A leading British scientist is about to relive the tension and excitement of Beagle 2 when Europe's Rosetta spacecraft begins a long journey across the solar system to meet a comet.
Ian Wright, deputy head of the Open University's Planetary and Space Sciences Research Institute, led the team that designed a key instrument on board the Martian probe lost on the red planet's surface last year.
Next week, he will travel to French Guiana to watch the launch of Rosetta , which will carry 21 instruments including Ptolemy, another of Dr Wright's devices, to Comet Churyumov-Gerasimenko.
After the disappointment of Beagle 2 's loss, the British scientist is philosophical about the prospect of a ten-year wait before learning whether another ground-breaking experiment can escape a similar fate.
"I don't need to overstate the risk in these missions - everybody involved understands that," Dr Wright said.
"From the start of this project to its finish is 20 years - half a scientific lifetime - and you might then find that a wire has come out and it doesn't work."
Rosetta had been primed to travel to Comet Wirtanen, but its launch last February was postponed amid technical concerns.
The mission will now investigate how Comet Churyumov-Gerasimenko's composition changes as it flies towards the sun.
Part of the spacecraft will accompany the comet along its trajectory for several months while the lander Philae will use harpoons to grip the surface of its nucleus, which could have a consistency ranging from concrete to candyfloss.
Ptolemy will sit at the heart of the lander. It will analyse gases extracted from samples of comet material in a similar fashion to Beagle 2's spectrometer.
From the relative quantities of different isotopes, Dr Wright will look at how water from the comet differs from water on earth, giving scientists a glimpse into the chemistry of the early solar system.