# What was the speed (avg, min, or max) of ARTEMIS-P1 spacecraft as it orbited L1 and L2

If not specifically ARTEMIS-P1, then what is the average speed (or mins and maxs) of a spacecraft orbiting EM L1 and L2 in halo and Lissajous orbits?

Are there varied orbital periods for those points? If so, what is the minimums and maximums?

I started, but did not complete, Classical Mechanics as an undergraduate, so I will not understand a highly technical answer.

• I had forgotten to consider it being as described orbiting the Earth. I am wondering if an astronaut was in a spacecraft as depicted in the video about the JWST youtube.com/watch?v=IyyQqaF4tNY would the vertical component (for lack of a more accurate term) of its orbit appear to be moving faster? – Bob516 Nov 1 '18 at 18:21
• What's really going to bake your noodle are the Lagrange point captures of P1 and P2 shown in the video found at svs.gsfc.nasa.gov/3787 – uhoh Nov 1 '18 at 23:19
• However, P1 and P2 were only in Earth-Moon Lissajous orbits for a period in late 2010/2011, after capture from Earth orbit. (Stage 3) Then at the beginning of Stage 4 they were transferred to high eccentricity lunar orbits. "In early June 2011 P1 was commanded to insert into lunar orbit by performing a series of periselene burn maneuvers; P2 followed suit shortly after. By July 2011 both P1 and P2 were in stable equatorial, high-eccentricity orbits, of ~100 km x 19,000 km altitude." – uhoh Nov 1 '18 at 23:34
• cont. "These are stable, 26 hr period orbits with inter-probe separations 500 km-5RE. One probe is in a retrograde and the other in a pro-grade orbit, such that the precession rates of their line of apsides will walk relative to each other by 15-20 degrees per month; in ~2 years the lines of apsides will cover a full circle, resulting in a wide range of inter-probe vectors relative to the Sun-Earth line and lunar wake crossings from a wide range of altitudes." i.stack.imgur.com/TREtk.gif – uhoh Nov 1 '18 at 23:34
• @ uhoh that is all tremendous information, thank you. All these questions I have been asking are for a novel I am writing. I am wanting an astronaut to be in either a halo or Lissajous orbit, and even though the astronaut would be well aware they are actually orbiting the Earth, I want the astronaut to be thinking about the imagine of orbiting around nothing, L1 or L2. – Bob516 Nov 2 '18 at 18:04