Em que ano recebemos o sinal da Vega?

No romance não está especialmente claro, mas a máquina parece ter levado cerca de uma década (e possivelmente entre 5-15 anos) para construir o que significa que o sinal foi (provavelmente) recebido por volta de 1989-90.

IT TOOK years, it was a technological dream and a diplomatic nightmare, but finally they got around to building the Machine. Various neologisms were proposed, and project names evocative of ancient myths.

e

Eventually, it came to half a trillion dollars a year for some years, roughly a third of the total military budget--nuclear and conventional--of the planet.

e quando a máquina se aproxima da conclusão;

The daily headlines in The New York Times were, by any dispassionate measure, more bizarre than any in the now defunct National Enquirer a decade earlier.

O script indica que o sinal foi recebido em 1996 ou no início de 1997.

Ellie parece se juntar ao SETI no Novo México em 1993

EXT. NEW MEXICO DESERT - AERIAL SHOT - NIGHT

A 1967 T-Bird travels swiftly along a dirt road through the moonlit desert. The VIEW CLIMBS, WIDENS to include a huge radio telescope, and as we come around we see an even more stunning sight: 30 more of them.

SUPERIMPOSE: SAPPORO, NEW MEXICO - 1993

Quando Drumlin visita, é um ano eleitoral (então presumivelmente 1996)

      DRUMLIN
  Very well; since my appointment he's
  been made interim director.

              ELLIE
  Really?  Congratulations, by the
  way.

              DRUMLIN
  I'm surprised you even knew it was
  an election year.

... e o sinal é recebido logo em seguida.