The SLS Saga: 2023 Project Update
The Launch of Artemis I on November 16, 2022 (Courtesy of NASA)
“Ambition is the path to success. Persistence is the vehicle you arrive in.”
***The 2023 edition of the yearly update on the SLS Program. For related posts, please visit the SLS Saga microsite here***
As the new space race gains momentum, 2023 is poised to become the year that humanity refocused its attention back on the Moon. Numerous nations are racing ahead to secure their stake on humanity’s only natural satellite. The United States—having already achieved the historic feat of landing the first humans on our celestial neighbor—is determined not to fall behind. At the heart of America’s lunar exploration program is our old friend: the Space Launch System (“SLS”). So, as a longstanding tradition of the #TheSpaceBar blog, here are the latest significant developments since our last annual update as a part of my SLS Saga series.
SLS’s Affordability (September 2023)
At the forefront of this year’s update lies an issue that is widely acknowledged but only recently officially confirmed. It appears that NASA has admitted what many had quietly suspected all along (for example here and here): the SLS Program has become prohibitively expensive. This revelation came to light as part of a comprehensive analysis conducted by the Government Accountability Office (GAO) that scrutinized the cost of the SLS Program.
NASA’s senior officials candidly admitted to the GAO that the SLS Program had become “unaffordable.” Furthermore, this GAO investigation highlighted two key concerns that have contributed to this financial deterioration. First, NASA’s financial accounting methods for the development and production costs of the SLS Program appear to have been misguided. Second, the agency seems to have overlooked the substantial financial strain that will be caused by delays in the Artemis missions. While NASA did propose some cost-reduction strategies, the GAO remains skeptical about these mitigation plans’ feasibility and effectiveness in addressing the mounting affordability challenges of the SLS Program. These developments raise significant questions about SLS’s future and its role in NASA’s broader Outer Space exploration initiatives.
SLS’s Competitor Passes Engine Test (September 2023)
While the SLS Program is struggling with cost controls, SpaceX, the primary commercial contender to the SLS, passed a critical test in September. This test, related to its Raptor engines, has relevance on the collaborative Artemis III mission between the two competitors—one that hinges on both SpaceX's Starship and the SLS rocket. Specifically, these Raptor engines for the SpaceX’s Starship Human Landing System demonstrated its capacity to safely restart in the frigid vacuum of Outer Space. This capability is paramount for this Moon lander, which will likely endure long idle periods in Outer Space that can lead to a drop in its internal temperature. Without the ability to cold-start in Outer Space, the prospect of astronauts becoming stranded on the Moon would loom ominously.
Currently contracted as the provider of the Moon Landing system for Artemis III, SpaceX has emerged as a critical player in NASA's ambition to return Americans to the lunar surface—a feat that it has not accomplished since the Apollo era. While the astronauts will embark on their lunar journey aboard an Orion capsule launched via the SLS rocket system from Earth, a seamless transition to the Starship human landing system will be essential as they approach the lunar orbit. Thus, this collaborative effort between the SLS rocket and SpaceX's Starship is pivotal in ensuring the success of a historic mission, one that holds the potential to mark a significant milestone—landing the first woman on the Moon.
Engine Testing (October 2023)
On the topic of rocket engines, SLS is also in the midst of a significant update for its RS-25 engines. Thus, NASA is gearing up to begin a series of 12 certification tests on the new RS-25 engine design. This is set to take place at the Fred Haise Test Stand within NASA’s Stennis Space Center. These performance tests are designed to rigorously evaluate the performance of the updated RS-25 engines, simulating the conditions they will face during an actual SLS rocket launch.
Each engine will undergo an intense firing process that will last a minimum of 500 seconds, with the longest test extending to a duration of 650 seconds. Collectively, this battery of tests will accumulate a total hot fire test time of approximately 6,350 seconds. During these tests, NASA will vary the power levels of these engines within a range spanning from 80% to 113%. This variation in engine power will enable NASA to gather critical data regarding RS-25 engines’ performance under a spectrum of scenarios and conditions.
The wealth of data accrued during these comprehensive tests will be fed into the final certification review of this updated RS-25 engine design. Should these tests prove successful, 24 new RS-25 engines will be manufactured and poised for operational readiness by the launch of Artemis V. This milestone will not only mark a leap in engine technology but also will solidify NASA's commitment to advancing space exploration capabilities.
Engines Being Installed for Artemis II (September 2023)
In a related development related to the RS-25 engines, NASA marked a crucial milestone in September by successfully installing the first of four RS-25 engines needed for the upcoming Artemis II mission. This achievement follows the meticulous integration of all five major components of Artemis II’s SLS core stage that was completed in March of this year. Slated to become NASA’s first crewed mission to orbit the Moon since the Apollo era, Artemis II will represent a monumental step in NASA's renewed lunar exploration endeavors. This mission will carry a crew of four astronauts on an awe-inspiring journey around our celestial neighbor, marking the closest humans have come to the Moon since December 1972 when the Apollo 17 mission departed from the lunar surface.
The assembly of the SLS’s engines is being conducted at NASA's Michoud Assembly Facility which is nestled in the vibrant city of New Orleans. One interesting fact I learned about the RS-25 engines is that each one bears its own unique serial number. The recently installed engine, positioned in the number two slot, bears the serial number E2059. Remarkably, E2059—along with E2047 which will be installed in position one—were both used during the Space Shuttle era. In fact, E2047 boasts a storied history, having been a part of an impressive 15 space shuttle flights. Meanwhile, the final two engines, E2062 and E2063, are new but will have components that were previously flown. Thus, these engines represent the amalgamation of NASA's rich spacefaring heritage.
Artemis II’s Crew (April 2023)
On the topic of crewed missions, NASA formally revealed the four astronauts that will comprise the crew of Artemis II, SLS rocket’s next mission. Consisting of three remarkable men and one pioneering woman, this diverse and accomplished team represents the latest cream of the humanity’s crop. The Artemis II crew comprises NASA astronauts Reid Wiseman, Victor Glover, and Christina Hammock Koch, alongside Canadian Space Agency astronaut Jeremy Hansen. All astronauts will have their own role to play: Reid Wiseman will be commanding the mission while Victor Glover will take on the role of pilot; Christina Hammock Koch and Jeremy Hansen will both serve as mission specialists.
Notably, this crew will be a part of a historic mission as Artemis II will be NASA’s closest crewed return to the Moon in over fifty years and the maiden crewed endeavor of the Artemis Program as well as the inaugural crewed launch of the SLS Program. Originally designated Exploration Mission 2, Artemis II is slated for an approximate 10-day odyssey as it makes a round trip orbit around the Moon. Significantly, this mission will herald a host of firsts for a lunar mission: with the crew made up of the first woman (Christina Hammock Koch), the first person of color (Victor Glover) and the first Canadian (Jeremy Hansen) to embark on a lunar mission. Thus, as humanity's ambitions reach beyond near-Earth space, the Artemis II crew will serve as a beacon of inspiration, reflecting the inclusivity and diversity that define this new era of Outer Space exploration.
Larger Payload Adapters (August 2023)
As the Artemis II crew diligently prepare for their upcoming mission, NASA is concurrently focusing on hardware upgrades for the SLS rocket. Specifically, the agency is embarking on a project to enhance the payload capacity of the SLS rocket, with a particular emphasis on accommodating CubeSats of varying sizes. This initiative centers on the development of an advanced payload adapter capable of carrying CubeSats of varying dimensions. During the inaugural voyage of the SLS, Artemis I, though uncrewed, carried a payload of ten CubeSats, hailing from the original selection of thirteen. However, at that time, these CubeSats were exclusively of the 6U variety—measuring 10 by 20 by 30 centimeters—which represented the state-of-the-art for small satellites at the time.
In the ever-evolving landscape of space technology, CubeSats have become significantly more sophisticated. In response, the SLS team is brainstorming modifications to the payload adapter, broadening its capabilities to accommodate CubeSats of more varying sizes. This envisioned update will extend SLS’s deployment compatibility to CubeSats of 6U, 12U, and even 27U in size, unlocking a new realm of possibilities for scientific research and exploration. However, the implementation of this upgraded payload adapter is a long-term project. The current plan has Artemis V as the first mission to feature this enhanced payload feature.
