TMT mega-project on La Palma rejected despite billions-euro bid

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The partners in the Thirty Meter Telescope project have rejected Spain's offer of billions to build the telescope on La Palma.
The offer amounted to up to one billion euros, of which 400 million came from the CDTI and 600 million as a loan from the EIB and ICO.
The IAC wishes to retain Roque de los Muchachos as an astronomical site and attract other research facilities to La Palma.

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It was set to become the flagship scientific project in the Canary Islands. However, the partners of the «Thirty Meter Telescope» (TMT) have rejected Spain’s billion-euro offer for La Palma. The executive director of the operating company, TMT International Observatory (TIO), sent a rejection letter to the Institute of Astrophysics of the Canary Islands (IAC) and the Ministry of Science on Friday. The letter stated that the members had failed to reach the necessary consensus. The IAC published the rejection in a press release on Monday.

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The Ministry put forward the proposal on 29 July. It provided for funding of up to one billion euros for the construction of the giant telescope at the Roque de los Muchachos Observatory (ORM). 400 million euros were to come from the Centre for Technological Development and Innovation (CDTI). The aim was to take an equity stake in the project. A further 600 million euros was to be covered by a loan involving the European Investment Bank (EIB) and the state-owned development bank ICO.

However, a review by the organisation’s members failed to produce the necessary consensus. Consequently, the TIO will not be taking the necessary steps to commence construction at Roque de los Muchachos in the near future. This means that around ten years of joint work have, for the time being, produced no result. The IAC is, however, planning further, similar projects on the mountain on La Palma.

The history of the TMT billion-euro funding package

The billion-euro funding package was put together in several stages. In 2025, Spain, under the leadership of the Ministry of Science, submitted an initial offer. This provided for 400 million euros via the CDTI for the construction of the telescope on La Palma. The remaining 600 million euros were secured through discussions between the Ministry, the CDTI and the European Investment Bank.

In close consultation with TIO staff and the European institutions, the Ministry submitted the comprehensive proposal in July this year. The project’s funding requirements were thus fully met. Nevertheless, the proposal has now been rejected.

Space science: support on La Palma and in the Canary Islands

The institutions of the Canary Islands demonstrated strong solidarity and a clear consensus in favour of La Palma within the framework of the project. The Island Council, the Government of the Canary Islands and the University of La Laguna were quickly identified as preferred partners. The IAC expressed its gratitude to the people of La Palma and the Canary Islands in general. It was stated that the willingness to host this and other research projects makes the Canary Islands a globally unique location for astronomy.

According to the IAC, Roque de los Muchachos is set to remain an attractive location despite the recent cancellation. The mountain is one of the best astronomical sites in the world, it was further stated. The Institute will therefore continue to support the scientific and technical development of the observatory and seek to attract other internationally significant research facilities to La Palma. These would include, for example, the medium-sized telescopes of the Cherenkov Telescope Array Observatory (CTAO) and the European Solar Telescope (EST). The IAC aims to secure Spain a leading position in the future of astronomy.