Engineers hope Juno’s Earth flyby yesterday will help solve a mystery seen in previous flybys by unmanned probes.
The uncertainty of science: Engineers hope Juno’s Earth flyby yesterday will help solve a mystery seen in previous flybys by unmanned probes.
Since 1990, mission controllers at ESA and NASA have noticed that their spacecraft sometimes experience a strange variation in the amount of orbital energy they pick up from Earth during flybys, a technique routinely used to fling satellites deep into our Solar System. The unexplained variation is noticed as a tiny difference in the expected speed gained (or lost) during the passage.
The variations are extremely small: NASA’s Jupiter probe ended up just 3.9 mm/s faster than expected when it swung past Earth in December 1990. The largest variation– a boost of 13.0 mm/s – was seen with NASA’s NEAR asteroid craft in January 1998. Conversely, the differences during swingbys of NASA’s Cassini in 1999 and Messenger in 2005 were so small that they could not be confirmed.
The experts are stumped.
It is likely that these small variations are related in some way with simple engineering and not some unknown feature of gravity. Nonetheless, it remains a mystery.
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
The uncertainty of science: Engineers hope Juno’s Earth flyby yesterday will help solve a mystery seen in previous flybys by unmanned probes.
Since 1990, mission controllers at ESA and NASA have noticed that their spacecraft sometimes experience a strange variation in the amount of orbital energy they pick up from Earth during flybys, a technique routinely used to fling satellites deep into our Solar System. The unexplained variation is noticed as a tiny difference in the expected speed gained (or lost) during the passage.
The variations are extremely small: NASA’s Jupiter probe ended up just 3.9 mm/s faster than expected when it swung past Earth in December 1990. The largest variation– a boost of 13.0 mm/s – was seen with NASA’s NEAR asteroid craft in January 1998. Conversely, the differences during swingbys of NASA’s Cassini in 1999 and Messenger in 2005 were so small that they could not be confirmed.
The experts are stumped.
It is likely that these small variations are related in some way with simple engineering and not some unknown feature of gravity. Nonetheless, it remains a mystery.
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
Well, I actually solved the problem. Here is my press release concerning the flyby -> http://www.prlog.org/12219228-juno-earth-flyby-anomaly-calculated.html
And here I was just thinking it could be the variations in the Earths surface.
As a craft moves past the Earth if it passes over the Himalayas the surface would be closer to the craft than if it passed by over the open flat ocean.
More mass miles closer to the craft causes an increase in the working gravity.
Pzatchok,
The gravitational variations in the density and elevations of the Earth are well mapped and included in orbit equations. These variations are even used to routinely change orbital planes ( e.g. so that a spacecraft can be constantly in sunshine — called a sun-synchronous orbit).
My first thought was that the lunar influences were miscalculated (a three-body equation has been elusive), but that seemed rather unlikely, given the large number of accurate calculations given by the many orbital calculators.
Although I do not understand how spacecraft spin affects orbital mechanics, Kimmo Rouvari’s hypothesis/theory seems more plausible than anything I can think of (such as influence by “space aliens” who are just messing with our minds).
Unfairly, I am making these comments without having read Rouvari’s “Theory of Everything by illusion,” perhaps because it just seems illusory to me (pun intended — in fact, the whole reason for this sentence was to make that pun — I hope you take this with amusement, Kimmo).
No problem Edward! I have a great sense of humour :-) Besides, you have plenty of time to read my paper after the flyby results are public. My kind advice… sit while you read ;-)
Units should be mm/s, my bad!
Here’s latest regarding Juno Earth flyby http://www.prlog.org/12232145-juno-earth-flyby-anomaly-calculated-update.html
1.111 mm/s at perigee! Champagne is ready to go ;-)