The Space Launch System (SLS) Block 1B rocket is a central component of NASA’s Artemis program, which aims to return humans to the Moon and eventually send crewed missions to Mars. Block 1B represents an important upgrade from the earlier Block 1 version of the SLS, increasing its cargo capacity by 40%. This capability will be critical for missions like Artemis IV, scheduled for September 2028, which will transport the Orion Multi-Purpose Crew Vehicle and large payloads, such as the International Habitation Module, to the Moon.
NASA has faced significant challenges in managing the development of the SLS Block 1B, particularly in the areas of cost control, schedule adherence, and quality management. The rocket’s new upper stage, the Exploration Upper Stage (EUS), developed by Boeing, has been a major source of these challenges. This article provides an in-depth examination of the issues NASA has encountered in overseeing the development of the SLS Block 1B, with a focus on the EUS and the associated cost, schedule, and quality management concerns.
The Development of the Space Launch System Block 1B
The SLS Block 1B, which has been in development since 2014, is intended to provide NASA with a more powerful heavy-lift rocket capable of sending larger payloads to the Moon. The key to this upgrade is the EUS, which will increase the SLS’s payload capacity from 27 metric tons (Block 1) to 38 metric tons (Block 1B). This enhanced capability is essential for future Artemis missions, which will require the transport of both crew and significant amounts of cargo to support lunar exploration and eventual human missions to Mars.
However, the development of the Block 1B has been fraught with difficulties. Originally intended for the Artemis II mission, the first flight of the Block 1B was postponed to Artemis IV due to delays in the development of the EUS and other components. These delays have been driven by a variety of factors, including changing technical requirements, competing funding priorities, and congressional directives to accelerate the development timeline.
The cost of developing the Block 1B has also increased significantly. Boeing’s contract for the EUS, initially valued at $962 million, has grown to over $2 billion, contributing to the overall cost increase for the Block 1B. As of 2024, NASA estimates that the total cost of the Block 1B development will reach $5.7 billion by the time of its first flight in 2028. This is $700 million more than the Agency Baseline Commitment (ABC) established in December 2023.
Quality Management Challenges at Boeing’s Michoud Assembly Facility
One of the key challenges NASA has faced in managing the development of the SLS Block 1B is ensuring that Boeing, the prime contractor for the EUS, adheres to industry-standard quality management practices. NASA requires its contractors to comply with SAE International’s AS9100D standards for quality management systems in the aerospace industry. However, Boeing’s quality management system at the Michoud Assembly Facility, where the EUS is being manufactured, has failed to meet these standards.
Between September 2021 and September 2023, the Defense Contract Management Agency (DCMA), which conducts quality assurance surveillance for NASA, issued Boeing 71 Corrective Action Requests (CARs) for quality deficiencies at Michoud. This is considered a high number of CARs for a space flight system at this stage in development and reflects significant weaknesses in Boeing’s quality control processes. The issues identified include foreign object debris contamination, stamp warranty violations, and welding defects on critical components like the liquid oxygen fuel tank dome.
One of the primary reasons for these quality control issues is Boeing’s lack of a sufficiently trained and experienced workforce at Michoud. The facility has struggled to attract and retain qualified aerospace technicians, leading to production delays and increased risks of nonconformances. Boeing has implemented training programs and work orders to address these challenges, but these efforts have been largely inadequate in mitigating the quality control deficiencies identified by NASA and DCMA.
Cost Increases and Schedule Delays in the SLS Block 1B Program
The development of the SLS Block 1B has been marked by significant cost overruns and schedule delays, many of which are attributable to the challenges associated with the EUS. The total cost of the Block 1B is now projected to reach $5.7 billion by 2028, well above the initial estimates. The cost of developing the EUS alone has increased nearly threefold, from $962 million to $2.8 billion.
Several factors have contributed to these cost increases and schedule delays:
- Redirection of EUS Funding: During the production of the Artemis I core stage, Boeing underestimated the complexity of the project, leading to cost overruns. To address these overruns, NASA redirected funding intended for the EUS to the core stage, causing delays in the EUS development timeline.
- Changing Mission Assignments: The Block 1B was initially planned for the Artemis II mission but was later reassigned to Artemis IV. This change in mission assignments, combined with delays in earlier Artemis missions, has disrupted the development schedule for the Block 1B.
- Workforce Challenges: The EUS workforce has been engaged in the project for a decade, and sustaining this workforce has added significant costs to the program. Boeing is expected to continue spending at high levels on workforce and contractor costs until the EUS is delivered to NASA in 2027.
- Manufacturing Issues: Boeing has experienced numerous manufacturing issues, particularly with welding operations at Michoud, which have resulted in costly rework and production delays. These issues have been compounded by supply chain challenges, including delays in sourcing critical components.
Given the delays in the EUS development and the challenges in meeting schedule milestones, there is a risk that the Artemis IV launch, currently planned for September 2028, could be delayed further.
Accountability and Transparency Issues in the SLS Block 1B Development
One of the significant challenges in managing the SLS Block 1B development has been the lack of transparency and accountability in cost and schedule reporting. Despite spending over $3 billion on the Block 1B since 2014, NASA did not establish a formal cost and schedule baseline (ABC) for the project until December 2023, 10 years into development. This delay in establishing a baseline has hindered NASA’s ability to monitor progress and control costs effectively.
In addition to the delayed baseline, NASA has faced challenges in obtaining accurate cost and schedule data from Boeing due to deficiencies in the contractor’s Earned Value Management System (EVMS). Boeing Defense, Space & Security, which is responsible for the SLS Stages contract, has had its EVMS disapproved by the U.S. Department of Defense (DOD) since 2020. This disapproved status has impacted NASA’s ability to use Boeing’s EVMS data to make informed decisions about the SLS Block 1B development.
DCMA has issued several Level II and III CARs related to Boeing’s EVMS deficiencies, including issues with maintaining accurate cost estimates and tracking schedule performance. These deficiencies have limited NASA’s visibility into the true cost and schedule risks associated with the Block 1B development. Although Boeing has begun implementing corrective actions, the issues with its EVMS are not expected to be fully resolved until late 2024.
Summary
The development of the Space Launch System Block 1B has been a complex and challenging process for NASA, with significant issues related to cost control, schedule adherence, and quality management. Boeing’s development of the Exploration Upper Stage has been particularly problematic, with substantial cost overruns, production delays, and quality control deficiencies. These challenges have been exacerbated by workforce shortages, manufacturing issues, and supply chain disruptions.
NASA has taken steps to address these challenges, including implementing new training programs at Boeing’s Michoud Assembly Facility and engaging with the Defense Contract Management Agency to improve quality assurance oversight. However, the SLS Block 1B development continues to face risks, particularly in meeting the schedule for the Artemis IV mission in 2028.
Looking ahead, it will be important for NASA to ensure that Boeing resolves its quality management issues and delivers the EUS on time and within budget. Additionally, NASA will need to improve transparency and accountability in its management of the Block 1B program by establishing clear cost and schedule baselines and addressing the deficiencies in Boeing’s Earned Value Management System. Failure to address these issues could jeopardize the success of future Artemis missions and NASA’s broader goals for human space exploration.
