An extract from a newspaper "The Star, Thursday 5 June 2008'

Nasa: Toilet trouble won't force ISS evacuation


"At this point in time, we dont't believe that the ISS would be forced into a de-crewing situation," ISS deputy programme manager Kirk Shireman said at Nasa's Johnson Space Centre.

The ISS can use the shuttle's toilet while it is moored at the station, while special bags to collect urine were also available, he said.

Disposing solid waste has not been a problem, he added.

"It's unfortunate we're talking about toilets, but that really is the life, the future of human exploration in space," Shireman said. ...-AFP


What is the synonym and meaning of the underlined word 'it' in bold of the last paragraph?

Thank you.

With best wishes.
In this context and position "it" is used to emphasize a following part of a sentence.
bhikkhu1991What is the synonym and meaning of the underlined word 'it' in bold of the last paragraph?
bhikkhu1991It's unfortunate we're talking about toilets
The word it in that sentence has absolutely no meaning. It is a place holder in a grammatical structure.
The underlying sentence is this:
The fact that we're talking about toilets is unfortunate.
Or, simply: That we're talking about toilets is unfortunate.
Sentences that begin with a that clause can be transformed by substituting it and moving the substituted clause to the end of the sentence:
It is unfortunate that we're talking about toilets.
The word it holds the place where the that clause was located before it moved to the end.
That we arrive on time is important. = It is important that we arrive on time.
That Paul will be late is certain. = It is certain that Paul will be late.
That Catherine bought so many shoes is surprising. = It is surprising that Catherine bought so many shoes.
It is more common to use the structure that starts with it than the equivalent one that starts with that; the meaning is the same.