Spain has offered a package worth up to €1 billion to support the construction of the Thirty Meter Telescope (TMT) on La Palma in the Canary Islands. The Spanish site is currently the project’s designated alternative, with Mauna Kea in Hawaii remaining the preferred location.
Announced on 29 July, the package includes a €400 million contribution from Spain’s Ministry of Science, Innovation and Universities through the Centre for the Development of Industrial Technology and Innovation (CDTI), matching an initial offer made by the government in July 2025.
That proposed contribution will now be supplemented by a €300 million loan from the European Investment Bank (EIB), which remains subject to final assessments and approvals, and €300 million from Spain’s state-owned Instituto de Crédito Oficial (ICO). The language used for the ICO commitment, however, was far less firm, with the 29 July Spanish Space Agency press release stating that the bank was “considering a potential investment of up to an additional €300 million.”
The €1 billion proposal is still contingent, however, on the TMT consortium moving the project from Mauna Kea to La Palma.
Mauna Kea was selected as the primary site for the construction of TMT in 2009. In October 2016, La Palma was selected as the official alternate site. While that status remains unchanged, several factors are making it increasingly likely that the project’s consortium will shift its focus to Spain.
In October 2014, the groundbreaking ceremony for the facility was disrupted by protesters opposed to its construction on Mauna Kea, a site considered sacred by many Native Hawaiians. This was the first of many disruptions, including court proceedings and blockades. There are also concerns about the US government’s commitment to funding the project.
In its FY2026 budget request, the National Science Foundation (NSF) explained that TMT would not advance to the final design phase and would “not receive additional commitment of funds from NSF.” Instead, the agency proposed focusing on the Giant Magellan Telescope, which is under construction in Chile.
Congress did overrule that proposal, directing NSF to advance both telescopes to final design review. However, it did so while stipulating that this be done “at no cost to the Federal Government.”
In its FY2027 budget request, NSF once again stated its preference for GMT, stating that it had “selected one project, the Giant Magellan Telescope (GMT), to advance to the Major Facility Final Design Stage.” The request provides no design funding for GMT or any other Extremely Large Telescope project. TMT is not mentioned in the document.
The €1 billion financing package represents almost a year of work by the Spanish government, beginning with a formal offer in July 2025 to provide up to €400 million if TMT were built on La Palma. By November, the TMT consortium said the Spanish proposal represented a “promising avenue for a new observatory” and agreed to work with Spain’s Ministry of Science, Innovation and Universities to develop a detailed roadmap towards the potential realisation of TMT on La Palma.
