NASA is gearing to land humans on the moon for the first time since 1972 under the Artemis program; however, a recent report by the GAO reveals significant challenges that may impede the planned Artemis III crewed lunar landing in 2025.
The National Aeronautics and Space Administration (NASA) is gearing to land humans on the moon for the first time since 1972 under the Artemis program; however, a recent report by the Government Accountability Office (GAO) reveals significant challenges that may impede the planned Artemis III crewed lunar landing in 2025.
Since the GAO's September 2022 report, NASA and its contractors have made commendable progress in the Artemis III mission. Several crucial milestones have been completed, but the focus of the GAO report centers on persistent challenges with the development of the Human Landing System (HLS) and space suits.
The GAO's report indicates that despite progress the delays and challenges in the HLS program and space suit development are contributing factors, and a Artemis III crewed lunar landing is unlikely to happen in 2025.
GAO deems this timeframe unrealistic, emphasizing that if development aligns with the NASA project average, the Artemis III mission would likely occur in early 2027.
The ambitious schedule of the SpaceX Human Landing System program was set for 79 months from project start to launch, which is 13 months shorter than the average for NASA major projects.
As of September 2023, the Human Landing System program has experienced delays in eight of its 13 key events, with two events being pushed into 2025.
The delays are attributed in part to issues during the Orbital Flight Test, causing a setback and reliance on a successful second test for subsequent progress.
The Orbital Flight Test was delayed by 7 months to April 2023. It was then terminated early when the vehicle deviated from its expected trajectory and began to tumble. SpaceX has since conducted a 2nd Orbital Flight Test and are reviewing the data. Subsequent tests rely on a successful Orbital Flight Test.
SpaceX faces a substantial amount of technical work to support the Artemis III lunar landing mission, including the development of propellant transfer capabilities in orbit.
Limited progress in maturing these technologies raises concerns about meeting mission requirements and timelines.
- Raptor Engine Development - SpaceX plans to utilize the Raptor engine in both the lander and booster stages of the human landing system (HLS). The company considers the technology relatively mature due to extensive prior development. However, the HLS Program Office identifies engine development as a top risk. SpaceX employs an iterative approach in designing the Raptor engine and, as of September 2023, has assembled and tested numerous engines.
There is a concern that if the Raptor engine does not meet performance requirements, potentially delaying certification, the new main engine for the HLS might not be ready to support the planned mission in December 2025, as stated in a February 2023 interview with HLS officials.
- On-Orbit Propellant Transfer Technology - SpaceX faces remaining technical challenges in developing on-orbit propellant storage and transfer technology for the Human Landing System (HLS).
The program documentation highlights that these technologies have not been integrated into a propulsion-like system before, and SpaceX has made limited progress in their maturation. Key systems include docking sensors and mechanisms, propellant measurement, and storage capability to prevent fuel loss in space. SpaceX plans an in-space Propellant Storage and Transfer test, contingent on the success of preceding flights.
Although the fundamental technology isn't new, it requires significant engineering and testing efforts. If the docking hardware underperforms during testing, substantial vehicle modifications may be needed, potentially delaying the Artemis III mission.
Despite SpaceX and NASA's goal to accelerate development, key events in the HLS program are progressing more slowly.
Reaching the Preliminary Design Review (PDR) took SpaceX over 50% of its total schedule, while NASA major projects averaged about 35%. Additionally, the HLS program is lagging in reaching the Key Decision Point C (KDP C), the subsequent crucial review after PDR, compared to other NASA major projects.
Compounding the challenges, the HLS program is moving forward with development without formal approval of a cost and schedule baseline; planning to use nearly 14% more of its total schedule to progress from PDR to KDP C, whereas the average for NASA major projects is only 4.2%.
As a consequence of these delays, SpaceX aims to complete eight crucial events between November 2023 and the planned date of Artemis III.
The delays have resulted in a compressed timeline for NASA to ensure HLS compliance with human spaceflight safety requirements before the mission begins. Notably, the HLS Design Certification Review, originally planned further in advance, is now closer to the Artemis III mission. This review, scheduled 9 months before launch, is crucial for ensuring design compliance and human spaceflight certification.
Flight Readiness Reviews for the depot, tanker, and lander versions of the Starship were also initially planned within the same 9-month period before Artemis III.
Any additional delays to these events will intensify the schedule pressure on both NASA and SpaceX, limiting the time available to address issues identified during these reviews before the mission's
Axiom Space is tasked with developing modernized space suits and have encountered design challenges which will require resolution before the Artemis III mission.
Axiom Space Spacesuit Remaining Work
- Emergency Lift Support Required By NASA - NASA has mandated that Axiom develop an advanced spacesuit capable of providing a record-breaking 60 minutes of emergency life support. Axiom is facing challenges as the government reference design from NASA doesn't meet the requirement for storing the necessary amount of oxygen.
Axiom are considering redesigning portions of the suit, particularly the life support system package. This may involve shrinking the size and reorganizing components to accommodate larger oxygen tanks. Alternatively, if this proves unfeasible, Axiom is prepared to modify the existing life support system, although this would entail additional time.
- Parts Obsolescence + Improvements - Axiom have outlined their plans to incorporate, design, and certify new technologies, such as batteries, pumps, and electronic components, to address supply chain and obsolescence issues. They emphasize the importance of designing modular space suits, allowing the integration of new technologies to meet mission-specific requirements and facilitate incremental system upgrades.
Axiom is actively modifying all three sub-systems of their space suits: Power, Avionics, and Controls; Pressure Garment System; and Life Support System.
The company is also enhancing the government reference design, with a focus on the less mature heat exchanger component. Despite being in the early stages, Axiom reports superior performance in their heat exchanger through testing compared to the government reference design.
Axiom is developing its own evaporative fibers for the space suit water membrane evaporator, showing promising results that NASA has yet to independently assess.
These component modifications may require additional testing for maturity, pending NASA's assessment of the proposed fibers.
- Mature Critical Technologies - Axiom, in its mission to meet NASA requirements, aims to mature critical technologies, such as the Life Support System and Pressure Garment System.
As of January 2023, NASA evaluated these systems at Technology Readiness Level (TRL) 4. Axiom's assessment revealed that over half of its critical technologies were below TRL 6, with the Regenerable CO2 Scrubber rated at TRL 3 due to deviation from the government reference design.
NASA expects critical technologies to reach TRL 6 by the August 2024 Critical Design Review (CDR). However, as of May 2023, both the life support and pressure garment systems had not significantly advanced since January 2023. Axiom plans to conduct a Crew Capability Assessment for the pressure garment system before the November 2023 Preliminary Design Review (PDR). Human testing of the life support system is scheduled for CDR in a NASA vacuum chamber facility.
To mitigate supply chain risks, Axiom plans to produce some components in-house. However, NASA officials caution that using a different source may decrease TRL, requiring reassessment due to uncertainties associated with a new manufacturer. Components with design changes are also rated at a lower TRL and must be matured for use in the Artemis III mission.
Axiom personnel are actively developing multiple test rigs for various life support system components to support technology maturation efforts.
- Procure Suit Components - Axiom faces potential delays in developing and procuring components for space suits, risking the compression of its delivery window to NASA to less than 2 years by September 2025.
Critical components, particularly those supporting the life support system, have long lead times of 12-18 months for procurement. Axiom plans to outsource certain parts, like oxygen regulators, due to limited specialized suppliers.
Procuring components for the life support system is crucial for Axiom's schedule, with complex and specialized parts requiring qualification and acceptance testing upon delivery. To mitigate supply chain issues, Axiom now produces 40 out of 61 parts in-house, enhancing control over design and schedule.
- Qualify The Suit For Flight - Axiom is responsible for qualifying space suits for flight readiness before crew use, but potential issues with testing facilities may impact the timeline for the Artemis III mission.
Axiom initially planned a crew capability assessment at NASA's ARGOS facility in November 2023, but equipment issues led to a shift to the Partial Gravity Simulator facility in October 2023. Axiom is also preparing supporting documentation for this facility. Moreover, a vacuum test for the space suit will be conducted at another NASA facility during the Critical Design Review (CDR) phase.
- Lander Software + Hardware Integration - The HLS program is grappling with a significant cross-program risk associated with integrating its software and hardware with the Orion program.
The HLS system utilizes software spread across various hardware systems, making comprehensive end-to-end software testing on flight-like hardware in mission-relevant environments challenging. To address this, HLS risk management officials emphasize the necessity of emulators and simulators for joint verification testing with the Orion program.
Although agreements have been made between the Orion and HLS programs to share emulator and simulator hardware and software, concerns have arose in July 2023. NASA documentation reveals that the HLS development pace is not aligning with Orion program integration milestones, potentially jeopardizing the planned December 2025 launch readiness date.
The integration of software developed for diverse hardware platforms, operating systems, and heritage software poses challenges and the risk of introducing defects. HLS risk documentation underscores the need for adequate test facilities and campaigns to avoid late discovery of critical software defects during integration and testing with flight hardware. The absence of thorough testing may lead to missed critical software defects, resulting in potential cost overruns, schedule delays, or, in the worst-case scenario, mission or crew loss.
The HLS program has drawn insights from the Starliner first Uncrewed Flight Test by Boeing, which failed due to software issues, emphasizing the importance of increasing resources dedicated to software insight and oversight. These lessons learned have been incorporated into guidelines for NASA personnel to evaluate SpaceX-provided data on software development, aiming to identify defects earlier in the development process.
- Lunar Dust Contamination - NASA's Artemis III program, involving offices such as HLS, EHP, and Orion, are actively addressing the risk of lunar dust intrusion which poses potential hazards to both crew members (inhalation causing respiratory irritation and direct contact leading to eye irritation) and equipment (adversely affect system performance). Failure to mitigate this risk early in the design process may result in increased costs and retrofitting delays.
Various components of the program are independently working on limiting dust exposure.
The HLS program is testing cleaning techniques for lander hatches, Axiom Space is developing tools to clean space suits post-moonwalk, and SpaceX aims to demonstrate the HLS Starship's capability to maintain lunar dust at an acceptable level for crew health.
Despite individual efforts to meet dust contamination requirements, there remains a residual risk of crew injury or illness.
The Moon to Mars Program Office, overseeing the integration of all Artemis III systems, is actively addressing performance and safety risks associated with lunar dust, drawing on lessons learned from the Apollo mission and subsequent research. Collaboration with other NASA programs has led to the development of a long-term mitigation plan by the HLS program, focusing on enhancing knowledge of south pole lunar dust and its properties.
In response to these challenges, NASA plans to take multiple steps to ensure SpaceX's and Axiom Space's systems meet mission needs and crew safety standards. This includes a supplemental process not required by policies to assess contractors' systems before the mission and insight clauses in contracts providing visibility into crucial aspects of development work.
NASA's Artemis Campaign Development Division has unveiled an implementation plan outlining the strategy for Artemis missions. The plan highlights the scheduled technical and programmatic reviews.
Following individual program design certification reviews, there will be an additional review focusing on the integrated architecture requirements for Artemis III. This assessment will evaluate the ability of the combined HLS, EHP, Orion, SLS, and EGS systems to meet requirements across various configurations and environments.
NASA will undergo a certification of flight readiness process to ascertain the preparedness of these programs for executing the mission, with the exact details of this process yet to be determined.
As NASA faces many hurdles in the Artemis III mission timeline, the agency remains committed to overcoming challenges, emphasizing safety and mission success.
The GAO report underscores the need for careful consideration of development timelines, technical challenges, and ongoing oversight to achieve the ambitious goals set for the Artemis program.