How to know if a Planned Sentinel-2 Acquistion is definitively absent?

I am building a google calendar system to inform users in Sardinia, in a timely nature, of the dates for which Sentinel-2 data has been acquired. Try it out here:
(there’s also a webext to insert the quicklooks into the event descriptions)
I do this by querying the data-hubs. Generally, Sentinel-2 products arrive in the data hubs within a week or so of Sensing Time.

During that week a planned acquisition remains in limbo, either:

  1. all goes well and the products eventually arrive or
  2. there is some rare event and the absence hangs on.

That acquisition are planned can be derived from the acquisition plans posted a fortnight or so in advance (in machine readable XML) here:
Planned absences can be inferred where ever an item (Placemark) does not indicate NOBS mode. This takes some work to do this but I now have working code.

However, the ongoing absence of data from
Sentinel-2B Relative Orbit 065 for 10:20 UTC on 22 May 2019
doesn’t seem to have been announced in any acquisition plan,e.g. here:

An alternative indication of this absence is given on the ESA News site:
– in a less machine-interrogable form. The relevant article is:
But that indicates the downtime was planned be over an hour or so before the aforementioned missing products.

Since things can understandably go awry after plans and news get published
I ask is there a definitive expiry period after which one can be pretty sure that
the absence of a product is permanent?
Or perhaps there is another source of information which I am missing?

1 Like