Wednesday, December 03, 2014

Far Away in Time and Space

It takes a little planning: design a spacecraft and attached lander which will travel 4 billion miles in space to a comet 2.5 miles across, 4.5 billlion years old, moving at 40,000 miles per hour. Plan on a 9 year trip to reach the comet from earth launch.

This is the comet orbiting the sun in a large elliptical path.  The Rosetta craft with its lander Philae reached the comet and launched the lander to the comet on November 11, 2014 by the European Space Agency at Darmstadt Germany.

Lander Philae took 7 hours to drop 14 miles to the comet surface.  The 220 pound lander weighed as much as a piece of paper due to the small gravity of the comet. Philae bounced thrice because devices which were to secure it to the surface failed to deploy.  First bounce took two hours to hit the surface again. Upon final bounce, the lander ended up in a partially shaded area which prevented solar panels from charging the battery system..  But it was able to complete about 80% of scientific tests (including finding carbon in the atmosphere) before the batteries ran down.  It may be a wait until spring before the lander is oriented such that the sun will reach the charging panels and re- invigorate Philae.  For sure when it nears our sun there should be sufficient light to recharge and continue testing and research on the comet.

These are the experiments that the lander is equipped with :

Lander Instrumentation

 First photo from the comet's surface.  One lander leg is visible sticking up since Philae landed on the other two legs in a shadowy place.  It was still able to perform experiments and relay the results to Rosetta, then a 30 minute trip to earth with the data.

 Mockup of what lander should have looked like upon landing.

Orbiting Rosetta

The equations for elliptical orbits  are fairly basic, even including the mass of the orbiting objects.  But to "slingshot" that object around earth, mars, and the sun, in order to build up the velocity necessary to reach an object 4 billion miles out in 9 years amazes me.  Bravo . . .