This week a spacecraft on a five-year journey will finally arrive at its destination. NASA’s Juno Spacecraft was launched on August 5th, 2011 from Cape Canaveral and will arrive at Jupiter this Monday 4th July at 8:35 PM PDT (Tuesday 5th July, 3:30 PM in New Zealand) to begin studying our Solar System’s largest planet.
Juno is a spinning, solar-powered spacecraft which will be in a highly elliptical polar orbit, allowing it to avoid most of Jupiter’s high-radiation areas. It carries 29 sensors, which feed data to 9 onboard instruments. Eight of these are for science purposes, while JunoCam is aboard to generate images for public and education outreach. JunoCam’s optics were designed to capture high-resolution views of the planet’s poles, allowing the public to come along for the ride to Jupiter.
This mission is one of many firsts, as it will be the first space mission to orbit an outer planet from pole to pole, the first to fly as close as 4,184 km to Jupiter’s cloud tops, and it will be the farthest solar-powered spacecraft from Earth. Jupiter’s orbit is five times farther from the Sun than Earth’s orbit, resulting in the giant planet receiving 25 times less sunlight than Earth. To gather as much solar power as possible, Juno has large surface area solar panels with a solar cell design that uses advanced modern cells. These are 50 percent more efficient and radiation tolerant than the silicon cells that were available for space missions 20 years ago.
Juno carries some special guests on board; the 1.5-inch figurines of Galileo Galilei, the Roman god Jupiter and his wife, Juno. Their inclusion in the spacecraft is part of NASA and the LEGO Group’s joint outreach and educational programme to inspire children to explore science, engineering, technology and mathematics. Galilei made several important discoveries about Jupiter, including the moons that orbit the planet. Juno was said to be able to peer through the clouds, and thus the spacecraft is named after her as it will, for the first time, see below Jupiter’s dense cover of clouds.
The primary motive for the Juno mission is to improve our understanding of the history of our Solar System. Jupiter is made up of mostly hydrogen and helium, meaning it must have developed early, capturing most of the material left from the formation of our Sun. Juno will help reveal and provide insight into the story of the planet’s formation and evolution. The spacecraft will observe the gas giant’s gravity and magnetic fields and atmospheric dynamics and composition. Not only will this improve our knowledge of Jupiter itself, but it will also provide the knowledge to help us understand the origins of planetary systems around other stars.
After the study is complete, Juno will be instructed to plunge into Jupiter’s atmosphere, where it will burn up like a meteor.