"So what do we get for our €1.4bn? Rosetta is both an astounding feat of engineering (catapulting a tonne of spacecraft across millions of kilometres of space and ending up in orbit around a comet just 4 km across) and an extraordinary opportunity for science (allowing us to examine the surface of a lump of rock and ice which dates from when the Solar System formed).
Like a lot of blue-skies science, it’s very hard to put a value on the mission. First, there are the immediate spin-offs like engineering know-how; then, the knowledge accrued, which could inform our understanding of our cosmic origins, amongst other things; and finally, the inspirational value of this audacious feat in which we can all share, including the next generation of scientists.
Whilst those things are hard to price precisely, in common with other blue-skies scientific projects, Rosetta is cheap. At €1.4bn, developing, building, launching and learning from the mission will cost about the same as 4.2 Airbus A380s—pretty impressive when you consider that it’s an entirely bespoke robotic spacecraft, not a production airliner. On a more everyday scale, it’s cost European citizens somewhere around twenty Euro cents per person per year since the project began in 1996.
Rosetta has already sent us some stunning images of Comet 67P/Churyumov–Gerasimenko and today’s landing will, with any luck, provide us with our first close-up glimpse of the chaotic surface of this dirty snowball. If you’re a sci-fi fan, then, you might consider the mission to have been worth its price tag just for the pictures. The total cost for the Rosetta mission is about €3.50 per person in Europe; based on the average cinema ticket price in the UK (€8.50), it has cost less than half of what it will cost for you to go to see Interstellar.”