Design
The lander is designed to touch down on the comet’s surface after detaching itself from the main spacecraft body and “falling” towards the comet along a ballistic trajectory. It also will deploy harpoons to anchor itself to the surface, and the legs are designed to dampen the initial impact to avoid bouncing. Communications with Earth will use the orbiter spacecraft as a relay station to reduce the electrical power needed. The mission duration on the surface is planned to be at least one week, but an extended mission lasting months is possible.
The main structure of the lander is made from carbon fiber, shaped into a plate maintaining mechanical stability, a platform for the science instruments, and a hexagonal “sandwich” to connect all the parts. The total mass is about 100 kg. Its "hood" is covered with solar cells for power generation.
It was originally planned to rendezvous with the comet 46P/Wirtanen. A failure of the Ariane 5 launch vehicle necessitated a change in target to the comet 67P/Churyumov-Gerasimenko. The larger comet mass and the resulting increased impact velocity made modification of the landing gear necessary. Besides the changes made to launch time and target, the mission profile remained unchanged.
Read more about this topic: Philae (spacecraft)
Famous quotes containing the word design:
“Delay always breeds danger; and to protract a great design is often to ruin it.”
—Miguel De Cervantes (1547–1616)
“Humility is often only the putting on of a submissiveness by which men hope to bring other people to submit to them; it is a more calculated sort of pride, which debases itself with a design of being exalted; and though this vice transform itself into a thousand several shapes, yet the disguise is never more effectual nor more capable of deceiving the world than when concealed under a form of humility.”
—François, Duc De La Rochefoucauld (1613–1680)
“We find that Good and Evil happen alike to all Men on this Side of the Grave; and as the principle Design of Tragedy is to raise Commiseration and Terror in the Minds of the Audience, we shall defeat this great End, if we always make Virtue and Innocence happy and successful.”
—Joseph Addison (1672–1719)