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 Image above is compliments of miglieruolo.wordpress.com  Image above is compliments of NASA. It is an artist's conception of the Philae Lander on Comet  Image above is compliments of IFLScience. It shows comet 67P/Churyumov-Gerasimenko and potential landing sites.
Although the main mission of the Rosetta Project is to investigate the history of our solar system and possibly, the origins of life in the universe and on our planet, there is another application of this mission. The most recent historic landing of a robotic space probe on a comet by the European Space Agency was an encouraging 1st step toward defending the Earth against interplanetary objects. This was a phenomenal achievement considering the distances involved as well as the speeds and precise control required to hit such a relatively small object hurtling through space. It was an in-genius use of "sling-shot gravity" to get enough speed and the right trajectory to catch up to the comet that was travelling about 84,000 miles per hour. Our current rocket technology cannot achieve the speeds required catch up to asteroids and comets, so scientists needed to use the gravity of planets to assist in gradually propelling the probe to greater and greater speeds. The landing was also nothing short of miracle engineering and communication with a robot so far away. However, the fact that this mission took 10 years to accomplish illustrates how far the human race still has to go to provide an adequate Earth defence against a future potential asteroid or comet strike. If a comet or asteroid ever threatens the Earth, one of the more likely defense scenarios would involve sending an "Impactor" to collide with the object in an attempt to "nudge" the asteroid or comet out of its flight path, thereby missing the Earth. The biggest challenges in this defence scenario are: 1) building an impactor with an enormous mass, large enough to make a difference. The mass of the impactor will have to be huge, and likely would have to be built in orbit piece by piece, just like the space station, due to weight-fuel restrictions of escaping Earth's gravity. 2) After construction is complete, the impactor would have to be propelled to speeds similar to the Rosetta devise (i.e. 84,000 mph). The only way to do this with today's technology is to use gravity of nearby planets and angular momentum (just like Rosetta) to gradually increase its speed and then hit the object at the right moment to change its trajectory. Everything in space seems to be travelling at about 50-100,000 miles per hour, so this is an enormous challenge. 3) The third important challenge is hitting the object at precisely the right time to change its flight path. When we are talking about controlling a robotic devise 100's of thousands of kilometers away, this is a huge challenge. Also, hitting it too soon or too late may be insufficient to cause enough change in trajectory. Congratulations to the European Space Agency, who just demonstrated that 1 out of these 3 tasks is possible! Maddalena Environmental Inc. Al Maddalena |
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