British scientists, royalty, and dignitaries gathered in London to wave goodbye, metaphorically at least, to the Beagle 2 spacecraft.
By Helen Briggs
BBC News Online
There were cheers, smiles and handshakes when the news came through that the probe had separated from Mars Express, and begun the descent to the Red Planet.
The Duke Of York (left) congratulates Colin Pillinger
While clearly relieved, lead scientist Professor Colin Pillinger, said he wouldn't be happy until Beagle 2 was safely on the surface carrying out science experiments.
"We've still the second leg of the semi-final to play," he said, referring to Beagle's plunge through the Martian atmosphere.
"Tick a box, move on, tick another box", he added, "we're not happy until we get to the surface."
Beagle supporters assembled at the Royal Geographical Society in Kensington to watch a screen transmitting live footage from the European Space Agency's control centre in Germany.
After separation was confirmed, the science minister, Lord Sainsbury, congratulated the Beagle team, saying the project represented the best in British science and engineering.
He wished them the best for the next step, the landing on Mars.
"Congratulations on today's manoeuvre, it's a great success and best of luck for the future," he said.
Everett Gibson, US space agency scientist, and a member of the scientific team that claimed in 1996 to have found fossilised bacteria in a Martian meteorite, was among the audience.
He told BBC News Online that Beagle could take the next, potentially giant step, in answering the question: is there life on Mars?
0710 GMT - Green light for separation granted
0831 GMT - Separation command given
1031 GMT - Contact was re-established
1110 GMT - Confirmation of launch
1400 GMT - Image of launch released
"Beagle has the nice suite of instruments that you could take to Mars and seek those signatures of life," he said.
He said the probe would be able to look for the signatures of carbonates and organic compounds not in meteorites but on Mars itself, where there is no risk of confusion with bacteria from Earth.
"Beagle is taking the experiment to Mars and doing it in a non-contaminating environment," he said. "That's wonderful. Good science."
Also in the audience was Professor Geoffrey Eglinton who worked on the Apollo lunar samples at Bristol University in 1969 with Colin Pillinger, then a young post-doc.
"In the sense that the spacecraft's on its own and ready to descend, it's a very historic moment," he said.
"But it's historic I think because for a start you saw Europe working together extremely well, which is something I would never have dreamt of in 1969."