Way back in November of 2014 the Little Lander That Could captured our hearts. The lander in question was Philae and the comet it landed on was 67P, or Churyumov–Gerasimenko to its friends. Orbiting above was the Rosetta spacecraft acting as relayer of messages and photographer for this historic mission.
Who could forget the dramatic landing Philae had to endure? The landing systems didn’t work properly and so the probe bounced having touched down. Gravity is so slight on the comet, however, that it bounced a kilometre back into space even though it was only travelling at about 0.35m/s. It took nearly two hours for it to come back down to the surface where it bounced for a second time before finally coming to rest slightly wonkily in the shadow of a nearby cliff.
It’s precarious position meant that it wasn’t able to generate as much solar power as had been planned and so the unit was never able to carry out all the tasks that had been planned for it. Nor has it been able to send back all the data it did manage to get. Over the intervening 14 months or so various attempts to contact the lander have been made. There was brief success last summer when Philae was able to generate more power as 67P journeyed closer to the sun but it was only brief.
The reason I write this now is that one last effort was recently made to resurrect Philae with the aim of getting a little more of that precious data back to earth. Sadly, mission control at the German Aerospace Centre in Cologne announced that the attempt had been unsuccessful and that all hope had essentially been lost.
Whilst this is sad, the mission as a whole has achieved so much that all those involved can feel very proud of themselves indeed. This was the first time we had ever put something in orbit around a comet. That, in itself, is remarkable given that the comet is only a couple of miles long and is moving at 84,000 mph. Also, the images sent back by Rosetta as the comet reached perihelion have given new insights into how these mercurial visitors to the inner solar system behave once the sun’s energy begins to warm them up.
Whilst not the unparalleled success that the New Horizons mission to Pluto was it is, nonetheless, a mission full of discoveries. For me, the most interesting discovery was that the isotopic composition of water on the comet was markedly different from water here on earth. This would suggest that the water we have on earth was not deposited here by comets as some people had theorised.
The Rosetta/Philae mission, then, has been a great success. It is now entering it’s final stage where the Rosetta orbiter will get ever closer to the surface before finally landing itself this coming September. It is hoped that it may get close enough to give us one last look at the Little Lander That Could.