Surely you mean 10cm?

My word. I and at least one other poster here were misled by the picture at the top of the article.

But, for whatever it's worth, a trip to Wikipedia tells me that they took 2 years off, due to covid.

It's more realistic to say that covid caused logistics issue two summers in a row. The first summer was presumably 2020 when almost every country locked down. In 2021 things weren't much better and the various polar programs were dealing with both caution and a backlog of issues from the previous year.

The actual downtime may have been significantly less than 24 months but still could have killed progress for 36. There's a pretty small window that you can deploy for these sorts of operations.