Kepler shut down for ten days to save the mission.Uh-oh: Kepler has been shut down for ten days to save the mission.
The spacecraft was launched with four so-called reaction wheels that spin to help keep the telescope pointing at its target fields of stars. One of these, reaction wheel No 2, failed in July 2012, leaving three to do the maneuvers, including a quarterly roll to a new orientation. Now reaction wheel No 4 has shown early indications that it might fail, prompting its NASA controllers to attempt some long-distance maintenance. They hope that by resting the wheels, their lubricant will spread to ease increased friction.
If this wheel fails permanently, the Kepler mission would be over, as it would be impossible to orient the spacecraft with enough precision with only two wheels.
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. from any other book seller, or direct from my ebook publisher, ebookit.
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
Uh-oh: Kepler has been shut down for ten days to save the mission.
The spacecraft was launched with four so-called reaction wheels that spin to help keep the telescope pointing at its target fields of stars. One of these, reaction wheel No 2, failed in July 2012, leaving three to do the maneuvers, including a quarterly roll to a new orientation. Now reaction wheel No 4 has shown early indications that it might fail, prompting its NASA controllers to attempt some long-distance maintenance. They hope that by resting the wheels, their lubricant will spread to ease increased friction.
If this wheel fails permanently, the Kepler mission would be over, as it would be impossible to orient the spacecraft with enough precision with only two wheels.
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. from any other book seller, or direct from my ebook publisher, ebookit. 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
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