Just three short months ago, the ESA's Rosetta spacecraft made history by landing its Philae Lander on the surface of a comet. However, that touchdown didn't go as planned, and after bouncing across Comet 67P/Churyumov-Gerasimenko, the lander ended up far from its initial target and eventually powered down.
Although the ESA has a general idea of where Philae ended up, Rosetta hasn't been able to find it from its current position in orbit around the comet.
Because of that, Rosetta's scientific team is debating on whether they should send Rosetta closer to the comet next month in a better effort to find Philae.
However, such a mission comes with risks, including using up some of Rosetta's valuable fuel supply. If Rosetta swoops in closer to Comet 67P to hunt for Philae, it loses the fuel it needs for a future mission of a planned flyby that would put it on the sunlit-side of the comet, allowing for better imaging.
Also, as Comet 67P gets closer to the sun, it is now more active, which means jets of gas and dust are flowing all around it. That debris could cause damage to both Rosetta and its instruments.
"If we are going to change plans to target looking for the lander, that impacts some of the goals we had planned," says Joel Parker, a member of the Alice instrument team for Rosetta.
Rosetta's team must now weigh the pros and cons of such a mission. If Rosetta found Philae, they might determine if the lander will possibly wake up once the comet gets closer to the sun. But that means seeing Philae's position on the comet, as well as seeing if its solar panels can catch enough sunlight to get its power up and running again.
There is also data that Philae gathered in its short time awake on the comet that still needs interpreting. Knowing its exact location would help scientists better understand that data.
Of course, even if scientists approve a new mission for Rosetta for finding Philae, there's no guarantee of success. Because of the way Philae landed after bouncing on the comet's surface, it could be impossible for Rosetta to spot.
Regardless, the main hope of the ESA team is that Philae will wake up in May. If that happens, the lander can continue with its unfinished scientific missions that it began three months ago before it went to sleep.
The ESA plans on making a decision on a potential Philae-finder mission within the next few days.
[Photo Credit: DLR German Aerospace Center]