.
"Jupiter is five times farther from the sun than Earth, and the sunlight that reaches that far out packs 25 times less punch," said Rick Nybakken, Juno's project manager from NASA's Jet Propulsion Laboratory in Pasadena, California.
"While our massive solar arrays will be generating only 500 watts when we are at Jupiter, Juno is very efficiently designed, and it will be more than enough to get the job done."
