4MOST passes Operations Readiness Review 3

by Harry Addison on 2026-10-12

4MOST successfully held its third Operations Readiness Review (ORR3) with ESO on 30 September 2026, marking another important milestone on the path towards the start of the survey. The review covered the current instrument operations status, as well as the latest delta Operations Rehearsal 4 (dOpR4) and Survey Programme Validation (SPV) reports.

The review concluded that the instrument and telescope are ready for operations. A few minor recent hardware issues, such as false vacuum alarms, have been resolved. Meanwhile, the thermal stabilisation of the telescope is being monitored to minimise the impact of dome seeing. The discussions also addreessed the status of the consortium-led operations in Europe, finding in particular that the feedback loop for target progress is now fully verified.

ESO expressed its appreciation for the substantial work carried out by the 4MOST team over recent months. With a successful last ORR we now look forward to start of survey operations in the coming month.