NASA’s Space Launch System rocket launches carrying the Orion spacecraft launched at 6:35pm EDT on April 1, 2026 - Image Credit: NASA/Bill Ingalls
Legacy Hardware, Brownfield Design, and Why Artemis Costs So Much
I was 12 years old in July of 1969. I was in the family farm's bunkhouse, and heard on the radio that Apollo 11 was about to land. I decided to join my family at the main farmhouse and watch it on our 13-inch black-and-white TV. It was raining hard, so I hopped on my bike to cross the few hundred yards more quickly. Halfway there, next to the milking parlor, I took a spill right into a mud puddle. Drenched and muddy, I walked my bike the rest of the way. Still wet, I was able to join the family to watch the moon landing. It's hard to describe how proud we all were, not being just Americans but being part of mankind. That as a species we were able to accomplish such an amazing feat.
But after 4 years, 11 crewed missions, and six successful Moon landings, the program was canceled because it took over 4% of the federal budget, and we had more immediate earthly concerns. [1] Bottom line: it's good to have great ambitions, but it has to be tempered with the reality of funding and other priorities.
Now here we are, 54 years later, attempting to repeat our previous success. And you might reasonably ask: if we did it before, with slide rules and computers with less processing power than the phone in your pocket, why is it taking so long and costing so much? The answer has almost nothing to do with technology. It has to do with what happens when you tell your engineers they have to build something new out of something old.
The INCOSE Systems Engineering Handbook, Fifth Edition, borrows a term from real estate to describe this situation. It distinguishes between "greenfield" systems (the blank sheet of paper on which you start fresh) and "brownfield" systems (previously developed land with existing structures, potentially containing "undesirable or hazardous materials that must be remediated"). [2] The handbook uses "legacy" and "brownfield" interchangeably, and the metaphor of contaminated land is more apt than I think the authors intended.
When the handbook defines brownfield SE, it says the
new system architecture "must take into account the existing system elements and functions, which impose constraints on the overall system definition." [3]
That word "constraints" is doing a lot of work here. It means your design space has been pruned before you pick up a pencil, not by physics or mission requirements, but by decisions someone else made for a different system decades ago.
The Space Launch System is the most expensive case study in brownfield design constraint our industry has ever produced. The 2010 NASA Authorization Act directed NASA to use existing Space Shuttle and Constellation program contracts, hardware, and workforce "to the extent practicable." [4] In practice, the RS-25 engines, solid rocket boosters, 8.4-meter tank tooling, and the workforce that maintained all of it were mandated design inputs. A design constraint is not inherently bad. Constraints make engineering interesting. But these constraints were derived from the political need to preserve an industrial base, not from the physics of getting to the Moon. The constraint source matters.
The handbook warns about exactly this. It identifies "serious traps" in reuse: Was the prior solution intended for a different use or environment? Trap. Is the new application outside the qualified range? Trap. It even provides an example of a NASA Mars probe that failed because the team reused a radiator designed for Earth orbit without recognizing the different thermal environment. [5] The RS-25 engines are another case in point. Magnificent engines designed to be reusable, now thrown away after a single SLS flight. And with only sixteen remaining from the Shuttle program [6], the design was locked into a finite, dwindling supply of its own propulsion.
RS-25 developmental engine at the Fred Haise Test Stand at NASA’s Stennis Space Center
The cost numbers need little embellishment. SLS took thirteen years and roughly $23 billion to develop. [7] Total Artemis vehicle costs have reached approximately $61 billion. [8] Each launch costs around $4.1 billion. [9] And a Booz Allen Hamilton analysis found that using legacy hardware actually cost more than new development would have. [10] The whole rationale was to save money. The result was higher costs than a clean-sheet design.
Now set that next to SpaceX. No legacy mandate, no Congressional parts list. SpaceX developed the Falcon 9 from a blank sheet in four and a half years for just over $300 million. [11] NASA's own models estimated that same rocket would have cost $1.7 to $4 billion through traditional contracting. [12] When Congress asked why, the answer was simple: NASA set "only a high-level requirement for cargo transport to the space station, leaving the details to industry." [13] They defined what the system needed to do and let engineers figure out how. SpaceX's Starship tells a similar story, pivoting from carbon fiber to stainless steel when the material better served their design goals. [14] That kind of architectural pivot is impossible in a brownfield-constrained program.
The Falcon 9 has completed over 620 successful launches. [15] SLS has flown twice. In February 2026, NASA cancelled the planned Block 1B and Block 2 upgrades, acknowledging the evolutionary path was unsustainable. [16] Even the Europa Clipper, originally mandated for SLS, was competitively bid and won by SpaceX, saving $2 billion. [17]
SpaceX Falcon 9 Launch Through the Clouds
The handbook observes that organizations accustomed to brownfield development may need to "relearn" greenfield. [18] Legacy doesn't just constrain your current design. It atrophies your capacity to think beyond the constraints. You stop asking "what's the best solution?" and start asking "how do we make the old stuff work?" Those are fundamentally different questions.
The Saturn V was a greenfield design. The engineers at Marshall Space Flight Center were given a destination, not a parts list. They got there in eight years for about $200 billion in today's dollars. [19] Expensive, yes. But they were solving the problem they were given, not the problem of what to do with leftover hardware.
Legacy is first and foremost a design problem. It constrains your architecture, limits your trade space, introduces technical debt you didn't incur, and creates the seductive illusion that because development has already been done, the path forward should be easier and cheaper. The question for practitioners is whether we're honest about the true cost of those constraints, or whether we let sunk cost masquerade as a head start.
My twelve-year-old self, the one who fell off his bike in the rain to watch history happen on a tiny television, would probably be disappointed that it took us this long to go back. But my systems engineering self understands exactly why. We weren't just trying to get to the Moon again. We were trying to get to the Moon while dragging the Space Shuttle behind us.
Here's a question: Are the legacy constraints in your program derived from the mission need, or from something else?
Optional Reader Resource
References
Wikipedia, “Apollo Program.” https://en.wikipedia.org/wiki/Apollo_program
INCOSE Systems Engineering Handbook, Fifth Edition (INCOSE SEH5), Sec. 4.3.1: Greenfield/Clean Sheet Systems.
INCOSE SEH5, Appendix C: Terms and Definitions, “Brownfield SE.”
U.S. Congress, NASA Authorization Act of 2010, S.3729, Sec. 302.
INCOSE SEH5, Sec. 2.3.3: Technical Management Processes, Knowledge Management subsection.
Wikipedia, “Space Launch System,” https://en.wikipedia.org/wiki/Space_Launch_System. Accessed April 2026.
SpaceX Stock, “SpaceX vs. NASA: Structural Design Approaches,” July 2025. https://spacexstock.com/spacex-vs-nasa-structural-design-approaches/
Payload Space, “Detailing Artemis Vehicle R&D Costs,” March 2024. https://payloadspace.com/payload-research-detailing-artemis-vehicle-rd-costs/
Aerospace America (AIAA), “Bending the Cost Curve,” April 2025.
NASA Fandom Wiki, “Space Launch System,” citing PopularMechanics analysis. https://nasa.fandom.com/wiki/Space_Launch_System
National Space Society, “Statement on Launch Costs from SpaceX CEO Elon Musk,” May 2011. https://nss.org/statement-from-spacex-ceo-elon-musk/
New Space Economy, “How much would Falcon 9 have cost if it was developed by NASA?” May 2023. https://newspaceeconomy.ca/2022/10/23/how-much-would-falcon-9-have-cost-if-it-was-developed-by-nasa/
Wikipedia, “Falcon 9,” https://en.wikipedia.org/wiki/Falcon_9. Accessed April 2026.
Productside, “Behind The Product: NASA SLS vs. SpaceX Starship,” April 2022. https://productside.com/behind-the-product-nasa-sls-vs-spacex-starship/
Wikipedia, “Falcon 9.” Accessed April 2026.
Hacker News discussion, November 2024. https://news.ycombinator.com/item?id=42070547
Wikipedia, “Space Launch System.” Accessed April 2026.
INCOSE SEH5, Sec. 4.3.1: Greenfield/Clean Sheet Systems.
Inflation-adjusted estimate based on commonly cited Apollo program total costs.
