NASA has published a detailed account of the engineering behind Artemis III's planned rendezvous with commercial lunar lander test vehicles. The central challenge is not simply getting Orion close enough to attach. It is proving that spacecraft built by different organizations can recognize one another, exchange information, connect safely and behave as a single vehicle after docking. In the October 30 episode of Houston We Have a Podcast, NASA Human Landing System engineers Kent Criswell and Reid Ruggles explain two different approaches to that problem. Blue Origin's development vehicle would let Orion control the docked combination. SpaceX's Starship test article would control the joined stack itself. The conversation was recorded August 10, so its technical descriptions should not be mistaken for a same-day hardware readiness announcement. AI-generated image Conceptual docking hardware in a test facility, not flight-qualified hardware. Credit: Cislunar News, AI-generated. 443 NASA podcast episode October 30 Publication date, 2026 August 10 Interview recorded, 2026 Two test vehicles, two control arrangements The episode describes Artemis III as a low Earth orbit mission in which a crew aboard Orion would practice operations with commercial lander test articles. Commercial rockets would launch those vehicles, while the crew would launch aboard Orion on the Space Launch System. These are development spacecraft intended to reduce specific risks before later missions attempt crewed lunar landings. Criswell, NASA's HLS lead systems engineer for Blue Origin, identifies the company's test vehicle as Mark 2-D. Its crew module would closely resemble the module intended for the lunar lander, with structure supporting radiators, solar panels and thrusters. It would not carry the BE-7 main engine used for lunar landing. Reaction-control thrusters would provide the maneuvering and attitude control needed for this demonstration. Orion would approach the Blue vehicle as the chaser. Blue's docking system would provide the passive side of the interface, while Orion would provide the active side. Once connected, Orion would control the combined stack. Criswell also describes a test objective in which astronauts enter the Blue crew module and evaluate its environmental control and life-support system. Ruggles, NASA's HLS lead systems engineer for SpaceX, describes a different configuration. The SpaceX test article would be a close derivative of the V3 Starship upper stage, adapted with a docking interface at the nose and the communications and mission systems needed to work with Orion. After docking, Starship would control the combination. That difference makes the control handoff a practical test objective, not a minor detail on a spacecraft diagram. Planned test Blue Mark 2-D Starship test article Docking location Side Nose Docked stack control Orion Starship Design emphasis Crew-module and interface tests Modified V3 vehicle and interface tests Docking starts before metal touches metal A docking mechanism can be mechanically compatible and still sit inside a difficult operational problem. The approaching spacecraft must determine where the target is, how it is moving and whether the next maneuver remains safe. Communications, sensors, flight software and thrusters all participate before the docking rings meet. The interview repeatedly returns to the value of testing those systems together rather than treating each as an isolated component. Ruggles points to the appearance of the target as one example. Orion's lidar and visual systems must acquire the docking interface against the actual vehicle behind it. Shiny stainless steel can present a different scene from a surface covered in white spacecraft paint. A ground test can investigate pieces of that behavior, but an orbital approach brings the lighting, geometry and moving vehicles together in the environment where they must work. Thruster interaction is another concern. As Orion maneuvers nearby, its exhaust can strike the target spacecraft. Engineers want to see how the other vehicle responds, not merely whether Orion executed its own command correctly. That is particularly important near contact, when an unexpected movement can change the conditions the docking hardware has been designed to accommodate. Criswell describes rendezvous, proximity operations and docking as a sequence with different phases and communications needs. Holding the correct attitude is part of the job throughout that sequence. The eventual connection must occur with forces and motion that the interface can tolerate. Successful docking therefore provides evidence about a network of systems, including the human operators watching and responding, rather than only about a set of latches. Earth orbit brings its own thermal problem Operating near Earth is useful for an early crewed demonstration, but it does not reproduce the environment around the Moon. Ruggles highlights reflected sunlight from Earth as a substantial heat input. Orion was designed for deep-space operations, and the thermal loads imposed during this demonstration require mission planners to consider how long the spacecraft can remain in particular conditions and how its cooling system responds. The orbit also brings repeated transitions between sunlight and shadow. Temperature changes can alter the dimensions and behavior of mechanical components. Docking hooks and other mechanisms do not operate independently of their thermal environment. Flight testing gives engineers a way to compare predictions with actual behavior while the spacecraft experiences those cycles. Orientation connects the thermal problem to the docking architecture. Criswell says Orion prefers an orientation with its tail toward the Sun. A lander attached at its side creates a different geometric arrangement from a vehicle attached at its nose. Solar arrays, radiators and control systems must work within the resulting configuration. The control authority assigned to each docked pair is therefore tied to a larger set of power and thermal constraints. Those differences limit what can be claimed from a successful Earth-orbit test. It could demonstrate important interfaces and operations without reproducing every condition of a lunar mission. Cryogenic propellant storage, lunar insertion and surface operations pose other demands. The useful question is which uncertainties the demonstration retires, and which still require separate evidence before people depend on the landing system near the Moon. AI-generated image Conceptual illustration of sunlight and shadow in Earth orbit, not a mission trajectory. Credit: Cislunar News, AI-generated. The launch campaign is part of the experiment Artemis III would also test coordination among several launch and spacecraft organizations. Ruggles describes the challenge of integrating SLS and Orion with New Glenn and Blue's development vehicle, plus Super Heavy and Starship. A spacecraft can be ready on its own and still miss the conditions needed to participate in a joint mission. The campaign has to produce compatible opportunities, not just independent launch successes. Low Earth orbit provides more launch opportunities than the later lunar missions, according to the interview. The team is considering repeating ground tracks to create multiple chances to launch, although individual windows may still be instantaneous depending on vehicle capability. That gives the demonstration useful flexibility without eliminating the need for precise timing and coordinated operations. Criswell contrasts that flexibility with the constraints of lunar missions. Communications geometry and sunlight at the south pole can narrow the available opportunities. Early missions need suitable illumination for power generation, and those needs intersect with the trajectory and launch sequence. Practicing a multi-vehicle campaign near Earth is a way to build experience before those restrictions become