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Successful Rosetta Lift-Off
CrystalFalcon writes "The BBC is reporting that the Rosetta spacecraft has had a successful lift-off after a two cancelled launch attempts. Rosetta is targeted at a near-Earth comet, and features a 'lander.' The European Space Agency has more information on the mission."
Rosetta's heading out to drop the 'Philae' lander onto Churyumov-Gerasimenko. Curious name for a lander.
I wonder how the lander is going to stay on the comet once the comet gets closer to the sun and starts ejecting mass.
1: if the harpoon doesn't get a good hold, the probe probably will drift away from the comet. Getting the probe that close in the first place will still be a huge achievement, and it'll still return useful data.
2: It's a comet. An orbital ice-berg that's been bashed around for billions of years. A little harpoon isn't going to break it in half. Might smash a small chunk off, but it won't split the comet in half.
3: The lander's heading toward the comet already, the harpoon launch recoil (assuming there is any) is unlikely to overcome the probe's momentum. And it is probably a small rocket harpoon, with practicaly no recoil.
As for the drill-and-screw...a harpoon would be far more likely to get the initial hold. It's a quite well understood technology. On Earth, drilling typically requires rather firm support for the machinery doing the drilling. For the probe, it would require maneuvering up to the comet and holding position next to it while it attempted to drill in an anchor, at a distance from any human which makes real-time remote control impossible. Plus, it would be far more mechanically complex, a lot heavier, and a lot more power-hungry. The harpoon could use a small solid-fuel rocket, the drill would require a motor and power supply to run it. Not to mention the fuel required to hold the probe in place while drilling.