The European Space Agency (ESA) is an intergovernmental space organization that pools the budgets, talent, and industries of its European member states (with partners like Canada) to do science, Earth observation, navigation, telecom, and robotic exploration.
ESA builds its own launchers (Ariane, Vega), flies flagship science missions (e.g., Gaia, Euclid, Solar Orbiter, JUICE), operates the Columbus lab on the ISS, and follows a “geo-return” model that spreads contract work back to contributing nations—making space a pan-European industrial project.
# Comparison with NASA Compared with NASA, ESA is smaller in budget and doesn’t currently launch its own astronauts, but the agencies’ strengths are highly complementary. NASA leads large crewed programs and many outer-planet flagships; ESA contributes cutting-edge instruments, spacecraft, and key systems (from Huygens at Titan to the Orion service module), and runs world-class Earth-observation fleets that feed climate and environmental data globally.
Many marquee missions are joint: Hubble and JWST operations, Mars Sample Return elements, and parallel planetary probes (e.g., JUICE and NASA’s Europa Clipper) that together give a richer, cross-checked view of the Solar System.