'Our Lander's Asleep'

The solar-powered space probe launched from the comet-hunting Rosetta craft is currently in long-term standby mode, after its batteries were unable to recharge.

European Space Agency

Updated: 11/14/14, 11:00 p.m.

Even after its gas thrusters and anchoring harpoons failed, the European Space Agency probe Philae still managed to make a historic, albeit bumpy, landing on a comet.

But since the touchdown, times on Comet 67P/Churyumov-Gerasimenko have been arduous for the little lander that could.

First, Philae almost bounced off of the space rock’s surface on its first landing attempt. The washing machine-sized lander, nearly weightless on the comet, hopped more than a mile and a half through nothingness for two hours before landing again, according to the European Space Agency. It then made another smaller bounce, and finally settled in a precarious position—sideways with one leg suspended toward space.

To make matters worse, the solar-powered robot ended up nestled beneath a shadowy cliff. The location prevented the probe from recharging its batteries, which are calculated to drain completely sometime later today. Now, astronomers are racing to get Philae to conduct crucial experiments and beam back results before its batteries die out.

The first panoramic image from the surface of a comet from Philae. Superimposed on top of the image is a sketch of the Philae lander in the configuration the lander team currently believe it is in.  (ESA)

On Friday the lander began drilling 10 inches into the comet’s rock and ice, the AP reported. But communication poses a problem for the team of astronomers charged with talking to the probe. Right now it takes about 28 minutes for mission control to exchange signals with the lander. The team contacts Philae through the Rosetta spacecraft hovering above the comet, but that connection often gets interrupted. In fact, the next time the mothership will have contact with Philae is around 4:00 pm ET today, according to Reuters.

"This will be exciting because we're not sure if the batteries will have enough power to transmit this data," said Stefan Ulamec, Philae lander manager.

In order to retrieve the data, the team said it will have to take some risks. During that communications window, the ESA astronomers are going to attempt a daring “hop” to reposition the probe into a sunnier spot, The Guardian reported. Using the built-in springs in Philae’s legs, the team hopes to fire the probe out of its dark crater. If that fails, The Guardian reported that the team might try to have Philae “cartwheel” out of the crevice by spinning its flywheel. But that may also prove futile if the lander is already out of juice.

If the ESA exhausts all of those last-ditch efforts to prevent Philae from going into hibernation, the team may still have one final opportunity to continue the mission: The comet may pass close enough to the sun to wake up Philae. Comet 67p, which drifts between Mars and Jupiter, is on a six-and-a-half-year orbit around the sun and is currently reaching a close point to the star.

Even if everything fails, and Philae does not survive the night, its creators insist the operation was still wildly successful. ESA said that Philae has carried out about 80-to-90 percent of the science that it was intended to do already.

"Let's stop looking at things that we could have done if everything had worked properly," said flight director Andrea Accomazzo, to the AP. "Let us look at things that we have done: what we have achieved and what we have on the ground. This is unique and will be unique forever."

On Friday evening, the ESA announced that Philae's batteries have indeed been depleted and lander is "asleep." The machine is now in a deep standby mode, and will only make contact again if it manages to catch enough sunlight to recharge its batteries (which may never happen, but is still a possibility.)

However, before shutting down, Philae was able to transmit all of the scientific data it had gathered while on the comet's surface. In addition, the Rosetta craft that delivered Philae will continue to orbit the comet as it continues its journey around the sun.

Lander Manager Stephan Ulamec said, "This machine performed magnificently under tough conditions, and we can be fully proud of the incredible scientific success Philae has delivered."