When Artemis II launches, it will be more than a crewed journey around the Moon.

It will also be a major test of how we move data between the Moon and Earth.

On board the Orion spacecraft is the Orion Artemis II Optical Communications System (O2O), a laser communications terminal that uses infrared light instead of traditional radio waves. This higher frequency light allows dramatically higher data rates up to 260 megabits per second for a fraction of power and weight, enabling 4K video, high resolution imagery, and science data to flow between Orion and Earth.

To make this possible, the ground-based laser must find a small spacecraft near the Moon with extraordinary precision. That’s where FreeFlyer comes in.

Pointing a Laser at a Moving Target Near the Moon

O2O is supported by an optical ground terminal located at NASA’s White Sands Gound Terminal (WSGT), where telescopes will track Orion as it moves through cislunar space.

For the Artemis II mission, a.i. solutions’ Ty Burney of the O2O team explained how FreeFlyer is deployed at White Sands as part of the concept of operations to generate pointing files for these telescopes.

  • Mission control sends an updated trajectory for Orion as the mission progresses.
  • This trajectory is ingested into a FreeFlyer mission plan as an ephemeris file.
  • FreeFlyer then computes the following for each ground terminal:
    • Azimuth and elevation angles for the downlink telescopes, indicating where Orion will appear in the sky based on the time the light left the spacecraft.
    • A point ahead angle for the uplink laser, which points slightly ahead of Orion so the light intersects with the spacecraft’s location when the beam arrives.
  • The mission plan also checks separation angles to enforce constraints, such as avoiding the Sun.

The output is intentionally simple: plain text pointing files with time tags, range and range rate, and azimuth/elevation for both receive and transmit beams. These files are handed directly to the optical teams to drive the telescopes.

For the operators, this is a straightforward workflow. Under the hood, it is a very demanding astrodynamics problem.

Microradian Accuracy and “Apparent” vs. “Geometric” Position

Optical communications are far less forgiving than traditional radio frequency (RF) links. For O2O, the team needs to hold the telescopes to tens of microradians of pointing accuracy relative to Orion’s apparent position in the sky.

FreeFlyer’s standard pointing functions provide geometric line-of-sight vectors, which are precisely what most flight dynamics systems need for orbit analysis, maneuver planning, and coverage studies. However, for laser communications, the team needed to go a step further. They modified the mission logic to account for light time, stellar aberration, and precise Earth orientation data, rather than relying solely on instantaneous geometry. They also introduced a point ahead correction, so the uplink beam intercepts Orion at its exact location when the photons arrive.

To build confidence, the team validated their FreeFlyer outputs against independent analysis tools based on SPICE data and matched the results to within roughly 1 microradian, well within the pointing requirement.

In other words, the same astrodynamics engine that propagates orbits and analyzes maneuvers is now helping keep a laser locked onto a crewed spacecraft near the Moon.

Designed for Operations, Not Just Analysis

What’s interesting about this use case is its operational capability.

The O2O team isn’t running elaborate visualizations in the control room. FreeFlyer’s 2D/3D displays are available when engineers need them. During mission operations, the priority is speed: ingest the latest trajectory, generate updated pointing files, and deliver them to the optical team with minimal delay.

The approach to using analysis grade astrodynamics wrapped in simple, repeatable workflows is consistent with how FreeFlyer is used across many other missions. This involves:

  • Reading trajectory and tracking data;
  • Running precise orbit propagation and geometry computations; and
  • Generating mission products that other systems and operators consume (in this case, pointing files that drive an optical terminal)

For Artemis II’s O2O system, this allows the ground segment to leverage flight-tested, commercially supported software instead of maintaining a unique internal tool specifically for this mission.

Looking Ahead: What Artemis II Teaches Us About Future Missions

NASA’s Exploration and Space Communications (ESC) projects division describes O2O as a pathfinder for operational laser communications beyond low Earth orbit. It can downlink 4K video and transmit high-rate science and mission data between the Orion spacecraft and the ground system. The lessons from Artemis II will have lasting impacts on future lunar and deep space missions, where high-volume data and tight pointing budgets become the norm rather than the exception.

For the FreeFlyer ecosystem, the O2O exemplifies how:

  • A general-purpose astrodynamics engine can be adapted to very specialized problems, such as optical terminal pointing.
  • Mission teams can incorporate this capability into lean, operator-focused workflows that produce the exact products their ground systems need.

Having a flexible yet validated astrodynamics backbone will become more important as more missions begin to utilize laser communications, high-precision optical navigation, and complex cislunar trajectories.

If your team is working on next-generation communications, navigation, or cislunar operations, and you’re interested in how FreeFlyer can support similar pointing and trajectory workflows, we would be glad to share more about the insights gained from projects like O2O on Artemis II.

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