<p>I'd like to plot the path of an object near L2 (like the Webb space telescope) in a rotating libration point coordinate system. That makes it is easy to distinguish halo orbits from more general Lissajous forms, etc. I expect to get Earth-centered coordinates from Horizons (see e.g. <a href="https://github.com/nealmcb/jwst_orbit" rel="nofollow noreferrer">nealmcb/jwst_orbit: Explore the orbit of the James Webb Space Telescope in Python</a>).</p>
<p>Here are details on the RLP coordinate system I'm looking for:: <a href="https://help.agi.com/stk/11.0.1/Content/gator/eq-rlp.htm" rel="nofollow noreferrer">Technical Notes - Rotating Libration Points</a></p>
<p>Putting the origin at L2 as they suggesst seems good.</p>
<p>I was hoping to find an implementation in astropy, but it doesn't seem to be there.
Has anyone implemented it for astropy or another open-source framework?</p>

CC BY-SA 4.0
2022-01-28T11:21:44.953Z
That's essentially what I did in the corotating frame plots here: https://space.stackexchange.com/a/57832/38535
PM 2Ring
CC BY-SA 4.0
2022-01-29T23:38:49.003Z
I did something like this [here](https://space.stackexchange.com/a/58050/12102) but in a less-than-rigorous way, I rotated with the Earth/Moon barycenter's instantaneous position rather than at a steady rate.
uhoh
<orbit><coordinate><lagrange-point><astropy>
Convert Earth-centered coordinates to rotating libration point (RLP) coordinates?
nealmcb
# Convert Earth-centered coordinates to rotating libration point (RLP) coordinates?

(Asked by: username_0 on 2022-01-28)

I'd like to plot the path of an object near L2 (like the Webb space telescope) in a rotating libration point coordinate system. That makes it is easy to distinguish halo orbits from more general Lissajous forms, etc. I expect to get Earth-centered coordinates from Horizons (see e.g. [nealmcb/jwst\_orbit: Explore the orbit of the James Webb Space Telescope in Python](https://github.com/nealmcb/jwst_orbit)).

Here are details on the RLP coordinate system I'm looking for:: [Technical Notes - Rotating Libration Points](https://help.agi.com/stk/11.0.1/Content/gator/eq-rlp.htm)

Putting the origin at L2 as they suggesst seems good.

I was hoping to find an implementation in astropy, but it doesn't seem to be there.
Has anyone implemented it for astropy or another open-source framework?

**Tags:** orbit, coordinate, lagrange-point, astropy
> **Comments:**
> **username_1**: That's essentially what I did in the corotating frame plots here: https://space.stackexchange.com/a/57832/38535  
> **username_2**: I did something like this [here](https://space.stackexchange.com/a/58050/12102) but in a less-than-rigorous way, I rotated with the Earth/Moon barycenter's instantaneous position rather than at a steady rate.  

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## 0 answers

