The launch of Rosetta is planned for early next week

The minor repair of thermal insulation on the Ariane 5’s cryogenic core
stage should be completed in time for a rescheduling of Flight 158’s liftoff
next Tuesday or Wednesday morning.

Arianespace Chief Executive Officer Jean-Yves Le Gall said today’s launch
was scrubbed after a routine pre-launch inspection found a small piece of
foam that had broken free from the cryogenic core stage.

This inspection – made at the mobile launch table on which Ariane 5 is
installed – occurred several hours before the scheduled liftoff. The finding
led to the creation of a team to review the situation – which eventually led
to the delay.

The small piece (approximately 10 X 15 cm. in size) apparently separated as
a result of temperature changes that occurred with the fueling and
de-fueling of Ariane 5’s cryogenic stage. The stage carries 155 metric tons
of the cold cryogenic propellant (liquid oxygen/liquid hydrogen), and it was
emptied after the first launch attempt was postponed on February 26 due to
weather conditions.

Ariane 5 will be moved from the ELA-3 launch zone back to the Final Assembly
Building today, where the missing insulation will be replaced. A complete
inspection of the thermal insulation will be made before authorization is
given for Ariane 5’s move back to the launch zone.

Le Gall said the phenomenon of thermal insulation breakaway has occurred in
the past, including on Ariane 4’s cryogenic third stage. "The situation is
well identified and the repair is simple," Le Gall told reporters during a
briefing this morning at the Spaceport.

Both the launcher and its Rosetta comet-chasing spacecraft are safe and in
good condition, he added.

Rosetta was developed for the European Space Agency, and the deep-space
probe’s launch period extends through March 17 – providing plenty of time
for rescheduling the liftoff.

"I want to thank Arianespace for the decision to not take any risks with our
mission," said ESA Director General Jean-Jacques Dordain. "A few extra days
on Earth for our ‘baby’ will have no consequence for this 10 year mission."

Ariane 5 will place Rosetta on an Earth escape trajectory that will lead to
its encounter with Comet Churyumov-Gerasimenko in 2014.