Dear Colleagues,
Nothing gives me more pleasure these days than to see your excitement when you engage with Rubin. At First Look, using DP1, visiting the summit, or talking with you at the Community Workshop. I think about you every day, and the thought of getting you data from the LSST, so you can do science motivates me constantly.
I know you all are excited to see the LSST begin. I know there is more than a little angst that we have not started, or even set the date to start. I know many of you need that information to plan for proposals and other aspects of your career development. Especially those of you in the early part of your career.
When we started the operations phase of Rubin in late October last year, I thought we would be in the LSST phase by now. That has not happened. While we have demonstrated Rubin works and is capable of meeting your science goals (and its requirements), we have not seen reliable performance image after image sufficient to call the start. We continue in a phase I call Early Operations Optimization.
Since October we have made progress on multiple fronts. The intra night fault rate is down and we are on sky most of the night now. The system contribution to delivered image quality (DIQ) has improved. We have experienced serious faults in the facility services and related camera cryostat issues. We had vulnerabilities to condensation on moist nights. All of these took us down for more than a month in total in Early Operations. We have mitigated all of these faults so they should not happen again.
We are working very hard to get the system to move fast across the sky and produce great images. Right now today, we are working on the control loop for the active optics system (AOS). We are also working on aspects of the wave front sensing itself which is used to inform the control loop. We continue to work on facility services to ensure maximum uptime and we are deploying various elements to the system to improve the thermal environment. Finally, notably, we started producing alerts when observing in LSST like mode.
I know you want to know when we will start. Today I don’t know, but I am working with the Rubin team on the path to the start of LSST. We have just completed nearly a month of intense engineering tests on sky. The team has worked incredibly hard to take these data. The tests in our plan that will help to address the reliability issues we face are nearly complete. We expect a few more weeks to finish this round. Going forward, the tests will be based on what we learn from the current tests and be less frequent and the analysis will take longer. Thus, we will soon begin a phase of more LSST-like observing and less engineering. This is not the beginning of the LSST necessarily. That decision will be performance based. I will check in with you later this month to let you know how we are doing and what to expect for the survey start.