In Simple Terms
NASA plans to test two spacecraft built to carry astronauts to the Moon, but this mission will not land anyone there. Instead, the crew’s Orion spacecraft will meet and connect with each vehicle in space. What NASA learns could help it choose which one to use for a later Moon mission, even as both companies keep working toward lunar landings of their own.
A Test Before NASA Chooses
NASA is treating Artemis 3 as a crucial test before assigning either of the two spacecraft a landing role on Artemis 4. NASA Administrator Jared Isaacman has said the mission’s results will help the agency choose between the two candidates for later crewed trips to the lunar surface. But NASA does not plan to make its choice early. Isaacman said the agency will wait as long as it can, so it can base its decision on test data rather than relying only on plans and predictions.
Artemis 4 is intended to return people to the Moon’s surface in 2028, but which vehicle carries them will depend on what the two landers demonstrate during Artemis 3. The competition does not mean that one company will stop preparing if its vehicle is not chosen for that mission. Jeremy Parsons, Artemis program manager, said both companies are planning lunar landing operations in 2028. Development work can therefore continue on both vehicles, even though NASA will select only one to serve as the lander for Artemis 4.
The mission’s redesign is key to understanding what this test will involve. Artemis 3 was originally planned as a crewed trip to the lunar surface. Earlier this year, NASA reshaped it into a complex orbital test lasting about two weeks. The crew will not travel to the Moon’s surface, and astronauts will not board Starship during the docking test. Instead, NASA will gather information about how the spacecraft meet and how their systems work together, ahead of a crewed landing attempt on a later mission.
Three Spacecraft, One Carefully Choreographed Mission
The plan begins with Blue Origin launching its Blue Moon vehicle aboard the company’s New Glenn rocket. Once in orbit, Blue Moon will undergo checks to make sure it is ready for the test. Orion is scheduled to launch afterward atop the Space Launch System rocket, commonly known as SLS. The program aims to coordinate the launches so that Orion is ready to lift off as soon as possible after Blue Moon’s first launch.
That sequence requires multiple rockets and spacecraft to operate within a single timeline, with launches carefully coordinated in orbit. NASA modified SLS to suit the mission after changing Artemis 3 from a lunar trip into a test in low Earth orbit. The rocket’s upper stage was removed because the mission does not require Orion to travel beyond the orbit it needs to reach. Parsons explained that the rocket’s core stage can send Orion into that orbit without the upper stage.
Three days after Blue Moon launches, Orion will attempt to dock with it. The crew will then spend two days testing the guidance, navigation and communications systems involved in operating the two spacecraft together. These exercises are more than a practice run at bringing two objects close to each other in space. They will let NASA examine how systems needed for a future mission work together, and check that communications, position tracking and movement control function while Orion is near the lander.
On the sixth day of the mission, Starship is scheduled to launch. Before attempting to meet it, Orion will separate from Blue Moon and change its orbit, then move to dock with SpaceX’s vehicle. The Starship test window will be relatively short—about two hours. Artemis 3 astronauts will not enter Starship; the test will be limited to the docking operation and related checks. Orion and its crew will then continue with the rest of the mission.
The sequence reflects NASA’s aim of testing both spacecraft on a single flight while giving Orion a chance to interact with each one separately. The mission is not simply about proving that a vehicle can reach orbit. It is also about testing connections, communications and control of the spacecraft’s path. After the Starship test, Orion and its crew will have additional days to carry out other objectives before returning to Earth, depending on what the flight plan allows.
A Flexible Schedule—and Health Data on the Crew
Artemis 3 is designed to last 14 days, but the mission could be extended to 17 days if necessary. That flexibility gives NASA room to meet the test requirements while keeping the return to Earth central to mission planning. Days not devoted to docking can be used to pursue additional goals, but the activities follow a set schedule; the mission is not simply a series of maneuvers that can be performed in any order.
Alongside its assessment of the spacecraft, the mission will gather important data on the astronauts’ health. Artemis 3 will therefore test several aspects of readiness for lunar missions: how spacecraft perform in space, how well approach and docking procedures work, and how the crew fares during a relatively long flight. Parsons said the mission’s schedule was designed to help reduce risks, provide scientific information and assess the program’s capabilities before NASA moves on to a lunar landing attempt.
These goals help explain why Artemis 3 remains important even though it no longer includes a landing. The new plan shifts the focus from carrying out a surface mission to checking steps that a later lunar mission may depend on. If the tests uncover problems with docking or spacecraft systems, NASA will have a chance to address them before a crew is committed to a Moon landing. Collecting health data from the astronauts adds another dimension to the test, beyond the spacecraft themselves.
Development Challenges for Blue Origin and SpaceX
The mission schedule still depends on how the spacecraft and rockets progress. New Glenn has not flown since one of its vehicles exploded in May. Blue Origin says it expects launches to resume in November, but NASA currently has no backup plan for sending Blue Moon into space aboard another rocket. That makes New Glenn’s return to flight a critical part of the Artemis 3 sequence, since the current plan relies on it to launch the company’s lander.
Parsons, meanwhile, said work on the version of Blue Origin’s lander intended for the Artemis 3 test is going well. NASA has taken part in design reviews, and components of the vehicle are being brought together from sites across the United States. This points to progress in design and assembly, but it does not remove the need to resolve the question of when New Glenn will fly again, nor does it guarantee that the orbital test will go ahead as planned.
SpaceX is targeting another Starship test next month, with updates to its Raptor engines. The vehicle has encountered setbacks during earlier trials, including several explosions during test flights. Even so, it reached an important milestone in its most recent demonstration by entering orbit for the first time. That achievement marks progress toward making Starship ready to take part in Artemis 3, but it does not by itself establish whether the vehicle is prepared to carry out the docking the mission requires.
The two companies face different technical and operational challenges, but NASA will need each company’s spacecraft and rocket to perform the tasks in the required sequence. For Blue Moon, the test depends on a New Glenn launch, checks of the vehicle and a rendezvous with Orion. For Starship, the plan calls for a launch on the sixth day, after Orion has tested its first docking with Blue Moon; Orion must then move into an orbit that allows it to attempt the second docking. Announced plans alone are not enough—the test itself will show whether these systems can work together in a real mission.
What Will Artemis 3’s Results Decide?
The outcome will be more than a comparison of the two spacecraft’s designs. Orion will act as the vehicle that interacts with each lander, giving NASA teams a chance to assess a sequence of operations that must succeed before a crewed lunar landing. The agency will examine the data collected, including how navigation, communications and guidance systems perform, and use it to inform decisions about future missions. Isaacman has emphasized that Artemis planning will remain open to changes based on the data and circumstances, rather than being treated as a fixed plan.
Meanwhile, work is under way to assemble and test the crew and service modules for the Orion spacecraft intended for Artemis 4. That shows that preparation for the next mission is proceeding alongside preparations for the Artemis 3 test. It does not mean NASA will skip over what it learns from the test flight: the agency says it will continue to follow the data and adapt to what the results show. Progress toward 2028 is therefore advancing on two tracks at once—preparing Orion for the next mission and gathering practical evidence to help select a lander.
The timing makes the importance of that approach clear. Artemis 3 does not yet have a specific launch date, but Isaacman said liftoff is expected in summer 2027. Before then, the preliminary steps must move forward: New Glenn must return to flight as Blue Origin expects, SpaceX must continue testing Starship, and the launches of the spacecraft and rockets must be coordinated in the mission sequence. As the expected launch date approaches, actual readiness and the evidence produced by testing will remain key factors in determining what happens next.
The Bottom Line
Artemis 3 has become a two-lander orbital test that could shape NASA’s choice of vehicle for the return of astronauts to the Moon on Artemis 4 in 2028. Orion will attempt to dock first with Blue Moon and then with Starship during a mission designed to last 14 days, with the option of extending it to 17. NASA will also collect data on spacecraft systems and crew health. Both companies still face launch and testing challenges, and NASA says it will delay its choice as long as possible and base it on the results. The mission will turn plans into practical evidence that can help prepare for a future lunar landing.