As the biggest optical telescope of the next generation, ESO’s Extremely Large Telescope (ELT) will push the boundaries of our knowledge and capabilities. Making this wonder of modern science and engineering a reality has only been made possible thanks to collaboration between different people in an enormous variety of roles.

From scientists and engineers to project managers and technicians, a number of people at ESO work on the ELT. Indeed, the success of the ELT relies on the collective effort of all ESO staff, both in Germany and in Chile.

Among all the ESO staff members involved in the ELT Programme, this organogram shows the key responsibilities of some of the team members.

In addition to staff at ESO, countless contractors work for the ELT in companies across ESO member and host states. Also crucial is the huge contribution from many research institutes and universities working in consortia to build the instruments for the ELT. Without their efforts, the project would not be possible.

The ELT Project Science Team (PST) is an advisory working group that supports the ELT programme during the construction phase. It was established in May 2012 to provide input and advice to ESO and the ELT Programme Scientist. Specifically, the PST helps to: 

• refine, as necessary, the ELT science goals; 
• refine, as necessary, the observatory top level requirements, including the science requirements, performance metrics, and objectives for the telescope, the instrumentation, the operations and other scientific aspects of the project; 
• develop the instrumentation plan for the ELT and set the scientific priorities for the instrument procurement; 
• develop a science perspective on any major cost/schedule/science trades brought forward by the project. 
• In addition, the PST is expected to: 
• participate in the ELT reviews to coordinate scientific requirements and assist the ELT project in decisions as they relate to scientific objectives and scientific performance of the programme; 
• participate in the refinement of the project science plans and the philosophy for defining and conducting the science programme; 
• disseminate actively the information and explain the goals of the ELT to the ESO community. 
• The PST terms of reference are available for download. 

PST members 

In January 2012 ESO invited the astronomical community to nominate candidates for the ELT Project Science Team by the end of March 2012, receiving more than 80 strong nominations. The project was very grateful for the overwhelming response and the great interest of the community in helping to steer the project. 

PST members are appointed for a renewable term of 3 years. The current team composition is: 

Subsequently, the PST was joined by the following Principal Investigators of approved ELT instrument projects: 

In the future the PST will be joined by the Principal Investigators of further approved ELT instrument projects. 

Former PST members include: Jordi Cepa (La Laguna and IAC, Tenerife), Thérèse Encrenaz (Paris Observatory), Roland Gredel (MPIA Heidelberg), Rubina Kotak (Belfast), Ewa Lokas (Warsaw), and Didier Queloz (Cambridge). 

The predecessor of the PST was the Science Working Group (SWG), originally formed by ESO in December 2005 as one of five mixed community-ESO working groups (the other four being concerned with Instrumentation Design, Telescope Design, Adaptive Optics Systems and Site Evaluation). The work of these groups was required as crucial input to the Baseline Reference Design. Specifically, they were charged 

• to synthesise and collate ELT capabilities in the specified topic area, noting existing community studies and ongoing efforts 
• to propose a basis for prioritising capabilities in the specified topic area, a list of key trade-offs and an initial prioritisation of ELT capabilities; 
• to categorise science aims according to the related capabilities of an ELT and its instruments: field, pixel size, spectral resolution, multiplex capabilities and complementarity with other facilities. 

As a result of this work in April 2006 the SWG produced its first report. 

Later, in May 2006, the SWG merged with the OPTICON networking activity to further develop the science case for, and to provide scientific input to, the project. The group remained in place as a sub-committee of the ESO ELT Science and Engineering Working Group, which was itself a sub-committee of the ESO Scientific Technical Committee (STC). The new charge to the SWG was 

• to monitor and advise the ESO-ELT programme, and to advise the ESO ELT Science and Engineering group and the ESO Director General on all scientific aspects of the development of; 
• to develop the science case and justification for the ELT; 
• to stimulate discussions and interactions with the ESO community at large concerning the and its scientific performance. 

The list below shows the composition of the SWG at the time it was disbanded in February 2012. 

Previous members: Arne Ardeberg, Willy Benz, Robert Fosbury, Marijn Franx, Vanessa Hill, Bruno Leibundgut, Markus Kissler-Patig, Didier Queloz, Peter Shaver, Stephane Udry.