I spent a couple of days this week in at MPIA in Heidelberg, working with my colleagues from MPIA and CEA Saclay in Paris on commissioning and calibrations plans for the James Webb Space Telescope instrument MIRI. The launch of JWST in 2018 is coming ever closer, and excitement is slowly building for this amazing project going live.
On the way back to Oxford I bumped into one of our local members of the ESO Council, who was returning from the meeting in which another major observatory project, the European Extremely Large Telescope, was given the go-ahead. This is news the whole community, and particularly those working in optical/IR instrumentation like myself, had been eagerly awaiting for a long time; we are very pleased indeed.
ESO have had a tough situation on their hands with the E-ELT in the last few years. The accession of Brazil to the organisation had turned from a sure thing a few years ago to an awkward silence. As Brazil’s membership would come with a sizeable cash injection to kickstart the E-ELT construction, the project stalled along with Brazil’s parliamentary ratification of the accession.
Of course lots of work was being done at ESO, and by the whole European community (including in Oxford, which is leading one of the first-light instruments, the spectrograph HARMONI). But it’s a bit awkward spending lots of national cash without formal clarity on the overall top-level funding situation. As long as ESO didn’t have at least 90% of the budget secured, they couldn’t move forward with the complicated business of actually building the telescope.
So what’s now changed? First, ESO’s newest member state Poland have brought in some extra cash into the coffers. Second, and most importantly for us technical folk, ESO have created a phased approach for the construction of the observatory. The first phase is slightly de-scoped from the original plan, costed such that the money currently available constitutes 90% of the required budget. A few features of the telescope are being pushed a bit further into the future, so that we can now get on with the major building works. Equally, the teams building the E-ELT’s first suite of instruments now have clarity on the situation and can continue with the design with more focus than was possible before – that’s a good thing.
We’d known that this solution was in the works for some months, and now that ESO Council has given its approval, it’s been formally brought into force. De-scoping a telescope is never fun of course. The telescope will be missing some of its mirror segments in Phase 1, giving a slightly smaller light collecting area for the first few years. More importantly, the laser tomographic adaptive optics (LTAO) system, which allows the instruments to use adaptive optics technology over the whole sky, even when no natural guide star is available, will be shifted into the second phase. That will definitely impact the instruments’ performance somewhat in the first years of operation. The community is obviously mulling over these issues, and what they mean, but ultimately it’s a pragmatic solution that allows the project and the many people involved to move forward.
Once the remainder of the funds becomes available, from Brazil or elsewhere, ESO can formally plan for the second phase. Interestingly, the difference between the “full” E-ELT design and the phase 1 plans don’t diverge for a few more years. If the additional money materialises in the next few years, the phasing may not even be necessary.
International mega-projects for science are always a challenge to fund – that’s why we have so few of them. Building the E-ELT on the ground still costs a factor of many less than putting a telescope like JWST into space. I think overall we’re all quite pleased with ESO’s pragmatism in finding this solution, and it will be great to see the E-ELT’s construction in Chile begin.