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RCAF Col Jeremey Hansen to orbit the moon in 2024

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.
 
Baz said:
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.
Click to expand...
Homer Simpson Nerd GIF
 
Baz said:
So I guess it’s understandable lay people are saying stupid things when the BBC is as well.
Click to expand...
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...
 
Furniture said:
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...
Click to expand...
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.
 
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
 
Oldgateboatdriver said:
You really want to explain all that to people in 30 seconds news programs?
Click to expand...
No, I want the 30 seconds news program to use the right terminology to describe their current trajectory, after the TLI:
  • not "they've left earth orbit" which is incorrect, they never do
  • to "they've left LOW earth orbit" which is correct

And, actually OldGateBoatDriver (by the way, I'm not arguing, I'm being pedantic):

Their current (post TLI) trajectory is an elliptical orbit around the earth, perturbed by every other body in the universe (the largest being, obviously, the moon). All the other ellipses you described (except the tranistion to the moon being the primary gravity well) are the results of burns. At the point the moon becomes the primary gravity well the orbit will become an ellipse around the moon, perturbed by all other bodies. At this point they will be part of the moon / Artemis system, itself orbitting the earth (on an elliptical path, perturbed by all other celestial bodies).

As well, they won't past through L1, they'll pass by it. They will be well ahead of the straight line between the earth and moon wrt the moon's orbit.

But the point is, at no point do they reach earth escape velocity; their TLI is deliberately kept just below that so that in any case they will return to the earth (unless their orbit intersects that of the moon) and don't need to have a moon "slingshot" (although I think, in the case fo Artemis 2, they are using it to get back quicker). It's kept "just" below so that it is the fastest transfer orbit without being above escape.

Maybe, however, organizations like the BBC should reinforce that, in space, everything is always orbitting everything else, and never "just drifting." That is basic science, and might be a simple way for lay people to understand the physics. Because I find it incredibly dismissive when people say "it's physics and math" as if those things are some magical panecea, and I could see contributing to a "rise in anti-intellectualism."

And know I'm thinking out loud. Even if you somehow come to a full stop wrt the object your orbitting, in which case you will immediately fall towards it, you are still orbitting it. It's just that your tangential velocity is now zero, and the ellipse has flattened to a line, with the invariable result that you will crash into it. But the physics and math is elegant, not mystical.

Another thought bubble: my oldest son did the IB program, and they did a really good ob of linking subjects. So, for a simplified example, at the same time they discussed orbits in physics, they did calculus in math , and studied the Principaia (sp?) in english. To me, everyone should have the opportunity to do that, to understand how elegant the world we live in is (outside of human failings).

/pendant


Should I take the lesson from these comments that I'm not only a nerd, and at times pedantic, but I'm also an asshole? I do often wonder if my means of engaging is just as much of a problem as the other's I've described. They've also been known to take a lot out of me.

Maybe the times I've decided to disengage are indicative of what I should do permanently. I am feeling really mad at the world lately, and yes, it has surfaced in my interactions.
 
Baz said:
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.
Click to expand...

And the underlaying point that it’s a risk management methodology to ensure worse case scenario is that they don’t escape Earth’s orbit if the slingshot isn’t 100% accurate, should be seen formations that NASA is doing its best to think things out deeply this time around, and learning from Apollo 1, Challenger and Columbia.

brihard said:
Homer Simpson Nerd GIF
Click to expand...
Baz said:
Well d’uh, somebody has to be.
Click to expand...

1775311391004.gif

Baz said:
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.”
Click to expand...

And they have appropriate staff to get it right.

Oldgateboatdriver said:
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.
Click to expand...

Multi-Molnyia, or, true to origin… “множественные молнии”
 
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