[meteorite-list] Juno Spacecraft Recovers From Fault After Earth Flyby

[Ron Baalke]

http://www.spaceflightnow.com/juno/131013update/ 

Juno spacecraft recovers from fault after Earth flyby
BY STEPHEN CLARK
SPACEFLIGHT NOW
October 13, 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.
 
"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.

[Image]
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.