Introduction

When NASA's Artemis III mission finally launches, it won't be heading to the Moon as originally planned. Instead, the agency is reworking the mission into a critical orbital test—a proving ground for two privately built lunar landers from SpaceX and Blue Origin. Administrator Jared Isaacman recently told lawmakers that both contractors expect their spacecraft ready for an Earth-orbit rendezvous in late 2027, later than earlier schedules. This guide walks you through how NASA is assembling this test mission, step by step, from assessing contractor timelines to deciding on rocket configurations.

What You Need

• Space Launch System (SLS) rocket – specifically one of the existing upper stages or a future Centaur V stage
• Orion capsule – the crew vehicle for astronaut transport
• Two lunar landers – SpaceX’s Starship and Blue Origin’s Blue Moon (under development)
• Low-Earth orbit (LEO) or higher orbit – the altitude determines test conditions
• Astronaut crew – trained for orbital rendezvous and docking
• New Centaur V upper stage – purchased from United Launch Alliance for future missions
• Ground control and tracking stations – for monitoring the test

Step-by-Step Guide

Step 1: Confirm Contractor Readiness

Begin by verifying with SpaceX and Blue Origin that their landers will be ready for Earth-orbit testing by late 2027. Both companies have stated they can meet this timeline, though it's later than NASA's previous schedule. Hold regular readiness reviews to track progress and identify any technical or supply-chain delays that could push the date further.

Step 2: Define Mission Objectives

NASA must clearly state what Artemis III will accomplish in Earth orbit. The primary goal is to rendezvous and potentially dock the Orion capsule with one or both lunar landers. This tests docking mechanisms, communication systems, and crew procedures without the added complexity of lunar gravity or deep-space radiation. Decide whether both landers will be visited in a single flight or separate missions.

Step 3: Choose the Orbital Altitude

The altitude of the test orbit is a key decision. A low-Earth orbit (a few hundred miles up) saves the use of an existing SLS upper stage, preserving it for a later lunar landing attempt. A higher orbit, closer to the Moon's environment, allows more realistic testing but requires the upper stage. NASA must weigh the trade-off between saving hardware and getting better simulation data.

Step 4: Allocate the SLS Upper Stage

NASA has several SLS upper stages already built and in storage. If Artemis III uses a low orbit, it can skip using one of these stored stages, keeping it for the next mission (Artemis IV) that aims for a lunar landing. Conversely, if a higher orbit is chosen, one stored stage must be consumed. Monitor the inventory and plan accordingly. Note that future SLS rockets will use a new commercial upper stage, the Centaur V from United Launch Alliance, for missions after the stored stages are depleted.

Step 5: Refine the Flight Plan

The detailed Artemis III flight plan is still under review. Key questions include the precise orbit altitude, the sequence of rendezvous maneuvers, and whether the Orion capsule will dock with both landers or just one. Work with the astronauts and mission planners to simulate the procedures and validate timeline feasibility. Ensure that crew training accounts for any differences between low-g Earth orbit and the eventual lunar environment.

Step 6: Integrate the New Upper Stage

NASA is buying the Centaur V to pair with the SLS rocket after the existing upper stages are used up. For Artemis III, if the mission uses a stored stage, the Centaur V will not be needed yet. But prepare for its integration on future missions by running compatibility tests with the SLS core stage and the Orion capsule. This step ensures a smooth transition when the stored stages are exhausted.

Step 7: Coordinate with Contractors on Docking Interfaces

Ensure that the SpaceX and Blue Origin landers share compatible docking ports with the Orion capsule. Standardize communication protocols and power-transfer systems. Run joint simulations to uncover interface issues before launch day. Both landers may have different designs, so test each one separately.

Step 8: Establish a Firm Timeline

With a target of no earlier than late 2027, set interim milestones for each step: lander completion, Orion certification, SLS assembly, and crew training. Build in margin for delays. Communicate the schedule transparently to all stakeholders, including lawmakers who fund the program. The late-2027 date is the earliest possible; plan for it but be ready to adjust.

Step 9: Prepare for Contingencies

Develop backup plans for common mission risks: a lander delay, an SLS upper stage malfunction, or an orbit insertion issue. Because this is a test mission, some failures are acceptable as long as the crew is safe. Design abort scenarios that bring the Orion capsule back to Earth from any point in the mission.

Tips for a Successful Test Mission

• Save the upper stage if possible: Using a low orbit conserves the stored SLS upper stage for a future lunar landing, extending the life of the existing hardware.
• Test in the most representative environment: If a higher orbit can be achieved without breaking the budget, it provides better data for the actual lunar landing missions.
• Prioritize crew safety: Since this is an orbital test, ensure that all emergency systems are robust for an abort in Earth orbit, which is simpler than lunar abort but still critical.
• Keep communication lines open: Frequent coordination between NASA, SpaceX, and Blue Origin will prevent interface mismatches and schedule surprises.
• Document lessons learned: Every test—success or failure—yields insights for the subsequent Artemis missions. Establish a formal knowledge management system.
• Plan for the Centaur V transition: Even if not used on Artemis III, prepare the ground support and launch procedures to avoid disruptions when the new upper stage debuts.