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Post by pierre1985 on Jul 23, 2005 15:37:07 GMT -4
At saturn.jpl.nasa.gov/news/press-release-details.cfm?newsID=117 they say: Successful Trajectory Control Maneuver Marks Milestone for Cassini - November 10, 1997 The spacecraft's velocity relative to the sun is at about 26 kilometers per second (about 59,250 miles per hour = 94,800 kilometres per hour. At Nasa they have not calculated earth velocity = 104,000 kilometres per hour Therefore their calculations are completely wrong and then they can’t go to Saturn Cassini flew for 6,7 years 6,7 x 365 x 24 x 59,250 = 3,477,501,000 miles At Nasa they speak of 2,2 billions miles, they miscalculate too much to be able to go to Saturn
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Post by snakeriverrufus on Jul 23, 2005 20:39:36 GMT -4
Just what does the earths velocity matter after a craft takes off
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Post by gdwarf on Jul 23, 2005 20:54:44 GMT -4
26 km/s converted to km/h is not 94 800, it is 93 600, which is about 58 032 mp/h. Which doesn't really matter, becuase the website you cited does not give an average velocity, instead, it gives the velocity after the speed correction, which is very different from it's average velocity, as it has been slowing down for quite some time. We can get it's actual average speed from this website: www.esa.int/SPECIALS/Cassini-Huygens/SEMAO72VQUD_2.html which says it is 16.4 km/s. So, using this new number and assuming approx. 6.5 years we get: 6.5 * 365 * 24 * 60 * 60 * 16.4 = 3 361 737 600 km, or 2 084 277 312 miles, which is almost exactly what NASA claimed it would be.
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Post by twinstead on Jul 23, 2005 21:13:36 GMT -4
which is almost exactly what NASA claimed it would be. Wow. Quite the shocker...
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Post by pierre1985 on Jul 24, 2005 15:36:12 GMT -4
"We can get it's actual average speed from this website: www.esa.int/SPECIALS/Cassini-Huygens/SEMAO72VQUD_2.html which says it is 16.4 km/s. So, using this new number and assuming approx. 6.5 years we get: 6.5 * 365 * 24 * 60 * 60 * 16.4 = 3 361 737 600 km, or 2 084 277 312 miles, which is almost exactly what NASA claimed it would be". Nasa engineers miscalculate. Earth velocity: 104,000 kilometers per hour. Usual velocity to escape from earth gravity: 36,000 kilometers per hour. 104,000 + 36,000 = 140,000 kilometers per hour. 2,200,000,000 : 140,000 : 365 : 24 = 1.8 years! They could go to Saturn in 1.8 years! Why have they slowed down velocity at 59,040 kilometers per hour?
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Post by Data Cable on Jul 24, 2005 16:03:40 GMT -4
Why have they slowed down velocity at 59,040 kilometers per hour? Orbital Mechanics.
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Post by pierre1985 on Jul 24, 2005 16:06:56 GMT -4
"Orbital Mechanics".
Explain, please]
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Post by twinstead on Jul 24, 2005 16:10:22 GMT -4
pierre1985 how many other forums would you expect, even after all your insults and irrational diatribes, to still have the decorum to address your questions calmly and politely?
It's what sets this forum apart from many on the net. Did you even notice?
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Post by pierre1985 on Jul 24, 2005 16:32:46 GMT -4
"Orbital Mechanics"?
Explain, please
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Post by Data Cable on Jul 24, 2005 16:42:19 GMT -4
"Orbital Mechanics"? Explain, please Why does Saturn revolve around the sun more slowly than the earth? Why does Neptune revolve around the sun more slowly than Saturn? If you don't know the answers, why not do a little research on the subject for yourself, and perhaps you will discover the answer on your own.
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Post by pierre1985 on Jul 24, 2005 17:02:04 GMT -4
"Why does Saturn revolve around the sun more slowly than the earth? Why does Neptune revolve around the sun more slowly than Saturn? If you don't know the answers, why not do a little research on the subject for yourself, and perhaps you will discover the answer on your own".
What's that got to do with it?
Close to Saturn Nasa engineers have slowed down their probe at 1,400 miles per hour.
It seems that they are no problem to brake their probes. They use the foot-brake.
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Post by LunarOrbit on Jul 24, 2005 17:22:02 GMT -4
What's that got to do with it? Everything. NASA didn't slow the probe down, the laws of physics did.
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Post by gdwarf on Jul 24, 2005 17:23:33 GMT -4
"We can get it's actual average speed from this website: www.esa.int/SPECIALS/Cassini-Huygens/SEMAO72VQUD_2.html which says it is 16.4 km/s. So, using this new number and assuming approx. 6.5 years we get: 6.5 * 365 * 24 * 60 * 60 * 16.4 = 3 361 737 600 km, or 2 084 277 312 miles, which is almost exactly what NASA claimed it would be". Nasa engineers miscalculate. Earth velocity: 104,000 kilometers per hour. Usual velocity to escape from earth gravity: 36,000 kilometers per hour. 104,000 + 36,000 = 140,000 kilometers per hour. 2,200,000,000 : 140,000 : 365 : 24 = 1.8 years! They could go to Saturn in 1.8 years! Why have they slowed down velocity at 59,040 kilometers per hour? That calculation is overly simplistic, and even if it was accurate one of the reasons the probe is slowing down is due to the Sun's pull on it, the reason these planets orbit the Sun is becuase it has a gravitational pull on them, so as the probe travells it is slowed by the pull from the Sun, it won't be free from this pull untill it leaves the solar system far, far behind. I'm sure that there are other things slowing it down, but that would seem to be a big one. Besides which, your calculation assumes that the Earth is heading directly towards Saturn, and that there is no friction is space and that there is no gravity eminating from the sun. I'm not sure about number one, but the final two are certain, there is friction in space and the Sun is pulling on the probe.
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Post by JayUtah on Jul 24, 2005 19:31:30 GMT -4
What's that got to do with it?
Because the answer to those questions is the answer to Cassini's dynamic behavior. When you understand one, you understand the other. The fact that you don't see the connection between the two is evidence that you have no knowledge of the sciences that govern the motion of spacecraft. And therefore your claims lack foundation.
Close to Saturn Nasa engineers have slowed down their probe at 1,400 miles per hour.
False. You have been told several times to consult the field of orbital mechanics. That is the study of the behavior of bodies whose motion is dominated by momentum and gravity. It is the science behind the navigation of spacecraft.
This and other questions show that you have little correct understanding of orbital mechanics. Until you do, we are not obliged to take your claims at face value. The members of this board are not responsible for your individual education. You have the responsibility to master the sciences that pertain to your argument. Only then do you merit the dignity of a response.
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Post by PeterB on Jul 24, 2005 22:19:14 GMT -4
Pierre How much do you know about how spacecraft move in space? Do you know Kepler's Three Laws of Orbital Motion? Do you know how the speed of an orbiting object changes as it moves through its orbit? When you know the answers to these questions, you can discuss Cassini with us. Hint: aerospacescholars.jsc.nasa.gov/HAS/cirr/ss/2/4.cfm might be an interesting site to visit.
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