Europeans Still Hope to Catch a Comet

The European Space Agency's three-ton Rosetta orbiter once again failed to take off on Friday morning after a chunk of insulation fell off the rocket during a routine inspection of the launch pad.

Fearing that ice could form over the hole left in the
insulation and strike part of the rocket if it broke off
after launch, scientists decided to repair the damage and
aim instead for a launch on Tuesday or Wednesday next week.

The postponement is the third for the mission after Rosetta's first scheduled launch in January 2003 was scratched because of technical problems with the carrier rocket. On Thursday high winds delayed the launch.

"Of course we are all disappointed not to see the launch
today, but that is life in this business, Gaele Winters,
the European Space Agency's director of operational and
technical support, said at mission control in Darmstadt,
south of Frankfurt on Friday. "The spacecraft Rosetta is in good shape and was not affected by these events," he said.

The Europeans have until March 17 to launch the orbiter before the window of opportunity closes. After that it may be years before they get another chance to make history by landing on a comet.

Making history

Previous exploration of comets has been limited to fly-bys. Scientists are therefore eagerly awaiting results from Rosetta and its probe Philae, which is scheduled to touch down on Churymov-Gerasimenko in November 2014.

They believe comets -- orbiting clusters of frozen gas and dust which date back to the beginning of the solar system -- may contain vital clues as to how the solar system was formed and maybe even how life itself began on Earth. Some astrophysicists contend that comets' complex molecules may have brought the building blocks for life to Earth when they bombarded the planet in its infancy.

The race to discover what makes a comet has been underway for the past decade:

• 1985 -- NASA's International Cometary Explorer (ICE) traverses the tail of Comet Giacobini-Zinner.
• 1986 -- A small armada of space craft follow Halley's Comet: the Soviet Union's Vega 1 and 2, NASA's ICE, and Japan's probes Suisei and Sakigake. On March 13 and 14, ESA's Giotto comes the closest to the comet with 596 kilometers (372 miles). It relayed images of the potato-shaped nucleus back to Earth and data showing that comets contain carbon dioxide, hydrogen and oxygen -- the building blocks of life.
• 1992 -- Continuing its flight through the solar system, Giotto passes the comet Grigg-Skjellerup within 200 kilometers. ESA technicians reactivate the probe and redirect its antenna.
• 2001 -- NASA's Deep Space 1 probe comes within 2,200 kms of Comet Borrelly. It takes black-and-white infrared photos and collects data about the comet's gases and magnetic field.
• 2002 -- NASA's Comet Nucleus Tour (Contour) is lost after it began a post-launch burn to leave Earth's orbit. It should have researched two comets.
• 2003 -- Rosetta's original launch date to land on the comet Wirtanen is cancelled due to problems with the Ariane rocket.
• 2004 -- NASA's spacecraft Stardust makes the closest-ever approach to a comet, coming within 250 kms of Wild 2 after collecting dust samples from its "coma," the halo-like glow surrounding the comet's head. The samples are due to return in a parachuted capsule on Jan. 15, 2006.
• On Dec. 30, 2004 NASA is scheduled to launch Deep Impact to meet up with Comet P/Tempel 1 in July 2005. It will fire a 350-kilo (770-pound) copper slug at its nucleus and use a spectrometer to analyze the elements of the gases and material that are ejected.