The Philae lander, which made history by landing on comet 67P/C-G this week, has unfortunately found itself sitting in the shadow of a cliff. Its solar panels can’t see the Sun, and thus its battery reserves are quickly running down.
Sadly, even space agencies with budgets of tens of billions of dollars are not immune to the pathetically lacking longevity of batteries. The European Space Agency will now try a series of heroic measures to try and keep Philae alive, but there’s the regretful possibility that Friday night — tonight — will be the last time we hear from the probe, Extremetech reported.
On Tuesday morning, Philae safely separated from the Rosetta mothership and began a seven-hour descent to the surface of comet 67P/Churyumov-Gerasimenko. It was all going perfectly — Philae was on a perfect trajectory to land in exactly the right spot — but then its landing thruster didn’t work, and its grappling harpoons failed to fire. Philae bounced back off the surface of the comet, floated around for a couple of hours in the comet’s weak gravity, bounced off the surface again, and then eventually landed about 0.6 miles (1 km) away from the original landing site. We don’t actually know where Philae landed, though Rosetta is using its high-res camera to look for it.
One of the last images of Philae as it descends towards comet 67P, taken by Rosetta
Unfortunately, with all the uncontrolled bouncing and distinct lack of harpooning, Philae appears to have ended up in the shadow of a cliff — a shadow that prevents the lander from using its solar panels effectively. This is a problem as Philae’s primary battery is only good for about two days of usage — or, in other words, it’ll die very soon unless the ESA can somehow get some sunlight onto those solar cells.
The ESA, for its part, doesn’t seem too phased by the dire circumstances. Basically, it’s a miracle that Philae landed at all — and despite the rough landing, the ESA is reporting that all of its scientific instruments are working and returning invaluable scientific data. Every instrument, that is, except for the drill, which ESA hasn’t used because the torque could destablize the lander (that’s what the harpoons were for). Now, however, with time running out, the astronomers at mission control will probably risk it anyway — the scientific payoff from drilling into a real, live comet is just too big to pass up.
This is what comet 67P looked like, when Philae was 40 meters away from its first landing
Philae’s first panorama of the comet 67P/C-G. The ESA has superimposed a drawing of Philae to show its orientation. As you can see, it’s pretty shadowy there.
Before Philae runs out of juice, the ESA will instruct the lander to turn its body, hopefully bringing its main solar panel into the life-giving gaze of the Sun. If that doesn’t work, there are two other options for Philae: a) Go into hibernation mode and hope wait for sunnier times (which may occur as the comet gets closer to the Sun) — or b) Throw caution to the winds and drill into the comet — for science! — on the assumption that it might be the last thing it does. Some engineers at the ESA are also mooting a third option — somehow using Philae’s moving parts to “hop” out of the cliff’s shadow — though, given how we know almost nothing about the lander’s current location or orientation, suspectedly that’ll be a last resort.
If Philae does die tonight, it won’t be in vain. The lander has already returned a lot of valuable scientific data, and surely the ESA will try to use the drill tonight, in a last-ditch effort to eke out as much science as possible from the comet. At the end of the day, the fact that we’re getting any data at all — that man managed to land on a 2-mile-wide comet after a 10-year, 4-billion-mile journey across the Solar System — is pretty awesome.
Good luck, Philae.