the record

atmosphere

NASA’s Juno mission to Jupiter broketo become humanity’s most distant solar-powered emissary, when the spacecraft reached about 793 million kilometres from the Sun. The previous record-holder was the European Space Agency’s Rosetta spacecraft, whose orbit peaked at 792 million kilometres in 2012, during its approach to comet 67P/Churyumov- Gerasimenko. Juno will arrive at Jupiter on July 4. Over the next year, it will orbit the Jovian world 33 times, skimming to within 5,000 kilometres above the planet’s cloud tops every 14 days.During the flybys, Juno will probe beneath the obscuring cloud cover of Jupiter and study the planet’s aurorae to learn about its origins, structure,and magnetosphere. Launched in 2011, Juno is the first solarpowered spacecraft designed to operate at such a great distance from the Sun. That is why the surface area of solar panels required to generate adequate power is quite large. The four-tonne Juno spacecraft carries three 9-metre-long solar arrays festooned with 18,698 individual solar cells. At Earth distance from the Sun, the cells have the potential to generate approximately 14 kilowatts of electricity.“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 at NASA. “While our massive solar arrays will be generating only 500 watts when we are at Jupiter, Juno is efficiently designed, and it will be more than enough to get the job done,” said Nybakken. Juno’s maximum distance from the Sun during its 16-month science mission will be about 832 million kilometres, an almost five per cent increase in the record for solar-powered space vehicles.