There was to be no equivalent to "the Eagle has landed". No champagne corks were popped, no balloons released, there was not even a solitary whoop.
Instead, when it was confirmed that the Huygens probe had safely touched down on Titan, the assembled audience preferred to fill the hallowed halls of the Royal Society with applause. This technological triumph was, after all, in part a very British coup.
But there was no mistaking the excitement among the 70-odd scientists who gathered in central London on Friday afternoon as events unfolded 1.2 billion km away. After their last Christmas was wrecked by a futile hunt for a lost dog ( Beagle 2 ), they were due a result. And they got one.
On the podium before us, Colin Pillinger, professor of planetary sciences at the Open University, attempted to inject a note of caution. "Keep your fingers crossed - we haven't got any data yet and this is a high-stakes game," the chairman announced.
But Professor Pillinger's broad smile betrayed his high hopes, a quality that made him such an inspirational and, ultimately, tragic figure when Beagle 2 went missing on Mars.
His willingness to confront the media again just a year after being unfairly lampooned for that previous failure, suggested a man cut from the same cloth as former England defender Stuart Pearce, who famously took (and scored) a crucial penalty for his country six years after infamously missing one against Germany.
This time the Germans were on our side - Huygens was a truly international affair - and images of nervous scientists in the European Space Agency's Darmstadt control room were projected on to a big screen behind the podium.
Despite Professor Pillinger's high profile, the star of the show was John Zarnecki, professor of space science at the OU and principal investigator on Huygens' surface-science package. His grin popped up periodically on screen as the news got better and better.
"The carrier signal has been picked up and 15 years of pent-up emotion have just been released in the control room," he told us, prompting a fresh round of whoop-less applause.
Two rows of OU postdoctorate students beamed. Among them, Rebecca Wilson enthused about how inspiring the day had been and the scale of the achievement for UK science and technology.
Sitting quietly, Paul Birchley, a physics teacher who had worked on Huygens since its inception, smiled when recalling the excitement among his pupils at the imminent landing: "It has captured their imagination."
The industrial engineers whose parachutes, software and hardware had helped ensure the success were likewise elated. As were Professor Zarnecki's proud parents.
As the afternoon progressed, David Southwood, who last year broke hearts at the Beagle 2 landing press conference with the words "I'm afraid I have to make a sad announcement", started talking about posterity and joking about British mineral rights.
Professor Zarnecki confessed to having won "a rather nice bottle of Scottish medicine" in a team sweepstake to guess the landing time.
As things got giddy, there followed some emotional thank yous.
Professor Zarnecki kept it short - he didn't want to forget anyone.
Nevertheless, Professor Pillinger noticed a painful omission.
"You forgot the guy on the grants panel who awarded you the grant," he observed.
"Oh yes," Professor Zarnecki nodded on the big screen. "Thanks Colin."