Emeritus Professor at the Open University, Zarnecki is probably the only scientist in the world to have worked on three spacecraft now resting on a comet, Mars, and a moon of Saturn.

Like other lonely landers – our avatars at the frontiers of knowledge – these probes took years to develop and build, survived perilous journeys around the solar system and some only lasted a matter of minutes before shutting down.

It is hard not to feel affection and, maybe even, a sense of guilt that we abandoned them.

“You spend years of your life living with these things – you eat, sleep and breathe them,” says Zarnecki. “You do become emotionally attached.”

Here is what happened to some of them:

Huygens

On 14 January 2005, the European Space Agency’s (Esa) biscuit-tin–shaped, 2.7m-diameter Huygens probe began its descent through the hydrocarbon smog that envelops Saturn’s moon, Titan. Suspended from the strings of a parachute – a landing system that had somehow survived a seven-year 3.5 billion kilometre (2.2 billion mile) journey – the European spacecraft captured the first-ever views of the alien world.

Two and a half hours later, Huygens was on the surface – relaying data back via its Cassini mothership, in orbit around Saturn. And 72 minutes after that, the lander was dead – its contact with Earth lost and its battery depleted.