But, in your opinion, for the moment (if no special inconvenience), do you think the LSST has more probability to be launched in November or December?
I’m interested because it takes a certain amount of time to detect distant moving solar system objects (at least two or three weeks to link 5 or 6 images from different nights and each pointing is repeated only after 3-4 nights [or more if bad conditions]), and some areas will no longer be observable in the night sky already by late December or early January. And then we’ll have to wait until April or May for them to return. For example an area that is not observable from 5th of January anymore will be observable again only from 1st of May. So, if the LSST started only on 25th of December, we wouldn’t be able to find distant mobile objects of this area before may 2026.
For the area I’m interested in, the launch should be before the 15th of December. If not, I’ll have to wait until May…
Does someone can tell me if we can expect the LSST launch to be closer to 1st of December than to 31st of December ?
“Substantial completion is now planned to be presented at the joint Construction Closeout Review 3 (CCR3) / Operations Readiness Review 2 (ORR2) to be held 23 and 24 October.”
@bechtol : “The Operations team is ready to assume responsibility for the Observatory on 25 October 2025, and the goal is to begin the Legacy Survey of Space and Time (LSST) by the end of this year, though some challenges and tasks remain that must be addressed first.”
I suspect nobody is going to be able to answer your question, because we don’t really know yet.
However, I will make a less controversial point which is this:
even if we start in November or December, we will not have template images available in order to do difference imaging for quite a while (I wouldn’t feel like I was underestimating this if I said several months) – and we need to be able to do difference imaging in order to do most of the standard solar system object detection and thus announcing of new objects. So I think you’re likely to have to wait until May.
More generally though – we want to get things working correctly and as reliably as possible, as soon as possible. We will start as soon as we can start, and patience from the community while we are hard at work is appreciated.
(I’ll edit this to say — won’t have template images available over more than a very small amount of the sky at the start of the survey, and as @jrob93 showed below, it takes a while to ramp up to cover significant portions of the sky).
To second what Lynne said (and to shamelessly self-plug some work) I recently looked at how template generation would affect the discovery of solar system objects in year 1 and several months is a very likely delay for the alerts to start flowing (Radware Bot Manager Captcha). Here’s a figure showing the transneptunian object discoveries as a function of time, comparing the “baseline” which already has templates and simulations where templates are generated incrementally:
It’s also worth pointing out that although there will most likely be no templates and no real-time alerts of the field you are interested in when it is observed, any moving objects there should be detected when all the observations are reprocessed for Data Release 1 (I think this is nominally scheduled for late 2027/early 2028).
@ljones is correct. At this stage, the best estimate we can provide is that we expect to begin the LSST by the end of 2025. We will continue to refine this estimate and update the community as we make progress.
