Amentum

Amentum is an engineering and technical services company headquartered in Chantilly, Virginia, formed in 2020 out of AECOM’s management services business and substantially enlarged by its 2024 merger with Jacobs’ Critical Mission Solutions and Cyber and Intelligence units. The company works in nuclear, defence, environmental remediation, space and energy markets, with a large share of its revenue from government programme and project management rather than direct construction. Amentum is the sole programme and project management delivery partner on Sizewell C, the £38 billion twin-EPR nuclear station being built on the Suffolk coast, where peak construction workforce is projected at roughly 10,000. It also supports nuclear decommissioning programmes for the U.S. Department of Energy.

Amentum’s clearest foothold in space work is at Kennedy Space Center, where the company is the prime contractor for NASA’s Exploration Ground Systems Program supporting the Artemis effort to return astronauts to the Moon, including plans for the first woman and first person of color to walk on the lunar surface. That contract covers development, integration, and operations of flight vehicle components — assembly, integration, testing, launch, and recovery — rather than a narrower support role. The company’s own site frames Artemis as part of a broader space capability that also touches civilian space and defense and national-security space markets as separate lines of business.

Space is only one of six capability areas Amentum organizes its work around: Mission Modernization & Sustainment, Space Systems, Digital Transformation, Sustainability & Environment, Advanced Energy, and Data Analytics and Cyber. That last category includes biometrics integration work for the Department of Homeland Security, where the company says it applies training and commercial best practices across roughly 130 USCIS locations nationwide, plus cybersecurity training programs built around scenario-based exercises rather than classroom instruction alone. Geographically, the company organizes its market pages around the US, UK, and Australia specifically, alongside broader defense, intelligence, and civilian government segments.

By its own count, Amentum employs approximately 50,000 people across more than 70 countries on all seven continents, a scale reflected in the recognitions it lists on its site: a Military Friendly Employer designation, U.S. Green Building Council membership, VPPPA participation, and coverage from Newsweek and Washington Technology. Its social presence is narrow compared with a typical contractor on this directory — a single X account, @amentum_corp, and a LinkedIn page, rather than the consumer-facing Instagram or Facebook accounts smaller trade businesses tend to run — which tracks with a customer base built almost entirely around government agencies and prime contract holders rather than individual property owners.