The Rosetta Mission

It was a mission that will go down in history, though perhaps not as amazing as man's first step on the Moon, but when the European Space Agency's one-billion-pound Rosetta probe swooped down over comet 67P and, from an altitude of 20km, released the robotic lander known as Philae, on descent to its surface, it was an incredible scientific feat. It may not have been 'one step for mankind' but that bounce over the comet culminated into a success after ten years of planning to occur beyond the orbit of Mars watched by the world. 

What was it?

The International Rosetta Mission was approved in ESA's Horizons 200 Science Programme 21 years ago in 1993. In those decades, scientists and engineers all over the world built an orbiter and lander for this expedition in order to discover and explore the secrets of the comet. Rosetta would, once landing on the Comet 67P, cross the asteroid belt and travel into deep space, more than five times the Earth's distance from the Sun. In 2015 when the mission will draw the close, the spacecraft and comet will have circled the Sun and be on their way out of the inner Solar System. The success of the mission is historic one. Rosetta will be the first spacecraft to orbit a comet's nucleus, fly alongside a comet as it heads towards the inner Solar system, and examine from close proximity how a frozen comet is transformed by the warmth of the Sun. One arriving at the Comet 67P, the orbiter will despatch Philae, the robotic lander, and its instruments will obtain images from the comet's surface and analyse its components. Once passing through the main asteroid belt, Rosetta will the first ever spacecraft to fly close to Jupiter's orbit using solar cells as its main power source.

Why do it?

Mainly to investigate the components of the comet that will be extracted by the lander and then fed back to Earth. The elements that make up the comet: complex organic molecules rich in carbon, hydrogen, oxygen and nitrogen, are the elements that make up nucleic and amino acids, the essential elements for life as we know it. Analysis of these elements may help answer some fundamental questions such as: did life on Earth begin with the help of comet seeding?

What happened?

The landing was not smooth: it bounced twice and culminated into a triple touchdown on Wednesday. Resting on its side, lodged in the shadows, the lander sent back historic images taken from the surface of the comet. As its landing left it surrounded by rocks, Philae then was only able to receive just 1.5 hours of sunlight instead of the expected 6 to 7 hours. However, despite this, the lander deployed a 1.2 metre arm and drill, accomplishing its primary mission to last around 60 hours on its initial battery charge and obtaining data on the surface of the comet. The drilling operation was deployed in order deliver samples to onboard instruments. The Cometary Sampling and Composition experiment instrument was chosen in order to study the first samples, and it works by detecting and identifying complex organic molecules from their molecular composition. The instrument detected and analyzed these moles of gas that naturally came off the comet's surface. The lander, however, did run out of power although there were some attempts to move it towards better sunlight in order for its solar panels to obtain more energy. Though the lander has now effectively gone to sleep, when the comet heads for its approach to the Sun that will occur in August 2015, by bringing the lander closer to sunlight, Philae may then power up.

What will happen next?

Dear Philae provided everything expected from it before it powered down, transmitting all the science data in the first sixty hours. As well as sending images and exercising of its Consert instrument that try to discern its internal structure, it can possibly be used to triangulate its precise position. Knowledge of its location would enable engineers to understand its future prospects. For now, Rosetta will continue to observations the 67P comet and we can admire the captured images



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