Untitled - ESO

The activities within the EU FP6-supported
ELT Design Studies programme,
led by ESO but largely executed in
industry and academia outside the
organisation, are aligned with the
activities of the E-ELT programme and in
all areas much progress is being made.
Actuator prototypes, edge sensors, phasing
techniques, wind evaluation systems,
dome designs, site testing and many
other such activities are all contributing to
the knowledge we require to advance the
project into the next phase. Integral to
this planning is the membership of Spain
in ESO and the expertise that the Spanish
community will bring. Spain has just
completed the segmented 10.4-m Gran
Telescopio Canarias (GTC) telescope
and, with Spain’s membership, ESO
engineers will gain technical access to
that system.
Participants to the E-ELT conference in Marseille.
46
ESO Annual Report 006
The baseline reference design selected
and approved by the ESO Council to
move into the Phase B of the project is
the five-mirror design. While the Gregorian
design had advantages in a better
theoretical performance in adaptive optics,
a smaller mirror count and smaller
central obstruction, the five-mirror design
was considered to have advantages in
the image quality across the focal plane,
the control of the wavefront using laser
guide stars, the flexibility of the focal stations,
the deployment of atmospheric
dispersion compensators, the smaller
dome and the relative ease with which it
could be upgraded to follow the development
of technology in the future. Most
critically however, the five-mirror design
was considered to have much lower risk
in the area of adaptive optics by virtue
of the separation of the field-stabilisation
and adaptive-optics functions, a key recommendation
of the OWL review.
Into Phase B
The results of this burst of activity came
together during November 006 in preparation
for a series of presentations of
the Project Office conclusions to ESE,
ESRC, STC, to 50 astronomers at the
Marseilles meeting on the E-ELT and, finally,
to the ESO Council. The endorsement
of the Project Office proposal by
this broad spectrum of the community
and decision makers reflects not only the
good progress ESO made during 006
in the elaboration of the design but also
the clear scientific need to advance
rapidly and effectively in the area of E-
ELTs and the commitment of the user
community.