After the formalization of an agreement between Croatia and ESA, the agency established formal ties to all EU Member States that were not already ESA members. The EU Agency for the Space Programme (EUSPA) is the EU’s counterpart to ESA, and the two groups hold regular Space Council meetings, similar to the U.S. National Space Council, to identify key programmatic goals and develop an overall coherent strategy for the advancement of space activities in Europe.
And while neither ESA nor the EU get involved in international agreements like the Outer Space Treaty or Artemis Accords, the agency’s constituent members do. Of the 22 Member States, 10 have signed the Artemis Accords. All 22 Member States, four Associate Member States, and all but one cooperating partner have ratified the Outer Space Treaty.
Friendship in exploration
There are many benefits to engaging international partners in the exploration of space, such as pooling resources, leveraging expertise across national borders, and diffusing risk, which all enhance the overall capacity for scientific discovery and technological innovation. This collaboration allows for more ambitious missions, which would be significantly more challenging for a single country to undertake both financially and technically. Partnerships like that between ESA and NASA not only accelerate the pace of scientific advancement but also foster goodwill and mutual understanding among participating nations, laying the groundwork for peaceful cooperation in space exploration.
The opportunities that open up for collaboration do not occur on a regular schedule. Instead, each agency has its own processes for the selection, formulation, and implementation of missions. Normally, the decision of if and how to engage with international partners happens early in the lifecycle of a mission. Mission architects will consider multiple options at each decision point in developing their plan, weighing the scientific, technical, and logistical merits of potential collaborations against the backdrop of political, financial, and strategic considerations. This early integration ensures that the contributions from all parties are incorporated into the mission architecture. Such collaborations, though complex, are facilitated by a shared commitment to exploration and discovery, underpinned by detailed agreements that outline the roles, responsibilities, and expectations of each partner. This has the added benefit of developing political strength for missions to weather budget and schedule uncertainty, as well as geopolitical strains.
Past partnerships
ESA and NASA have a long-standing partnership on a variety of space missions, dating back to the earliest days of both agencies. ESA has been involved in many of NASA’s largest, most ambitious, and scientifically significant missions. This is in large part due to the past successes of the ESA-NASA partnership to deliver revolutionary science.
Cassini-Huygens: This mission was a collaboration between NASA and ESA, with additional support from the Italian Space Agency. The mission comprised two main elements: the Cassini orbiter, developed and managed by NASA, and the Huygens probe, provided by ESA. The collaboration was structured around a division of responsibilities that leveraged the strengths of each partner. ESA’s contribution, the Huygens probe, was designed to detach from the Cassini orbiter and descend onto the surface of Titan, Saturn’s largest moon. The Italian Space Agency supplied the high-gain antenna for the Cassini orbiter and other critical hardware components. This ambitious endeavor marked the first and, to date, only landing in the outer Solar System. ESA’s involvement was instrumental in maintaining the mission’s scientific objectives despite budgetary constraints and the restructuring of the project by NASA. The Huygens probe paved the way for future missions to Titan, namely the Dragonfly mission being developed by the Johns Hopkins University Applied Physics Lab.
James Webb Space Telescope: The partnership between ESA and NASA on the flagship observatory was inspired by the resounding success of the Hubble Space Telescope, prompting the agencies to come together in 1996 with the ambitious goal of developing Hubble’s scientific successor. ESA’s commitment was solidified in 2003, with its contributions becoming a cornerstone of the project by 2007. The Near-Infrared Spectrograph (NIRSpec), designed to ESA’s specifications and built by Airbus Defence and Space in Germany, incorporates detector and micro-shutter subsystems provided by NASA’s Goddard Space Flight Center (GSFC). Another instrument, the Mid-Infrared Instrument (MIRI), embodies the transatlantic partnership, developed jointly by European institutions and the Jet Propulsion Laboratory (JPL) in the U.S. ESA launched JWST atop the Ariane 5 rocket on Dec. 25, 2021, placing the spacecraft at Sun-Earth L2. The European Ariane 5 performed so well that the spacecraft has enough fuel left to support an extended lifespan beyond 10 years. The minimum benchmark is five years. This collaboration has ensured ESA’s full partnership in the JWST mission, granting European astronomers equal access to the telescope’s observations and guaranteeing them at least 15% of the observatory’s total observing time.