As everyone recalls, last November the Philae Lander made an uncontrolled and unplanned arrival on 67P/CG, ending up in a shady spot. With insufficient sunlight, the lander shutdown, hoping that it would awaken as the comet approached the sun.
Indeed, Philae did wake up, and sporadic contact was established in July,
Last week the Philae team posted a detailed recount of the contacts with Philae.
We now know that the lander is definitely askew, on its side and possibly blocked by surface features. This has made it difficult for the orbiter to “see” the signals from the lander. In addition, as the sunlight increased approaching perihelion (good for the lander) the gas and dust emissions increased sharply, forcing the orbiter to pull higher.
The post tells an interesting story of how the limited data was interpreted in the face of sporadic contact and failing equipment. This is fascinating real life engineering, though unfortunately the results have been disappointing.
Maneuvering the Rosetta orbiter to try to contact Philae precluded other scientific observations, and by July 25 it was necessary to break off and take up important data collection around perihelion. At the same time, the orbiter has moved higher to stay clear of the dust.
At this point, there is no chance of contacting the lander. There will be one last opportunity late this year, and the team is working to prepare a strategy based on what can be gleaned from the data returned so far.
This is an amazing story, even if there is no Hollywood ending. Philae was an awesome machine, and kudos to the folks who have been working so hard to learn what happened to it.