Contact re-established with Jupiter probe Juice after a monthAfter losing all communications with Europe’s probe Juice on July 16th, on its way to Jupiter, engineers have finally re-established communications and found the spacecraft to be in sound condition.
Six attempts to steer the medium-gain antenna back towards Earth were unsuccessful. Recovery efforts continued overnight, lasting almost 20 hours and focusing on manually powering up Juice’s onboard communication systems.
Eventually, a command succeeded in reaching Juice and triggering a response. The command activated the signal amplifier that boosts the strength of the signal that Juice sends towards Earth. Contact was re-established, and Juice was found to be in excellent condition. No systems had failed, and all telemetry was nominal.
The root cause was traced to a software timing bug. The software function that switches the signal amplifier on and off relies on an internal timer. This timer is constantly counting up and restarts from zero once every 16 months. If the function happens to be using the timer at the exact moment it restarts, the amplifier remains switched off, and Juice’s signal is too weak to detect from Earth.
The spacecraft has a scheduled fly-by of Venus on August 31st, so regaining contact was critical. It has already done one Earth fly-by, with two more scheduled, before it arrives in Jupiter orbiter in July 2031.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon or from any other book seller. If you want an autographed copy the price is $60 for the hardback and $45 for the paperback, plus $8 shipping for each. Go here for purchasing details. The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
After losing all communications with Europe’s probe Juice on July 16th, on its way to Jupiter, engineers have finally re-established communications and found the spacecraft to be in sound condition.
Six attempts to steer the medium-gain antenna back towards Earth were unsuccessful. Recovery efforts continued overnight, lasting almost 20 hours and focusing on manually powering up Juice’s onboard communication systems.
Eventually, a command succeeded in reaching Juice and triggering a response. The command activated the signal amplifier that boosts the strength of the signal that Juice sends towards Earth. Contact was re-established, and Juice was found to be in excellent condition. No systems had failed, and all telemetry was nominal.
The root cause was traced to a software timing bug. The software function that switches the signal amplifier on and off relies on an internal timer. This timer is constantly counting up and restarts from zero once every 16 months. If the function happens to be using the timer at the exact moment it restarts, the amplifier remains switched off, and Juice’s signal is too weak to detect from Earth.
The spacecraft has a scheduled fly-by of Venus on August 31st, so regaining contact was critical. It has already done one Earth fly-by, with two more scheduled, before it arrives in Jupiter orbiter in July 2031.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon or from any other book seller. If you want an autographed copy the price is $60 for the hardback and $45 for the paperback, plus $8 shipping for each. Go here for purchasing details. The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
“If the function happens to be using the timer at the exact moment it restarts, the amplifier remains switched off”
That’s not a bug, it’s a feature.
– Standard coder response