NASA’s Artemis program is the main program (at least for now) of near-future deep space human exploration, aiming not just to return astronauts to the Moon but also to establish a sustainable presence, as a stepping stone for Mars missions.
The successful completion of Artemis I in December 2022 marked the first milestone, offering crucial insights and data essential for future missions. Now, with Artemis II on the horizon, NASA faces a monumental task – ensuring the readiness of both its technology and its teams for this mission.
Scheduled for launch in September 2025, Artemis II represents a culmination of over a decade of preparation and a staggering $55 billion investment in the Space Launch System (SLS), Orion capsule, and associated ground systems.
However, before humans can once again orbit the Moon, NASA must learn the lessons from Artemis I, address identified risks, implement necessary modifications, and test every component of the integrated SLS and Orion systems once again.
In an audit released on May 1, 2024, the NASA Office of Inspector General (OIG) delved into the Agency’s readiness for the challenges that lie ahead in the Artemis II mission, highlighting what went wrong during the first mission.
And no, we didn’t really know everything…
Since this will be a rather long article, here’s a summary to help you:
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Artemis II will be an important mission
Artemis II not only serves as a crucial step towards the eventual lunar landing of Artemis III with SpaceX’s Starship, but also as a complete testbed for vital systems onboard the Orion spacecraft.
Unlike Artemis I, which focused primarily on uncrewed system demonstrations, Artemis II places human lives at the forefront, necessitating thorough evaluations of critical survival and life support systems. This includes an array of components such as crew interface displays and controls, emergency and recovery communications equipment, stowage systems with crew support equipment, and the Environmental Control and Life Support System (ECLSS).
Additionally, Artemis II introduces specialized equipment designed to enhance crew safety during ground, launch, and ascent operations. Notable among these are the launch pad crew escape system and an active Launch Abort System, both critical safeguards in the event of emergencies or anomalies.
Then, with astronauts onboard, NASA’s human rating requirements come into play, ensuring that every aspect of the mission meets stringent safety standards. Human rating certification processes demand attention to detail, from design and development to certification and operation, with a focus on minimizing risks to crew members’ lives and well-being. We saw this during the Commercial Crew Program.
Crucially, a human-rated system must not only ensure crew safety but also accommodate their needs, provide control over the spacecraft’s operation, and offer mechanisms for manual intervention when necessary. For instance, NASA mandates that astronauts have manual control over Orion‘s flight path and attitude, alongside the ability to override software control and automation.
With that in mind, let’s take a look at Artemis I’s outcome…
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Orion’s heat shield was severely damaged
The unexpected behavior of Orion’s heat shield during reentry into Earth’s atmosphere poses a significant safety concern for future crewed missions. During Artemis I, over 100 instances of ablative thermal protective material chipping away unexpectedly were identified, creating potential risks for the crew and the spacecraft.
Despite the heat shield’s successful protection of the Crew Module and its systems during Artemis I, post-recovery inspections revealed unexpected variations in the appearance of the heat shield’s Avcoat ablative material. Portions of the char layer wore away differently than predicted, cracking and breaking off in fragments rather than melting away as intended.
This behavior raises concerns that the heat shield may not adequately protect the capsule and its occupants from the extreme heat of reentry in future missions, potentially affecting crew safety. The investigation into this anomaly led to the formation of a Tiger Team tasked with reproducing and modeling the char loss conditions.
While ground tests have successfully recreated the char loss phenomenon, they have not fully replicated the exact material response or flight environment experienced during Artemis I. Given Orion’s ~40% higher velocity compared to other spacecraft – like the SpaceX Crew Dragon – due to its longer return journey, engineers face challenges in understanding and mitigating the char loss phenomenon.
Senior NASA leaders, is said in the report, are committed to identifying the root cause of the issue and making informed decisions for Artemis II. However, they acknowledge the complexity of the task and the OIG expressed concerns for unintended consequences when implementing corrective measures, the so-called “residual risks”.
Without a thorough understanding of the effects of these modifications, ensuring the safety of future crewed missions remains a challenge for the National Space Agency.
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Bolts were melted and eroded
Post-flight examinations of the Crew Module/Service Module separation bolts following Artemis I uncovered troubling findings of unexpected melting and erosion, creating gaps that could lead to increased heating during reentry. These four bolts play a critical role, providing structural support for the attachment of the Crew Module to the Service Module.
During reentry, the bolts receive a separation command, allowing the Crew Module to detach and continue its descent, while the Service Module burns up in Earth’s atmosphere. However, during Artemis I, three out of the four bolts exhibited exposed gaps, leading to greater-than-anticipated melting and erosion.
This poses a significant risk, as excessive heating could compromise Orion’s structural integrity, potentially resulting in vehicle breakup and crew loss. NASA’s post-flight investigations revealed a discrepancy in the thermal model used to predict the bolts’ performance, suggesting that current predictions exceed Orion’s design capability.
To address this issue for Artemis II, minor modifications were made to the separation bolt design, and additional thermal protective barrier material was added to the bolt gaps. Furthermore, NASA is exploring adjustments to the Artemis II reentry trajectory to mitigate friction and heating on the bolts.
However, final assessments of the separation bolts cannot be completed until the investigation into the heat shield char loss concludes and the thermal model is updated to reflect Artemis II’s design changes.
Uncommanded power disruption
Throughout the Artemis I mission, NASA encountered 24 instances of uncommanded openings of the Power Conditioning and Distribution Unit (PCDU) Latching Current Limiters in the Service Module.
These PCDUs play a crucial role in delivering power to various spacecraft systems, including propulsion and pressurization. The uncommanded openings, akin to a circuit breaker tripping, disrupted power flow, affecting several components during one occurrence and compromising redundancy for safety-critical systems.
The investigation attributed these disruptions to radiation, prompting NASA engineers to implement flight software changes and operational workarounds to mitigate the risk for Artemis II.
However, the lack of a permanent hardware fix raises concerns that these systems may not perform as intended during the first crewed mission, potentially jeopardizing vehicle propulsion and pressurization.
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Even imaging cameras suffered failures
The limited collection of imagery, telemetry, and physical evidence during Artemis I has extended known risks to future crewed missions. This first mission faced numerous challenges with imagery, particularly during launch.
Furthermore, launching at night augmented these issues, as NASA encountered exposure problems with 32 out of 33 cameras, leading to under-exposed and misaligned images. Such imagery deficiencies hindered the identification of critical events like liftoff, ascent, and separation debris, essential for assessing vehicle integrity and crew safety.
For instance, engineers were unable to detect debris shedding events and accurately size debris due to the dark conditions and improperly adjusted camera equipment. This inability to collect vital data not only could impact mission success but also undermines efforts to mitigate long-standing risks, such as unresolved SLS booster throat plug debris which are ejected at ignition.
To address these challenges, the Exploration Ground System Program initiated corrective actions, including software changes, procedure updates, and additional training. However, OIG underlined in the report that the any additional corrective actions that could become needed may impact the program’s schedule for Artemis II.
Key hardware (like parachutes) not recovered
The inability to recover jettisoned hardware from the Orion capsule during Artemis I landing and recovery operations posed significant challenges for NASA, particularly concerning the recovery of key components like the main parachutes and the Forward Bay Cover. In fact, these components are vital for ensuring crew safety during landing, and failure of any of these systems can have catastrophic consequences.
Despite pre-flight preparations and analysis, the recovery team was unable to reach the splashdown location in time before the hardware sank in the Pacific Ocean, preventing post-flight inspections and physical assessments of their performance. Without the recovery and examination of these critical components, the Agency must rely solely on imagery to evaluate their performance, leaving certain details unclear.
To address this issue for future missions, the Orion Program managers are considering adding flotation capabilities to the jettisoned hardware, allowing for additional time for recovery teams to retrieve or inspect them for post-flight analysis.
The importance of physical inspection in understanding hardware performance and resolving anomalies has been demonstrated by NASA’s Commercial Crew Program, where unexpected parachute findings prompted design changes that would have otherwise gone unnoticed, without physical inspection of recovered hardware and imagery.
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New acceptance issues and NASA comment
Issues uncovered during qualification and acceptance testing of key Orion components, including circuitry and Crew Module batteries, have led to the decision to delay Artemis II to September 2025.
In August 2023, a hardware design deficiency was discovered in the circuitry controlling critical components of the Atmosphere Revitalization System, posing risks to crew safety due to potential high levels of carbon dioxide. Additionally, deficiencies in Crew Module battery performance were identified, potentially limiting spacecraft power during abort scenarios, increasing crew loss risks.
NASA is actively addressing these issues, including modifying circuitry hardware and conducting additional tests to ensure operability, while investigations into battery performance are ongoing.
NASA’s comment on the report is at the end of the document, and it’s pretty interesting, to say the least. Catherine Koerner, NASA’s Associate Administrator for Exploration Systems Development, is the one who wrote it:
“NASA is dedicated to continuous enhancement of our processes and procedures to ensure safety and address potential risks and deficiencies. However, the redundancy in the above recommendations does not help to ensure whether NASA’s programs are organized, managed, and implemented economically, effectively, and efficiently.
NASA remains committed to flying safely and looks forward to a successful Artemis II mission […].”
— Catherine Koerner, NASA’s Associate Administrator for Exploration Systems Development [from the OIG Report]
Basically, the report is not useful to improve the Artemis Program, NASA said. Not a common behavior by the agency, to say the least, but that’s it. In either case, we finally have a more comprehensive view on what went wrong during Artemis I.
NASA surely has some work to do in order to fly future missions safely, but a big question remains: is Artemis – as it stands now – the best program we could aspire to for returning to the Moon?
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