Following on from last week’s update, the team on Cerro Pachón spent this week moving from bringing systems back to life toward actually exercising them. We are still off sky; here is where things stand as of October 2.
Power
The site continues to run reliably on generator power, with the electrical crew on site around the clock. Routine maintenance on the backup generators went ahead as scheduled. All the spare parts needed to repair the site’s primary generator have now arrived, and preparation for that repair — connection checks and insulation measurements — is planned for the weekend without affecting other work. At the Auxiliary Telescope, the building and main equipment cabinets were re-energized, and all cabinet equipment tested healthy.
Cooling and camera systems
The Dynalene coolant system that serves LSSTCam is now recirculating through a bypass loop, ready to be connected to the camera once refrigeration work is finished. On the camera itself, the team continued with repairs and maintenance on the refrigeration systems and on-board computers. Brief power-on checks will ensure systems are ready for the final pumping and cooldown, scheduled for next week.
Telescope and optics
The cold glycol loop is now being filtered thoroughly before it is reconnected to the primary/tertiary mirror cell using a recently upgraded system. The secondary mirror was placed under closed-loop control for the first time since the storm, and the rotator was exercised multiple times to support Camera work and responded as expected. The primary mirror is receiving an in-situ wash using newly tested equipment and a personnel basket for the dome crane; early test areas showed a dramatic improvement.
Dome and mechanical work
The first (of six) Light/wind screen panel completed its first full manual slide-out along its 15 m of travel. It ran smoothly in its tracks, with light and even chain tension, which sets things up well for motor testing. The air compressors are back under remote control. Dome shutter, rotation and louver tests move to next week once the mirror wash wraps up.
Communications and computing
All summit computing clusters have been restored to full operations, and the observatory control system is online. The scheduler is enabled, with the observatory formally still in downtime, and telemetry and the engineering database are running to support camera start-up.
What’s next
Planning for the return to night operations has started, and anticipate to resume the LSST as soon as possible after a brief shakedown of the hardware and software. We don’t have a specific return-to-sky date to announce yet; as we said last week, we expect to be back on sky in the next few weeks, and we’ll keep posting updates here.
Thanks to the summit and teams across the project — camera, optics, mechanical, electrical, facilities, IT, DM and night operations — for another productive week.