The Space Launch System (SLS), a critical component of NASA's plans to return astronauts to the Moon under the Artemis program, is facing significant scrutiny and potential cancellation. The Trump administration has proposed discontinuing the SLS after just three launches, while a preliminary bill moving through Congress suggests extending its operational timeline to five flights. However, experts believe that the SLS may struggle to reach even nine flights before 2040, if at all.
As the White House pushes for the termination of the SLS program in favor of more economical commercial space alternatives, the future of the rocket remains precarious. NASA recently conducted two significant test firings of new propulsion hardware essential for the SLS's survival. This included a groundbreaking test of a new liquid-fueled RS-25 engine at NASA's Stennis Space Center in Mississippi, marking the first new engine of its kind manufactured since the conclusion of the Space Shuttle program.
During the test firing, which took place last Friday, the hydrogen-fueled RS-25 engine, designated for the fifth flight of the SLS — known as Artemis V — successfully ignited. Additionally, on Thursday, NASA and Northrop Grumman conducted a test of a new solid rocket booster in Utah, designed to enhance the performance of the SLS starting with the ninth mission, or Artemis IX. Unfortunately, this booster test experienced complications when the motor's exhaust nozzle shattered just under two minutes into the burn, resulting in debris scattering across the test area.
Since the inception of the SLS program nearly 15 years ago, NASA and its congressional supporters have promoted the rocket as a cornerstone for deep space exploration. They claimed that utilizing recycled space shuttle engines and boosters would expedite the SLS's development at a lower cost. However, the reality has fallen short, with each Artemis mission costing approximately $4.2 billion per flight, despite using existing shuttle-era technology.
With the remaining shuttle parts expected to deplete, NASA has initiated contracts with Aerojet Rocketdyne to produce new RS-25 engines. In 2015, NASA signed a deal to kickstart this production, ordering an initial batch of six engines, later increasing the order to 24 engines by 2020. While efforts are underway to reduce the cost per engine to $70 million, this figure remains significantly higher than comparable engines like Blue Origin's BE-4 or SpaceX's Raptor.
The recent test of the RS-25 engine was a noteworthy milestone, as it marked the reactivation of the production line after a decade-long hiatus. L3Harris, which acquired Aerojet Rocketdyne earlier this year, confirmed the engine's assignment to the Artemis V mission. The engine demonstrated impressive performance during a 500-second acceptance test, exceeding its rated thrust and showcasing advancements in manufacturing techniques.
NASA's recent solid rocket booster test was the first under the Booster Obsolescence and Life Extension (BOLE) program, which aims to develop a more powerful booster for future SLS missions. While the test initially seemed successful, the booster experienced a critical failure, leading to the destruction of its nozzle during the test burn. This incident raises concerns about the reliability of new booster designs as NASA moves forward with the Artemis program.
As NASA navigates the complex landscape of funding, technology development, and strategic direction, the fate of the Space Launch System hangs in the balance. With significant taxpayer investments already made, the agency must demonstrate the viability of the SLS as a cornerstone for lunar exploration. As discussions continue in Congress and within the administration, the future of NASA's ambitious lunar plans remains uncertain.
