Leonard David's INSIDE OUTER SPACE

This series of 19 images, acquired by the Rosetta orbiter’s Optical, Spectroscopic, and Infrared Remote Imaging System (OSIRIS) on 12 November 2014, shows the Philae lander during its descent towards Comet 67P/Churyumov-Gerasimenko.
Credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA.

Europe’s Philae lander sits somewhere on the surface of Comet 67P/Churyumov-Gerasimenko – its battery depleted as of November 15, 2014.

But there are high hopes that the lander can muster up sufficient energy to “phone home” as the comet continues its journey towards the Sun.

According to Project Manager, Stephan Ulamec from the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; (DLR): “We will start looking to see whether Philae has been exposed to enough sunlight and been able to acquire sufficient energy as early as the end of March.”

Needle in a haystack

Philae is no bigger than a washing machine making it extremely difficult to spot the lander via the European Space Agency’s Rosetta orbiter that is circling the comet. However, that optical search is viewed as looking for a needle in a haystack.

This image was acquired by the Rosetta orbiter’s Optical, Spectroscopic, and Infrared Remote Imaging System (OSIRIS) at 18:18 CET on 12 November 2014. The Philae lander is visible at the intersection of the red lines – above the crater rim.
Credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA.

Philae touched down on Comet 67P on November 12, 2014. Due to the comet’s low gravity, the tiny spacecraft made a triple landing then carried out more than 56 hours of scientific work.

ESA researchers have determined that the lander is located in a shadowed position close to the rim of a crater on the “head” of the comet, adjacent to its equator.

Philae’s final landing site has now been named after the ancient Egyptian city of Abydos.

Wake up work schedule

If Philae does wake up, it is programmed to listen for the Rosetta orbiter and to transmit a signal at regular intervals.

Philae lander may wake up early next month. This composite image was created using images acquired by the Rosetta orbiter’s Optical, Spectroscopic, and Infrared Remote Imaging System (OSIRIS) on December 13, 2014 from an altitude of 12 miles (20 kilometers) above the final landing site. Philae would be about three pixels across in this image.
Credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA.

According to the DLR, after the initial awakening, it could take several weeks for the lander to generate sufficient power to execute the first commands received from the DLR Lander Control Center and then start charging its battery. Solar cells fitted to the lander are expected to generate needed amounts of power.

By summer, Philae could have stored energy to use its instruments for several hours, notes the DLR.