JWST orbit around L2

DenisSchef

Hello,
I can understand the principle of orbits around a planet or stars since they have a gravity center.
How it is possible to orbit around L2, that is a virtual point with no mass, is therefore JST condemned to use more fuel to maintain such an orbit limiting its life cycle much more than a device like Huble?

Last edited:

billslugg

Here is a grossly simplified explanation. At L2, the spacecraft orbits the Earth once per year. The Earth orbits the Sun once per year. The spacecraft thus never moves from its spot. Anything near that spot tends to gravitate towards it. With just the right position and velocity JWST can orbit that spot.

Pogo

At this distance from the sun (1 AU + 1.5M km), the spacecraft would orbit the sun longer than a year, most of the time far from Earth. At L2, the gravity of the Sun and Earth are approximately equal, the Earth sorta drags the craft along with it, keeping it close. But, it’s not perfectly stable, hence, the fuel for stationkeeping.

DenisSchef

Here is a grossly simplified explanation. At L2, the spacecraft orbits the Earth once per year. The Earth orbits the Sun once per year. The spacecraft thus never moves from its spot. Anything near that spot tends to gravitate towards it. With just the right position and velocity JWST can orbit that spot.

Thanks... Difficult to imagine that when i see the JWST course on sketch, any link to an animation?
Our brain is basically not formatted to imagine such things

DenisSchef

At this distance from the sun (1 AU + 1.5M km), the spacecraft would orbit the sun longer than a year, most of the time far from Earth. At L2, the gravity of the Sun and Earth are approximately equal, the Earth sorta drags the craft along with it, keeping it close. But, it’s not perfectly stable, hence, the fuel for stationkeeping.

DenisSchef

Thanks... Difficult to imagine that when i see the JWST course on sketch, any link to an animation?
Our brain is basically not formatted to imagine such things

I found something very interesting :
View: https://youtu.be/7PHvDj4TDfM
all is trying to forget that we are not in a flat planar dimension.. pfff not easy !

Atlan0001

Atlan0001

Here is another illustration:

What is a Lagrange Point? | NASA Solar System Exploration

Illustrations posted less than a minute apart. Not bad at all.

Now if only we can have space island stations, cities, and other customized functional facilitations orbiting L4 and L5 . . . beginning, and in ever growing numbers.
---------------------------

It's a multi-dimensional Multiverse Universe.

Last edited:

DenisSchef

Thanks,
I'm not sure it's a good idea to colonise our solar system, study of course. Humanity is the cancer of our earth... we destroy whatever we find... we have almost destroyed the earth and our near orbit with our space trash... let's hope we'll be wise enough to not go further...

Happy new year from beautiful Switzerland, we are almost in 2022 here

Moderator
Thanks,
I'm not sure it's a good idea to colonise our solar system, study of course. Humanity is the cancer of our earth... we destroy whatever we find... we have almost destroyed the earth and our near orbit with our space trash... let's hope we'll be wise enough to not go further...

Happy new year from beautiful Switzerland, we are almost in 2022 here
Personally, I'm all for the expansion of the Human Race to other parts of the solar system and beyond. One's hope is that by the time we figure out how to do so safely, we'll have become more respectful of our environment (both here on Earth and abroad).

A very happy new year to you as well!

-Wolf sends

Helio and COLGeek

Atlan0001

No species is respectful of its environment. Or, rather, all that were so respectful are now extinct . . . aborted. Respect is not how nature plays the game of life, survival, remaking environments to suit, on and on, evolution and prosperity up through the pyramid to the top.

One of the reasons the unborn must be born is because it's reached the point of befouling, trashing, the womb only too greatly. It has all the newly found and growing energies, organs and limbs, that is to say all the structure and infrastructure, wants and needs and 'has-to', to begin birthing out from the womb or expanding from the nest (the Old World).

If there are no excess energies, no excesses, it is not the carrier species nature needs to expand life from the mud hole, for life's prosperity and survival. Prosperity, including that of life itself, is defined by excess. We are not still-born Utopian perfect beings; we do not know exactly what is waste and what is not. Or if we do know, we do not know if it is required by the nature of things to move us to begin birthing, moving, out. Once more, we don't know that if we just stop the crapping, so to speak, stopping the awesome energies at the same time creating it, we haven't committed our particular civilization's suicide, if not species suicide.

Last edited:

Helio

Thanks... Difficult to imagine that when i see the JWST course on sketch, any link to an animation?
You might find a better animation for L1. SOHO (solar obs.) is stationed there and it travels in a large halo orbit. This is because its data needs to be transmitted to Earth when the Sun isn't directly behind it, causing excessvie noise.

If you take the centrifugal force acting on an L2 object, based on a one year orbit around the Earth, as billslug mentioned, and equate it to the gravitational pull from both the Earth and the Sun, I think you will get the L2 distance.

This explains why there is a gravity well, where objects that the Moon pulls up the well slightly, will later pull it up the other side as it passes, then the Earth will drag it back toward the center.

Replies
3
Views
1K
Replies
1
Views
605
Replies
3
Views
2K
Replies
5
Views
1K
Replies
14
Views
2K