Philae

Philae is an ESA lander that accompanied the Rosseta spacecraft on its mission until it landed on comet 67P more than 10 years after it launched from The Guiana Space Center in French Guiana. It landed on the 12th of November 2014 achieving the first ever soft landing on a comet nucleus, obtaining the first images of a comet´s nucleus.

The spacecraft is tracked, managed and operated from ESOC space center in Germany. It has been the first spacecraft to be able to make a direct analysis of a comet with several instruments, sending back information to be able to determine the composition of the comet´s surface.

It gets its name after the philae obelisk which was used along the rosseta stone to decipher Egyptian hieroglyphics. As of today Philae remains shut off and in safe mode due to not enough sunlight and disorientation after landing in an unplanned site. Because of the little light it receives it is currently incapable of communicating with its sender Rosseta. Mission controllers at ESOC hope that by August this year it will receive enough energy to power up and reconnect with Rosseta.

Philae's scientific goals focus on " elemental, isotopic, molecular and mineralogical composition  of the cometary material, the characterisation of physical properties of the surface and subsurface material, the large-scale structure and the magnetic and plasma environment of the nucleus".

The primary battery was designed to be able to power Philae's instruments fore more or less 60 hours. ESA expected that a secondary battery would be at least partially filled by the numerous solar panels attached to the outside layer of the spacecraft, but the limited sunlight (90 minutes per a 12.4-hour comet day) at the unfortunate, unplanned landing site is inadequate to capture sunlight, at least in this phase of the comet´s orbit. On the morning of the 14th of November 2014 the battery was supposed to last until the end of the day. In order to use as least battery as possible the first data obtained was from instruments whose measurement procedures did not require mechanical movement, being able to get 80% of the initially planned scientific observations. During the "evening session" of that day Philae was raised 4 cm (1.6 inches)and rotated its body 35 degrees to a more favourable position for the largest solar panel of all, to try and capture as most sunlight as possible in the future. This operation of lift up and rotation used up quite a lot of battery, forcing a shut down of all instruments . Contact was lost on 15th of November at 00:36 UTC. The German Aerospace Center's spacecraft manager stated: "Prior to falling silent, the lander was able to transmit all science data gathered during the First science Sequence... This machine performed magnificently under tough conditions, and we can be fully proud of the incredible success Philae has delivered.