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Passer a pas passer par.
RCAF Col Jeremey Hansen to orbit the moon in 2024
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Well played.
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A little background
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Once in a while….
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So I just read a few comments from people concerned about “what if they miss the lunar slingshot” (they are on a free return trajectory and never reach earth’s escape velocity). I understand orbital dynamics is “interesting,” but if you don’t have a clue you’re best bet is to keep it to yourself.
But then I saw a BBC story about “85 seconds” to “leave earth’s orbit.” They haven’t left earth’s orbit and never will, they have injected into a highly elliptical transfer orbit (what they should have said is they’ve left LOW earth orbit). So I guess it’s understandable lay people are saying stupid things when the BBC is as well.
But then I saw a BBC story about “85 seconds” to “leave earth’s orbit.” They haven’t left earth’s orbit and never will, they have injected into a highly elliptical transfer orbit (what they should have said is they’ve left LOW earth orbit). So I guess it’s understandable lay people are saying stupid things when the BBC is as well.
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This is the best part, once they come back and download the media were going to get 4K pictures and video of what Apollo 8 saw. Unbelievably cool.
HavokFour
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Well d’uh, somebody has to be.
OldSolduer
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So we finally get to see all those Alien/Nazi bases hidden on the Dark Side of the Moon?
OldSolduer
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This sort of lazy dismissal of average people is exactly why anti-intellectualism is on the rise.
Do you call out people when they say mist when it's drizzle? When they say fog when it's mist? What about hail when it's ice pellets? Anyone with a rudimentary understanding of meteorology, a science far more practical than orbital dynamics, should know the difference between those phenomena...
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I apologize for my poor choice of words.
What I should have said is “it’s understandable that the average person is asking questions when the BBC can’t be bothered to explain it correctly.”
In my defence, I actually took the time to reply to comments to explain , as simply as I could, how their orbit works.
As for your second comment, the BBC is not “people.” There should be a reasonable expectation they get it right.
However, rereading my original comments the one you highlighted isn’t the most concerning one. It’s the one regarding if you don’t understand then keep your mouth shut which is more concerning.
By the way, I respectfully don’t agree with you on why anti-intellectualism is on the rise, nor do I agree there is ample evidence that is the case. I think what is actually going on social media has given everybody a voice, but certain groups of people use it the most. Intellectuals and professionals don’t have to use it (or if they do, it’s in private areas) as they have other means. The average person doesn’t feel the need to. It is the “common sense” (because I don’t understand and/or agree with the facts) and “the sky is falling, listen to the science” (they don’t understand) groups that are pitted against each other in a perpetual struggle usually uninformed by facts.
Yes, I know that is cynical. But in any case, I’m going to continue to try to inject facts, backed up by references when required, because it gives me some sense of making a positive contribution to society. I also try very hard to be empathetic and admit when I’m wrong and apologize.
Oldgateboatdriver
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Actually, Baz, the trajectory they are on will ultimately not be an elliptical one, but a combination of different ellipses. The original one, around the Earth in almost circular form was the first one. After TLI, they are now on a second elliptical one (third, actually, if you count the slingshot one) - if there was no moon, that trajectory would take them to an apogee from which they would then come back around the Earth on.
However, this current trajectory takes them in front (not behind) the Moon's position on it's orbital path. At some point, (known as Lagrangian point L1)the two gravity (Earth-Moon) will cancel one another out, after which they will be pulled by the moon's gravity more than Earth's. This will inflex their trajectory away from the current elliptical one and put them on an elliptical course towards the moon in front of which they will pass to then be slingshot back towards the Earth in yet another different elliptical course.
Because of all the various ellipses used, if you could look at their overall course from above, it would not look like an actual ellipse, but a weird series of curves making a strange figure eight (with a very small upper loop and a double loop in the bottom).
All of this is happening, of course, in orbit around the Earth for all (i.e. at no point does the Moon or Artemis escape Earth's gravity to the point of not returning).
Of course, in the mean time all of this, including Earth is still in orbit around the sun, and if you could single out the trajectories of Artemis by looking from above from the Sun's perspective, it would not even make a closed figure eight, because the Earth will have traveled in it's own orbit during the 10 days mission.
You really want to explain all that to people in 30 seconds news programs?
/Pedant off
However, this current trajectory takes them in front (not behind) the Moon's position on it's orbital path. At some point, (known as Lagrangian point L1)the two gravity (Earth-Moon) will cancel one another out, after which they will be pulled by the moon's gravity more than Earth's. This will inflex their trajectory away from the current elliptical one and put them on an elliptical course towards the moon in front of which they will pass to then be slingshot back towards the Earth in yet another different elliptical course.
Because of all the various ellipses used, if you could look at their overall course from above, it would not look like an actual ellipse, but a weird series of curves making a strange figure eight (with a very small upper loop and a double loop in the bottom).
All of this is happening, of course, in orbit around the Earth for all (i.e. at no point does the Moon or Artemis escape Earth's gravity to the point of not returning).
Of course, in the mean time all of this, including Earth is still in orbit around the sun, and if you could single out the trajectories of Artemis by looking from above from the Sun's perspective, it would not even make a closed figure eight, because the Earth will have traveled in it's own orbit during the 10 days mission.
You really want to explain all that to people in 30 seconds news programs?
/Pedant off
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