Astronomy Now Home
Home Magazine Resources Store

On Sale Now!

The October 2014 issue of Astronomy Now is on sale! Order direct from our store (free 1st class post & to UK addresses). Astronomy Now is the only astronomy magazine specially designed to be read on tablets and phones. Download the app from Google Play Store or the Apple App Store.

Top Stories

Earthshine used to test life detection method
...By imagining the Earth as an exoplanet, scientists observing our planet's reflected light on the Moon with ESO's Very Large Telescope have demonstrated a way to detect life on other worlds...

Solid buckyballs discovered in space
...Astronomers using NASA’s Spitzer Space Telescope have detected a particular type of molecule, given the nickname “buckyball”, in a solid form for the first time...

Steamy water-world gets the Hubble treatment
...Hubble Space Telescope observations of a 7 Earth-mass planet find an unusual water-rich world swathed in a thick, steamy atmosphere...

Juno spacecraft recovers from fault after Earth flyby

Posted: 14 October 2013

Scientists in charge of NASA's Jupiter-bound Juno mission said Friday the speedy spacecraft recovered from a fault that triggered an unexpected safe mode as it zoomed by Earth for a gravity assist flyby Wednesday.

Artist's concept of Juno flying past Earth. Credit: NASA/JPL
"The spacecraft is currently operating normally and all systems are fully functional," the Southwest Research Institute in San Antonio, the home institution for Juno's science team, said in a statement.

Juno exited safe mode at 5:12 p.m. EDT (2112 GMT) Friday, according to SWRI.

Racing away from Earth after a slingshot maneuver to gain speed, Juno is on the way to an encounter with Jupiter on July 4, 2016, to begin a one-year investigation of the giant planet's magnetic field, atmosphere and internal dynamo.

Wednesday's flyby of Earth was planned before Juno's launch in August 2011 because its launch vehicle was not powerful enough to send the spacecraft on a direct journey to Jupiter.

The Earth flyby increased Juno's velocity by more than 16,000 mph, bending its trajectory to carry the probe out to Jupiter's orbit for arrival in less than three years.

Juno's closest approach to Earth, about 350 miles over the Indian Ocean near South Africa, occurred when the spacecraft was out of range of ground stations. But when a European Space Agency antenna in Australia picked up a signal from Juno a few minutes later, controllers noticed the spacecraft put itself in an automated fault-protection status known as safe mode.

In safe mode, the spacecraft deactivated its science instruments and turned toward the sun to ensure its batteries remained charged.

Officials said most of the images and data expected from the flyby were collected and downlinked to Earth before Juno initiated safe mode.

This processed image from Juno's camera, provided by a user known as AstroO and posted on the Juno mission website, shows South America with clouds covering Patagonia. Credit: NASA/JPL/SWRI/MSSS
Juno's science instruments were supposed to measure charged particles and plasma in the Earth's magnetosphere, observe the auroras, and look at the Earth and moon with infrared and ultraviolet instruments.

Scott Bolton, Juno's principal investigator from SWRI, said the $1.1 billion mission's science team planned to use data gathered during the flyby for calibration of the craft's instruments and as a simulation for mission operations once Juno reaches Jupiter.

The spacecraft's main camera, named JunoCam, also took pictures of Earth during the flyby. Raw images from JunoCam are available online for processing by amateurs and enthusiasts, making the camera an outreach tool for public relations and education.

And Juno acquired images during approach for scientists to stitch together into a movie of the Earth and moon, showing the moon circling the planet in an unprecedented vista from deep space, Bolton said.

"It will be very different from anything any human has ever seen before," Bolton said.

The Planets
From tiny Mercury to distant Neptune and Pluto, The Planets profiles each of the Solar System's members in depth, featuring the latest imagery from space missions. The tallest mountains, the deepest canyons, the strongest winds, raging atmospheric storms, terrain studded with craters and vast worlds of ice are just some of the sights you'll see on this 100-page tour of the planets.

Hubble Reborn
Hubble Reborn takes the reader on a journey through the Universe with spectacular full-colour pictures of galaxies, nebulae, planets and stars as seen through Hubble's eyes, along the way telling the dramatic story of the space telescope, including interviews with key scientists and astronauts.

3D Universe
Witness the most awesome sights of the Universe as they were meant to be seen in this 100-page extravaganza of planets, galaxies and star-scapes, all in 3D!


© 2014 Pole Star Publications Ltd.