International Space Station

The International Space Station (ISS), managed by NASA, is governed by a federal statutory framework that establishes U.S. policy for the station's use, research priorities, and long-term operation. Federal law designates the U.S. segment as a National Laboratory, requires minimum research budget allocations for life and microgravity science, mandates operation through at least 2030, and prohibits military use of the civil space station.

Current Law (2026)

Key Numbers

• Total cost: the ISS is the most expensive structure ever built, with total investment exceeding $150 billion (NASA's share approximately $100 billion, with partner contributions from Russia, ESA, JAXA, and CSA); U.S. annual operating costs run approximately $3-4 billion/year
• Continuous occupancy: continuously inhabited since November 2, 2000 — over 24 years — making it the longest continuously crewed space station in history; more than 270 people from 21 countries have lived on the ISS
• Research portfolio: the ISS National Laboratory has supported approximately 3,000+ experiments from over 100 countries since the National Laboratory designation; CASIS selects approximately 100-150 new experiments/year from federal agencies, universities, and commercial users
• Decommissioning contract: NASA awarded SpaceX an $843 million contract (2024) for a US Deorbit Vehicle to safely guide the ISS into a controlled Pacific Ocean reentry in approximately 2030; the station weighs approximately 900,000 pounds — safe controlled deorbit requires precise thrust sequencing to hit the "spacecraft cemetery" near Point Nemo
• Commercial successor investment: NASA has committed more than $2 billion to three commercial space station development programs — Axiom Space, Sierra Space/Blue Origin's Orbital Reef, and Nanoracks/Voyager's Starlab — to replace ISS for research and commercial users after 2030

Legal Authority

• 51 U.S.C. § 70901 — Peaceful uses (no civil space station may carry weapons of destruction or be used for military purposes — establishes the ISS as an exclusively peaceful facility)
• 51 U.S.C. § 70902 — Research budget allocation (NASA must allocate at least 15% of ISS research funds to ground-based, free-flyer, and ISS-based life and microgravity science, with priority for research benefiting humans in space)
• 51 U.S.C. § 70903 — ISS research (directs NASA to carry out microgravity research and consider life sciences capabilities)
• 51 U.S.C. § 70904 — ISS completion (U.S. policy to achieve diverse and growing utilization; NASA must ensure full operational capability with emphasis on research capacity)
• 51 U.S.C. § 70905 — National Laboratory designation (designates the U.S. segment as a National Laboratory, allowing other federal agencies, educational institutions, and private entities to use ISS research facilities)
• 51 U.S.C. § 70906 — National Laboratory Advisory Committee (establishes a FACA advisory committee to advise on management of the ISS National Laboratory, including research priorities and access policies)
• 51 U.S.C. § 70907 — Maintaining use through at least 2030 (directs NASA to take all necessary steps to ensure the ISS remains viable and productive through at least 2030)

How It Works

The ISS statutory framework addresses three fundamental questions: what the station can be used for, how its research resources are allocated, and how long it must operate.

The peaceful use restriction is absolute: the civil space station may not carry weapons of destruction or be used for military purposes. This provision reflects both U.S. space policy and international commitments under the ISS partnership agreements with Russia, Europe, Japan, and Canada. The restriction ensures the ISS remains a scientific facility, not a military platform.

Research allocation rules protect the station's scientific mission from being crowded out by operational and engineering needs. Congress mandated that at least 15% of the ISS research budget go to life and microgravity science — the fundamental research that justifies the station's existence. Within that allocation, priority goes to research that benefits humans living and working in space, reflecting the station's role as a testbed for long-duration spaceflight.

The National Laboratory designation was transformative. By designating the U.S. segment as a National Laboratory, Congress opened the station to users beyond NASA — other federal agencies (NIH, DOD, DOE), universities, and private companies. The Center for the Advancement of Science in Space (CASIS) manages National Laboratory access, selecting experiments and allocating crew time and research volume. This opened the ISS to pharmaceutical research, materials science, Earth observation, and commercial experiments that NASA alone might not have prioritized.

The 2030 operational mandate provides planning certainty. NASA must take all necessary steps to ensure the station remains viable and productive through at least 2030, preventing premature decommissioning and protecting the investment of the U.S. and its partners. The Advisory Committee provides external guidance on how to maximize the station's remaining productive years.

How It Affects You

If you're a researcher or biotech company interested in microgravity research: The ISS National Laboratory is genuinely open to outside researchers — not just NASA employees or traditional aerospace contractors. The Center for the Advancement of Science in Space (CASIS) manages access and provides free-flight opportunities on a competitive basis. Protein crystallization in microgravity produces larger, more perfect crystals than Earth-based methods, enabling high-resolution structural studies of drug targets — companies like Merck and Eli Lilly have used this for pharmaceutical R&D. Combustion science, materials processing, Earth observation, and long-duration human physiology research all have active ISS programs. If you have a research question requiring microgravity, CASIS's National Lab user guide at issnationallab.org is the starting point; proposals are reviewed quarterly and crew time is genuinely limited, so the competition is real.

If you're a taxpayer or policy observer evaluating the ISS investment: The ISS cost approximately $100 billion in U.S. funds over 30 years — roughly $3 billion/year — making it one of the most expensive single science programs in history. The statutory 15% research budget mandate and National Laboratory designation were Congress's attempt to ensure taxpayers got scientific and commercial returns proportionate to that investment. The $843 million deorbit contract adds to the total. Whether the ISS delivered commensurate value is genuinely debated: supporters point to advances in protein crystal research, human spaceflight physiology, Earth observation, and — most tangibly — the commercial cargo and crew industry it anchored (SpaceX's Dragon, now a multi-billion-dollar commercial business); critics note many research goals could have been achieved more cheaply. This debate matters now because Congress is deciding how much to invest in commercial successors.

If you work for a commercial space company: The ISS was the anchor customer that made commercial cargo and crew transportation economically viable. SpaceX's Falcon 9/Dragon cargo missions, which began in 2012, would not have had a business case without guaranteed NASA ISS resupply contracts. The Commercial Crew Program (Crew Dragon, Starliner) followed the same template. This public-private model — NASA paying per-mission rather than owning infrastructure — is now the template for post-ISS commercial station development. If you're working on a commercial station successor (Axiom, Orbital Reef, Starlab), the ISS's 24-year operating experience — what research users actually need, what operational constraints are deal-breakers, how to price station time — is the most valuable competitive intelligence available in the industry.

If you're an educator or student: Student experiments fly to the ISS through programs including the Student Spaceflight Experiments Program (SSEP), DreamUp, and NASA's CubeSat Launch Initiative. A K-12 or university student experiment can cost as little as $10,000-20,000 to get to orbit through these programs, compared to tens of millions for traditional satellite missions. Astronaut video calls with classrooms — through NASA's education programs — are available to K-12 schools with a relatively simple application process. If you're a science teacher or university faculty member, the Space Grant Consortium network in your state (all 50 states have a consortium) connects you to NASA education programming including ISS access opportunities.

State Variations

The ISS is exclusively a federal program under NASA. There are no state variations. However, Space Grant consortia in many states support ISS-related research and education activities. See also National Science Foundation for complementary STEM research funding.

Implementing Regulations

ISS operations are governed by intergovernmental agreements and NASA-partner agency MOUs rather than CFR. 14 CFR Part 1200 series contains NASA general provisions. ISS crew operations follow NASA procedural requirements and international partner agreements.

Pending Legislation

No standalone ISS legislation pending in the 119th Congress. ISS authorization is typically handled through NASA authorization acts.

Recent Developments

The Boeing Starliner saga left two astronauts stranded for 9 months and significantly reshuffled ISS crew transportation plans. Starliner's first crewed flight (June 2024) was marred by helium leaks and thruster problems; NASA ultimately decided the risk of a crewed return was too high and sent Butch Wilmore and Suni Williams home on SpaceX Crew Dragon in March 2025 after a 9-month unplanned ISS stay. Boeing's future in crewed spaceflight is uncertain; the incident cemented SpaceX's dominant position as the reliable ISS crew transportation provider. The episode also highlighted the statutory issue of crew transportation resilience — the 2030 operational mandate implicitly requires a reliable crew transportation capability, and single-vendor dependency on SpaceX is now a policy concern.

The 2030 decommissioning plan is taking concrete form. NASA's $843 million SpaceX Deorbit Vehicle contract (awarded 2024) is designed to safely guide the station into a controlled Pacific Ocean reentry — likely targeting Point Nemo (the oceanic pole of inaccessibility), the traditional graveyard for large space hardware. The deorbit is technically complex: the ISS is approximately the size of a football field and weighs 900,000 pounds; ensuring it breaks up and the fragments fall within a safe ocean zone requires precise planning starting years in advance. NASA is conducting structural assessments to verify the station can safely operate until the planned deorbit window while CASIS continues maximizing National Laboratory utilization in the remaining years.

Commercial space station development is the major post-ISS challenge — and a genuine business model risk. NASA's $2+ billion in commercial LEO destination awards went to Axiom Space (already flying commercial modules attached to the ISS), Sierra Space/Blue Origin's Orbital Reef, and Nanoracks/Voyager's Starlab. The commercial model requires these stations to attract paying customers beyond NASA — biotech firms, materials manufacturers, space tourism, national security users — to be financially viable without full government subsidy. Whether enough non-NASA demand exists to sustain multiple commercial stations' economics is the fundamental question the industry hasn't yet answered. The ISS's 24 years of experience shows what research users need; whether commercial market demand can meet the revenue requirements of privately financed orbital real estate is 2030's open question.