Proper halo orbits have the same period for their in-plane oscillations and out of plane oscillations, so they are closed orbits with roughy circular motion in the rotating frame, whereas Lissajous orbits are those where the two periods are unequal. They could be closed with a period ratio that is a rational number or be open, non-repeating orbits. Either way they will have "etch-a-sketch" or "squiggly" Lissajous-like motion.
- What is the difference between halo orbits and Lissajous orbits?
- Why is DSCOVR in a Lissajous orbit? Wouldn't a halo orbit completely avoid the Sun exclusion zone?
Question: Was Queqiao in a halo or Lissajous orbit? Why do sources disagree? Considering that Queqiao's radio signals were regularly monitored by amateur radio astronomers and its doppler shift well documented, it should be relatively easy for those skilled in the art to determine its trajectory with great precision. From an orbital-mechanical perspective don't understand why this couldn't be nailed down.
Related and may provide helpful information to finding an answer:
- How can one know that Chang'e-4 was in “locked to the Queqiao” from this SDR spectrogram?
- What is the purpose of the satellite that China is putting in lunar orbit?
- What radio frequency does China use to communicate with the Chang'e-4 satellite?
- Are large halo orbits around L₁'s and L₂'s preferred over small orbits for reasons other than geometry?
- Transmission time per day for Chang'e 4?
- Why is Queqiao's dish antenna so big? (Chang'e-4 relay satellite) Largest ever on/near the Moon?