By Jonathan Amos
Science reporter, BBC News, Kennedy Space Center
And so, finally, Columbus has begun its voyage.
Tucked away inside Atlantis' cargo bay, the European science lab thundered off the Kennedy pad and raced skywards for a rendezvous and docking with the International Space Station on Saturday.
The gathered VIPs and Nasa workers roared their approval. The parked cars hooted as the vibration from the ascending orbiter set off their alarms.
The moment has been a long time coming. Even in its current guise, Columbus should have been on-station six years ago.
There was time-slip because the Russians had financial concerns in the early days of the ISS project, and then there was the enforced delay resulting from the 2003 shuttle disaster.
But for those with longer memories, Columbus had an even earlier guise, as part of the ill-fated Freedom Space Station project that was considered (but never built) to counter what the Soviets were doing in orbit with Mir.
So Columbus has already had a long journey; and now, within a week or so, the first science experiments should at last be up and running inside the module.
The microgravity work is expected to have benefits across a huge range of products and processes on Earth - helping researchers develop new materials, drugs, and crops.
For Europe, it is a key time in its exploration of space - and in the development of ambition.
For the first time, Europe will be running human spaceflight operations itself, commanding Columbus and the astronauts inside from a control centre in Oberpfaffenhofen in Germany.
The module's installation will mean Europe becomes a full member of the ISS project; and this will trigger a series "rights and obligations".
Among the rights are crew spaces - one six-month residency on the platform every two years. Among the obligations is Europe's commitment to keep the station functioning through the provision of logistics; and this requires Europe to fly a new cargo ship to the station about once every 18 months.
The first 20-tonne Automated Transfer Vehicle, as it is known, is itself now just weeks away from launch.
And in many ways, despite all the hullabaloo over Columbus, this new vehicle may actually turn out be the more important of Europe's two big contributions to the ISS.
Yes, Columbus remains the focus for now; it should be flying overhead for at least 10 more years. But for many in this game, the future of human space activities lies beyond low-Earth orbit - going to the Moon and perhaps Mars.
And the ATV brings new enabling technologies - automatic rendezvous and docking - that should play a part in this expanded future.
ATV - SPACE CARGO TRUCK
ATV will resupply the ISS with up to 7,500kg of cargo
Deliveries will include science equipment, food and clothing
Large tanks can transport vital air, water and fuel supplies
ATV project's estimated cost is about 1.3bn euros (£0.9bn)
At least four craft will follow the maiden ATV - Jules Verne
Named after the author who wrote about fantastic journeys
At the moment, Europe has to rely on the Americans and the Russians for everything it wants to do in space with humans. No Esa astronaut can get into orbit without the shuttle or the Russian Soyuz.
And so this November, the director general of the European Space Agency, Jean Jacques Dordain, will ask ministers to give him money to investigate further technologies that could be incorporated into an independent, European crew transportation system.
In the first instance, this is likely to be re-entry technologies - how to bring humans safely back to Earth once they have been in space.
"The question is: will Europe embark on the development of a human transportation system or not?" he pondered as he spoke to European journalists after the successful launch of Columbus.
"On my part, Europe cannot be dependent forever; I don't see how Europe can chose today to say 'we shall be dependent forever'.
"And if Europe says what I say, let's start to build up the technologies which are necessary not to be dependent in the future."
Just when you have reached the brow of the hill, you realise just how much further you still have to go.