Philae comet probe got down without harpoons ESA head of mission operations Paolo Ferri has said that the harpoons meant to anchor the Philae lander to the surface of Comet 67P/Churyumov-Gerasimenko did not actually fire as they'd thought earlier. Artist's impression of Philae on Comet 67P But regardless, the craft is reporting that it’s stable on the space-rock, so …
"Since the harpoons failed to fire, the lander is likely anchored by its three ice-screw legs."
Or possibly fewer than three. It will be important to find out (if possible) why the thruster had failed and why the harpoons didn't work. For now, we can breathe a sigh of relief and raise a glass, or three.
I saw a news item that featured a duplicate of Rosetta in a test/simulation chamber and I'd be surprised if they didn't have a duplicate of Philae available for prodding and poking. If you're building something like these, the marginal cost of making two instead of one (at the same time) is a very small fraction of the project budget.
They could give a duplicate Philae (or its component subsystems) a good hammering in a test chamber to see what failure modes are induced under what conditions.
IIRC, for any piece of space hardware like this they build multiple copies of each component anyway --- to test against each other, and in case someone drops one (it's happened, they've dropped a complete $300M satellite on the assembly room for before), and to give them something to try potentially risky procedures on, etc. So yeah, I'd be totally unsurprised to hear that they have a complete identical Philae in a lab somewhere.
There is a duplicate of Philae in the lab, I heard an interview with one of the scientists who designed the mission on the Quirks and Quarks podcast last week.
He was saying that the spent the last ten years learning exactly how the instruments would work and what they could learn from them. He was joking that it wasn't all "putting my feet up on the desk and waiting for ten years to go by". Good interview!
From other projects I've read about; they'll build many copies of a space craft: One primary to be launched, a second one in case the first is found to be defective on or near launch.
Then there will be several engineering copies to test one or two pieces. None of these will be full copies, but you can assemble one form multiple models with dummy components taking the place of the systems not under test. One might be uses solely to test the drills, another the landing gear, and maybe a third that is the drill and landing gear sections. These copies only get used once since they get pushed through stress testing and you're not going to test against a already-stressed component.
Brilliant stuff - and it is beyond me how you navigate such a small craft millions of miles away so accurately onto a hurling rock, and it all (nearly) works perfectly.
I am as star struck now as I was during the Apollo missions, which where perhaps a lot more brilliant as I was a 10 year old kid.
It's even more incredible than your summary. The craft flew over 1 beeeellion er miles or km (probably km) and used Earth and Mars multiple times to slingshot. It was put into hibernation and woken up. And it did this over 10 years.
Now that's ambitious and frankly beats the shit out of some science fiction for being a bit conservative.
It was working brilliantly until the computer threw a wobbly, which just goes to show that robots should not be used for space exploration. They are untrustworthy, mutinous, murderous and creep out the humans with their voices just to be gits.
They are no good at amateur radio repair either.
You could do a lot worse than clicking here.
As of the time of posting, it looks like the link has gone kaput. It was downlink-only earlier, at some slow speed. Wonder if they can bounce the signal off other spacecraft in the DSN?
If the rovers had arrived with their wheels broken maybe I'd concede the point. The rovers wore out during the mission, while working hard. This poor little lander's comet acquisition and snaffling machinery broke down en route.
And now they can't even figure out if the screw piton legs have worked or whether the lander simply bounced until it got fouled in the comet.
Make them give back their grant money, I say.
"You might find a few engineers taking exception there, what with the machine managing to perform even though it was multiply knackered after many years in a brutally harsh environment."
Presumably these would be the same engineers who were asked to design a harpoon scheme and thruster that would survive the journey? Because, you know, 0/10 right there.
Or was this a six-month flight that fell foul of the Google Maps navigation system?
Conceived in the 80's, funding began in the 90's and launched in 2004, where it travelled for 10 years to reach a comet that orbits from Jupiter to the sun. Major crises averted, now we wait 12 hours for this rock to rotate to see if it's still there. Sounds like a scientific soap opera. Tune in tomorrow. Same Bat-Time, same Bat-Channel.
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