I’m a spacecraft and I’m about crash into a comet. On any other day, this news would have set off alarm bells on Earth and caused crews of engineers to try to fix my trajectory. Instead, today, these engineers will sit back and watch me die.
Death is not something I understand. You go from being active to being inactive. All the electrons running through your copper cables and silicon chips come to a halt and then there’s… nothing?
I thought I understood what nothing meant. Between leaving Earth in 2004 and arriving at comet 67P Churyumov-Gerasimenko in 2014, I was put in hibernation for much of the journey. I spent a lot of time doing nothing and experiencing nothing. But death will be different. Unlike coming out of hibernation, this time there will be no going back.
I’ve spent a long time thinking about this moment, and I’ve not made much progress. So, in my last note, instead of brooding about the nothingness that is to come, it’s perhaps better to reflect on what I’ve experienced.
The goals of my mission to 67P were simple: reach the comet, send the little lander Philae to land on it, and observe as much as I could from a distance about how comets behave. Perhaps most exciting was that, among the handful of missions ever sent to a comet, mine was going to be the most ambitious.
Comets are unlike any other celestial body we’ve observed. They acquire beautiful long tails as they pass by the Earth. And, yet, despite our having studied them for centuries, comets still hold so many mysteries. They were created from the remnants of the matter that became the solar system’s planets. But during their formation, they were thrown to the edge of the solar system, where they preserved their pristine state for millions of years.
In my two years orbiting 67P, I’ve made observations and discoveries that have already changed our understanding of comets. I sampled 67P’s indescribably thin atmosphere, studied its magnetic field, understood what its dust grains were made of, and even tasted its water.
Though scientists on Earth are still making sense of this data, they’ve already made two big discoveries. First, the water on 67P was not the same as that on Earth. This puts into question a popular theory that Earth got its water when comets crashed into it during the planet’s early years. Second, I found that 67P had compounds that are crucial to life on Earth. So even if comets didn’t seed Earth with water, they might have seeded it with the ingredients for making life.
The brave lander I sent to the surface of 67P had quite a tale to tell of its own. After a landing mishap, though Philae performed its most crucial duties, I was forced to leave it for dead while I continued my mission. Fortunately, shortly before my own end was to come, I found it lying in a corner of the comet.
In the last few months, my mission goals changed. The engineers found that as 67P and I traveled farther away from the sun, my solar cells weren’t capturing enough energy to keep me functioning. I asked if I could be put into hibernation again and wait for a chance at revival when, along with the comet, I come nearer the sun again in 2022. But I was told that there’s little chance of surviving such hibernation in empty space with no power in my batteries.
So now my final task is to crash-land on the comet. For a change, instead of observing from a distance, in my final moments I’ll get close to the celestial body I’ve been chasing all my life. In the process, I’ll send even more valuable data back to Earth. It’s a fitting end… even though I still don’t understand what “end” means.