Editorial | ESA Makes History with Rosetta


The European Space Agency, and in particular the ESA member states that chose to participate in the Rosetta comet-chaser mission, received a large and well-deserved dose of satisfaction Aug. 6 when the spacecraft finally arrived within striking distance of its destination.

After a journey of more than 10 years following a combined investment of $1.75 billion, Rosetta is now within 100 kilometers of Comet 67P/Churyumov-Gerasimenko and has sent back stunning images that are already changing the way scientists think about these mysterious objects. It has been widely assumed that comets are giant, dirty slush balls, but based on initial assessments of Rosetta’s data Comet 67P appears to more rocky than icy.

Over the coming weeks and months Rosetta will continue to track the comet as it approaches the sun, in the process kicking out increased amounts of water vapor and dust. Rosetta is the first probe to rendezvous and fall in step with a comet — previous missions to comets have been flybys.

Gradually, the spacecraft will close to within a distance of 10 kilometers before deploying a lander that will anchor itself to the surface of the comet — another first.

The resulting scientific discoveries — indeed the imagery alone — promise to be breathtaking, assuming success, of course. Already, however, top space officials with the participating nations — notably Germany, France and Italy — are rightly touting Rosetta’s arrival as validation of their substantial investments in the mission. Germany’s space minister also praised ESA’s smart use of social media to engage young people as the mission progresses.

Notably, these same countries face tough negotiations later this year that will shape the future of ESA’s launcher program and participation in the international space station.

But for the moment, why not bask in Rosetta’s glow? Though tricky maneuvers lay ahead, Rosetta is already a showcase of ESA’s technical prowess — it’s worth noting that this mission was designed in the 1990s — and a reminder that investment in flagship-class science missions is money well spent.