I am not familiar with the Titanic and Space Shuttle analogies. I would be interested in hearing more about them.
However there have been 6 understandings of what the 'Generation' is in Watchtower history.
1) From C.T. Russell's time.
A generation of contemporaries, "people living contemporaneously ... In other words the signs mentioned will occur within a generation - epoch in the close of an age" (Studies in the Scriptures, Vol 4, p. 602, 603)
2) From Judge Rutherford's time.
The anointed. "The irresistible conclusion therefore is that Jesus referred to the new creation [the anointed] when he said: "This generation will not pass away..." ...some members of the new creation will be on earth at the time of Armageddon" (W 2-15-1927, p. 62)
3) From the early 1950s.
The 1914 generation. Those born before (later changed to during) 1914. "Some persons living A.D. 1914 when the series of events began will also be living when the series ends with Armageddon. All the events will come within the span of a generation." (W 9-1-1952, p. 543)
This view was held the longest, for several decades from about the early 1950s until 1995.
4) From 1995.
The general population of earth's wicked people. "Therefore in the final fulfillment of Jesus' prophecy today, "this generation" apparently refers to the peoples of the earth who see the sign of Christ's presence but fail to mend their ways." (W 11-1-1995, p. 19)
This was the least comprehensible one to me. I never really saw how it made much sense. It seems to be similar to the first view, a general generation of people living contemporaneously when the end comes, but witht the emphasis on them being wicked.
5) From 2008.
The anointed. "As a class, these anointed ones make up the modern-day "generation" of contemporaries that will ot pass away "until all these things occur."" (W 2-15-08, p. 24)
This one seems to be another throw-back, to the second view, a re-adoption of previously abandoned 'old light'.
6) From 2010.
The overlapping generation theory. "He [Jesus] evidently meant that the lives of the anointed who were on hand when the sign began to become evident in 1914 would overlap the lives of other anointed ones who would see the start of the great tribulation." (W 4-15-2010)
I suppose with this view, the Watchtower could keep 'overlapping' the generations as far into the future as they needed to, and still call it 'the generation' that Jesus referred to.