Comet Landing

Hitting a Bullseye on a Moving Target

Rosetta Welcome_to_a_comet
The first image from the Philae probe.
  • Why it matters

    Why it matters

    The successful landing of a scientific probe on a speeding comet a half billion kilometers from earth could boost support for research and further missions at the European Space Agency.

  • Facts

    Facts

    • The Rosetta journey took 12 years and used the gravitational fields of several planets for propulsion.
    • Rosetta’s Philae probe landed on Comet 67P/Churyumov-Gerasimenko, which orbits the sun every 6.5 years.
    • Mission scientists at 2p.m. CET today will announce whether Philae survived the landing intact.
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  • Audio

    Audio

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Throughout history, the sighting of a comet was often seen as a sign of doom.

But this week, when scientists at the European Space Agency’s mission headquarters in Darmstadt, Germany, landed a probe on a distant, speeding comet, the news was greeted with delight.

The European agency on Wednesday confirmed that its probe, called Philae, had successfully detached from the Rosetta space craft and was heading towards Comet 67P/Churyumov–Gerasimenko 510 million kilometers (316 million miles) from Earth.

In dramatic photos released Thursday morning in Europe, Philae’s camera, developed in Germany, took vivid images of an otherworldly landscape of curved mesas and cliffs, highlighted against the naked illumination of the sun millions of miles away.

In a preliminary assessment, scientists said that Philae bounced three times before settling on the speeding ball of rock, gas and dust, but had apparently achieved a stable position to take photos and commence with nine on-board experiments.

The space engineers were not sure at first if the washing-machine sized craft would land.

Philae was supposed to use a combination of harpoons and thrusters to counteract the recoil of the harpoons, and land smoothly on the surface. But at the last moment, the thrusters appeared to fail. Despite that, Philae seemed to land successfully.

Scientists initially had announced Wednesday that they were receiving data from the lander’s nine experiments, but hinted that the craft had had a rough landing — ending up perhaps on its side, its back, or not being fully tethered to the speeding comet.

By late Wednesday, Philae lost its line of site contact with the orbiting Rosetta craft and communications back to earth — which took 28 minutes — were interrupted.

But photos released this morning in Europe by the agency appeared to confirm that Philae had largely surived its complicated landing intact, and would be in a good position to accompany the comet on its journey around the sun.

 

According to the European Space Agency’s website, a news conference has been planned for 2pm CET, 8 a.m. today in New York.

Scientists are still analyzing just what happened, but the elation over landing in some form on the comet was palpable in Germany and in France, where the mission was jointly planned and executed.

Alvaro Giménez, ESA’s director of science and robotic exploration, said the successful landing was a “game changer in cometary science and space exploration.”

The next few days are crucial. Philae will be able to gather images for 2.5 days, and then, if its solar panels and rechargeable battery work successfully, could operate until March. Rosetta will also continue to follow the comet for more than a year, observing its activity.

The probe is meant to gather and analyze data on the comet, a 4-kilometer long piece of hurtling rock and dust that scientists believe was produced during the early days of the universe.

“Rosetta is trying to answer the very big questions about the history of our solar system. What were the conditions like at its infancy and how did it evolve? What role did comets play in this evolution? How do comets work?” said Matt Taylor, a Rosetta project scientist.

 

ESA’s Rosetta mission has soft-landed its Philae probe on a comet, the first time in history that such an extraordinary feat has been achieved. Source: ESA

The comet landing was well over a decade in the making.

Comets are one of the mysteries of the solar system. They are often visible from earth and some scientists believe that life on earth began when comets crashed onto the earth’s surface, introducing water, the key ingredient of life. In 2004, the ESA launched Rosetta in the hopes that it would track a comet and launch a probe to land on its surface.

Rosetta has been flying near the comet for months collecting images that helped scientists choose a suitable landing site. The first images showed the comet surface covered with boulders, cliffs and precipices, with jets of gas and dust streaming from the surface.

The landing was a major boost for the ESA and pan-European projects.

In the years after World War II, European governments realized that many of their best scientists were leaving to work in the United States or the Soviet Union and decided to cooperate to compete in the field of space exploration.

In 1961, scientists from 10 European countries set up cooperative organizations to carry out space exploration. The space operations center opened in Darmstadt, a picturesque city in southern Germany just outside Frankfurt, in 1967.

The European national agencies combined to form the European Space Agency in 1975.

France and Germany are now the ESA’s biggest supporters in terms of cash and investment. Several countries, including France and Italy, had fallen behind on their payments to the ESA.

But the agency’s head of corporate planning and control, Gerhard Kreiner, said at the start of the year that all member countries had made significant efforts to repay the amounts they owe, despite the ongoing financial crisis in the euro zone.

Since 2004, the European Union has financially supported the space agency. However, there are now tensions over just how far the ESA, which includes a handful of countries not in the European Union, should come under the control and influence of the bloc.

Key tensions include how countries contribute to and benefit from the ESA’s work.

ESA Confirmation_of_separation_of_the_Philae_lander_from_Rosetta
Smiles in the Main Control Room at ESA’s Operations Centre, ESOC, as separation of the Philae lander from ESA Rosetta orbiter is confirmed. Source: ESA – J. Mai

 

Germany, which has one of Europe’s most successful space projects, both through the ESA and the German Aerospace Center, known as DLR, wants the ESA to maintain its independence, and to keep its principle of geographical return, where a country that invests in an ESA project will get back returns proportionate to what it put in.

The European Union wants investments and returns to be calculated along different lines.

There in an ongoing rivalry between the space agencies on either side of the Atlantic.

In 1989, NASA had sent an unmanned space craft named Galileo to land on the surface of Jupiter. It landed successfully in 1995.

Europe has also been racing to compete with the United States in satellite and space technology. It is developing its own global navigation satellite system, also called Galileo, which will provide a home-grown alternative to the United States’ GPS and Russia’s Glonass tracking systems.

The success of Rosetta, named after the Rosetta Stone, a rock with text written in three different scripts that provided a key to understanding Egyptian hieroglyphics, is something that will strengthen the hand of the ESA and its operating models in the coming years.

 

Meera Selva is an editor at Handelsblatt Global Edition in Berlin. To contact the author: selva@handelsblatt.com.

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