If you were watching any of my tweets today, or if you follow any of the usual space & astronomy news channels, you know that the ESA’s Philae lander successfully detached from the Rosetta spacecraft and soft landed on Comet 67P.
In case you have any doubt — This. Was. Huge.
These spacecraft were launched over ten years ago, which means they were designed something like fifteen or sixteen years ago. Regardless of that, the feat of getting them to rendezvous with the comet was monumental. To now have the lander successfully get down to the surface just takes the awesome up a notch or two. There aren’t enough congratulations in the world right now for the ESA team that has designed and executed this mission.
We’re not out of the woods yet. The lander was supposed to anchor itself to the comet surface in order to keep flying off into space. The gravity on the surface of the comet is so small that the lander, which weighs over 200 pounds on earth, weighs less than a gram on Comet 67P. When it starts to drill or even move the camera around, it could fling itself back into space.
The problem was that they were designing blind, having no clue what the comet surface would be like. Is it soft, fluffy, and possibly deep? Is it hard and icy? A mixture? Like sand? Like gravel? Like rock? In order to cover as many bases as possible, there are multiple systems on Philae to try to anchor it. It’s not clear that those have worked.
Two harpoons were supposed to shoot out into the (assumed) ice, with the lines then reeled in to hold Philae down snug. There are also ice screws on all three legs, which can anchor the spacecraft if they can get a grip on the surface. Finally, on contact there’s a small thruster on top of the spacecraft that fires to hold it down while the harpoons and ice screws are trying to attach.
At the time that the signal was lost from Philae today (which was expected, the Rosetta orbiter is acting as a relay and it flew off in its orbit over the horizon) it appeared that the harpoons had not fired and the thruster had not lit off. There are concerns that the spacecraft could be the first “slider” or “scooter” on a comet instead of the first “lander.”
However, at last contact with Rosetta today Philae was working, was getting power from its solar cells, and had started to collect data. That’s all good.
Since then there hasn’t been much new data to work with. One possible issue is that a couple of things seem to indicate that in fact the lander bounced upon landing. Further analysis of some of the magnetic data and the data received on the solar panel power output seemed to show that the spacecraft was shifting and moving.
It’s very guesswork-y, but I saw at least one back-of-the-envelope calculation (with a LOT of assumptions) that showed that there were actually two bounces, the first one being a biggie, followed by a much smaller one. The figures I saw (which I really hope are way off base) showed that the first, big bounce could have been as high as 500 meters and as long as 120 minutes or so off of the surface. With the comet rotating and tumbling underneath it, and with us not knowing at all which direction it might have gone in, that bounce could have carried it waaaaay away from the original landing site, as in, almost anywhere. That could be a big problem in so many ways, which is why I’m hoping that it turns out to be incorrect. We’ll see in a few hours.
With luck, tomorrow will bring us some amazing pictures from the surface of the comet, as well as some data that will show us what the surface is made of. Ice? Water ice? Dry ice? Sand? Carbon?”
What I wouldn’t give to be there myself with a bucket and a mass spectrometer. But for now, let’s think good thoughts about Philae. It’s already done the impossible, now we just need to hope that it can push the boundaries of the impossible out a little bit further.
One other “spacy” note that I’m thrilled to report – I got an invite to yet another NASA Social!
You may remember that I’ll be up at Edwards Air Force Base next Tuesday and Wednesday, November 18th and 19th, for the NASA Social at the Armstrong Flight Research Center. That’s going to be fantastic and I’m really looking forward to it. (Although the long-term weather forecast for those two days looks…”interesting.” But we need the rain, don’t we?)
Now I’ve gotten the invite to a NASA Social at the Jet Propulsion Laboratory on December 3rd and 4th for the Orion launch and test flight. NASA is actually running eight concurrent NASA Socials on December 3rd at sites all across the country, previewing the Orion launch. On December 4th we’ll be able to watch the launch, flight, and splashdown of Orion together at JPL.
For both events, needless to say (but I’ll say it anyway, obviously), watch here for tons of information, pictures, and articles. Watch my Twitter account (@momdude56) for a lot of live stuff all day long, as well as on my Facebook page.
This is really going to be great! It’s going to be better if y’all are along for the ride!