Home Artemis-1 Trajectory

Trajectory visualization of the Artemis-1 Mission

Artemis-1 is the first in a series of missions in the Artemis program; a NASA program that the Canadian Space Agency, European Space Agency, and Japanese Space Agency are partners on. This program aims to land humans (including the first woman) on the Moon, and will eventually include a space station named Gateway in a Near Rectilinear Halo Orbit around the second Lagrange point near the Moon.

Artemis-1 is an uncrewed flight aimed to test the Space Launch System rocket and the Orion capsule it carries. Its trajectory includes a half-revolution of a Distant Retrograde Orbit (DRO), a type of orbit around the Moon that is computed in a multi-body model, such as the Circular Restricted Three-Body Model (CR3BP).

Artemis-1 launched on November 16, 2022, and actual and future states of the Orion capsule are provided by NASA on this page . The data file at the bottom of the page contains the position and velocity states (in km and km/s respectively) at evenly-spaced times (in UTC) in an Earth-centered J2000 inertial frame. These data, known as ephemerides, are animated in different frames, as shown below, and an explanation follows.

In the plot on the right, the trajectory of the Orion capsule (in magenta) is shown in an Earth-centered J2000 ecliptic inertial frame. This animation shows how the capsule moves through space and comes close to the Moon (in red) twice, performing burns during close passes of the Moon to insert into the DRO and then return back to Earth (in blue).

In the plot on the left, this same trajectory is moved into a pulsating-rotating frame. In this reference frame, the Moon and Earth are fixed on the x-axis, and the distances between the Earth and Moon are normalized to be a constant value (384400km, the average distance between the Earth and the Moon). Rotating frames are described in more detail in my post on resonant orbits . Since the Moon orbits the Earth along an elliptical orbit, the actual distance between the Earth and Moon varies. By using a pulsating reference frame, this distance is made constant and the gravitational influences on the trajectory by these bodies is more apparent. The half-revolution of the DRO is made clear in this reference frame, and is the smaller oval orbit that the spacecraft takes between the two close passes of the Moon.

Credits and technical details

The ephemerides used were downloaded on December 5, 2022 (updated versions of the ephemerides may have been posted since then). The Navigation and Ancillary Information Facility's SPICE toolkit and SPICE kernels were used to generate the Moon trajectory and for frame rotations. The Spiceypy module was used to interface with the SPICE toolkit in Python. Matplotlib in Python was used to generate the animation.