Falling Foam Causes Concern

A chunk of foam that fell off a rocket forced the European Space Agency to delay the launch of a comet lander Friday for the second straight day. The Rosetta probe -- meant to be the first spacecraft to land on a comet -- had been scheduled to blast off from Kourou, French Guiana, on an Ariane-5 rocket 24 hours after high winds in the upper atmosphere delayed a first attempt.

But scientists called off the start of the 10-year journey after discovering the 4-by-6-inch piece of insulation 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. A large chunk of foam insulation brought down the space shuttle Columbia last year, killing seven astronauts. The foam snapped off the external fuel tank during liftoff and knocked a hole in the wing. Mission officials said Rosetta's insulation likely cracked off the main rocket due to freezing and warming as the super-cold liquid hydrogen and oxygen was added for launch, then removed after the first postponement.

"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. "The spacecraft Rosetta is in good shape and was not affected by these events," he added. The agency says it has a window until March 17 to launch Rosetta toward an ice-caked comet called 67P/Churymov-Gerasimenko.

The space agency originally hoped to begin its mission in January 2003, but its plans were delayed after another rocket in the Ariane-5 family veered off course the previous month and had to be destroyed. The rocket now launching the three-ton Rosetta is a more time-tested version of the one that malfunctioned, and scientists described Friday's problem as minor. In May 2014, Rosetta is scheduled to rendezvous with 67P/Churymov-Gerasimenko and go into orbit. Six months later, the probe will send a box-shaped probe onto the surface as the comet speeds through the solar system at 83,600 mph. Comets formed at the same time as the solar system -- 4.6 billion years ago -- and are believed to hold deep-frozen matter left over from the birth of the sun and planets.

Since comets pelted Earth in the time after the solar system formed, scientists theorize they may have brought some of the building blocks for life, like water and organic materials onto our planet. If the $1.25 billion European mission succeeds, it will be the first time scientists have a chance for an up-close exploration of a comet. Previously, spacecraft have only made brief fly-bys of comets to take pictures. The mission is named for the Rosetta Stone tablet that helped historians decipher Egyptian hieroglyphics.

FMI: www.esa.int