A portion of the far side of the Moon looms large just beyond the Orion spacecraft in this image taken on the sixth day of the Artemis I mission by a camera on the tip of one of Orion’s solar arrays. (Image: NASA)

NASA recently launched Artemis I, a test mission to prepare the U.S. to send humans to the Moon for the first time since 1972 — and “set up long-term operations” on the Lunar surface. The mission saw an uncrewed Orion spacecraft launch atop the $4.1-billion Space Launch System (SLS) vehicle into lunar orbit.

Launched at 1:47 a.m. on November 16, Artemis I will travel for 25 days, 11 hours, and 36 minutes — approximately 1.4 million miles — before a December 11 splashdown off the coast of San Diego.

The launch took place at Launch Pad 39B at the Kennedy Space Center in Florida with support from University of Central Florida alums, faculty, and students. However, it didn’t go off without a hitch.

While waiting ahead of launch, sensors detected yet another fueling leak, which served as a constant problem during previous launch attempts. Then another leak arose during this countdown, it seemed to many that we would witness yet another scrubbed launch — or worse, a rollback to the Vehicle Assembly Building (VAB) for repairs.

Here is an edited-for-clarity Tech Briefs interview on the trials and tribulations of the Artemis I launch with Dr. Phil Metzger, UCF faculty member and a Planetary Physicist , who recently retired from NASA’s Kennedy Space Center, where he co-founded the KSC Swamp Works. More of his work can be found here .

Tech Briefs: What kind of issues did the delays bring?

Metzger: Whenever repair work is done on a NASA rocket like the SLS, things need to be taken apart and put back together to get access to the repair area. This often includes disconnecting electrical connectors, which sometimes carry more than 100 “pins” with different signals in them. Every single pin in these connectors will be reverified to ensure that the pin did not get bent over when reconnecting the connector. Every pin is tracked in a computer system, and the engineers will look through their testing logbooks to find out if they did any tests that have proven these pins are working after the connector was re-mated. If the logbook does not show that a pin has not been retested, then they will schedule an extra test to get it done before proceeding with countdown.

On the sixth day of the Artemis I mission, Orion’s optical navigation camera captured black-and-white images of craters on the Moon below. (Image: NASA)

This can be laborious, depending on how many connectors needed to be disconnected to do the repair. Also, when fluid lines are disconnected, then they need to do leak tests to ensure they will not leak on launch day. When an area in a rocket is “buttoned up” for flight after the repairs are complete, they will do inspections and closeout, which requires documenting that all the screws were re-installed with the correct procedures and torques. This is all standard practice for the engineers and technicians working on rockets, but the point is that every time a launch gets scrubbed and a repair made, quite a bit of work has to be done before the next launch attempt.

The earlier scrub of the SLS required the entire vehicle be rolled back to the VAB. That requires a lot of work to prepare the mobile launch platform (MLP) for travel, bring the crawler up the pad under the MLP, and most of a day bringing it back to the VAB and setting up there for access to the rocket. Then, the opposite process has to be done to take the vehicle back to the launch pad again. After arriving at the launch pad, ground systems need to be reconnected to the rocket and the entire process of preparing the launch pad for count down needs to be repeated, which is a multi-day process.

Tech Briefs: How did you know it was safe despite the missing insulated caulking? What kind of problems could that trigger?

Metzger: NASA has the world’s most advanced computer modeling capabilities to simulate the effects of changes like this. They can analyze how the missing insulation will affect the thermal environment inside the rocket, and they can simulate the aerodynamic forces over the area during flight to see if the missing caulk will have an effect on the other materials around it when the air is flowing across at high speed. Typically, when a problem is found like this, the discoverer will initiate a problem report. The director of the mission will ensure the report is assigned to the correct systems engineering group — in this case, the thermal control system engineers.

Those engineers will begin analysis to see if it is a very clear non-problem, and in either of these cases they will write up the explanation and process the report for approvals. The problem report is reviewed by quality control engineers, project engineers, and project managers to make sure everyone is in agreement with their analysis. In the case of a high-profile problem, they will be required to present the issue at a program board with the top-level managers of the program where they will be grilled to ensure they did a thorough analysis. If the board has any doubts, they will require the engineers to go back and do more analysis or even experimental work to buttress their case before proceeding with launch.

Tech Briefs: What are the potential risks/hazards the SLS could encounter launch/post-launch?

Metzger: There are millions of things that could go wrong, and the only reason rockets are able to fly so successfully is that we have spent many decades launching rockets, building up a deep experience and a highly skilled workforce that passes on their skills to the next generation of engineers. (Skills retention is one reason why it is crucial for the space program to always keep moving forward.)

Some of the problems could be: electrical systems having anomalies induced by the extremes of hot and cold in space or induced by radiation; mechanical systems (like pins that release hardware from each other, or antenna gimbals) not moving because the materials did not respond to the vacuum/thermal environment of space exactly as we expected; software anomalies that were undetected because they only occur in specific circumstances in a highly integrated space operation; common failures of electronic components, which is expected so space systems always have redundancy.

In the first flight of a new vehicle, they will likely find hundreds of small anomalies and the team will be busy studying them to ensure they do not pose a serious risk and to learn how to correct it before the next flight. Even by the end of the Shuttle program, we were still finding dozens of small anomalies in every flight. The vehicles are so complex that it is nearly impossible to have a perfect flight without any anomalies.

Tech Briefs: What kind of groundwork are you trying to lay for future missions with this mission? What’s the desired data acquired?

Metzger: This mission is testing out key architectural pieces of the Artemis program, including the launch vehicle, the Orion space capsule, and the European Service Module. It is demonstrating the orbital dynamics and operational integration to fly this vehicle into deep space and into a high lunar orbit. This also verifies communications systems that bring the data back to Earth, the tracking and navigation, and really every system in these elements of flight hardware. This is important before putting astronauts in the spacecraft so we can be sure we can keep them safe and bring them back home after the mission.

The scientific payloads that were hitchhiking on the SLS are also contributing to our future missions. The Biosentinel payload is studying the effects of deep space on biological organisms, which is crucial to long journeys of astronauts beyond low-Earth orbit. The NEA Scout payload will do an up-close study of an asteroid, which will help pave the way to humans visiting asteroids in the future. Lunar Flashlight will study the ice at the poles of the Moon, which is a crucial step to learning about that resource, which can be game-changing for future operations in space including missions to Mars, since the lunar ice can be converted into rocket propellant.

Tech Briefs: Any other thoughts on Artemis I and the mission?

Metzger: This mission is crucial as the U.S. returns humans to the surface of the Moon, since this time we intend to do more than simply leave flags and footprints — we intend to stay. We will set up long-term operations on the Moon, revolutionize the infrastructure of space exploration in the cislunar region of space, and move onward to exploring Mars. This mission moves us toward an exciting future.

Artemis II will see a human crew placed into orbit around the Moon no earlier than 2023, while Artemis III — set for 2024 or 2025 — will see astronauts leave footprints on the lunar surface once again.