Astronaut Mike Fossum, right, and Japan Aerospace Exploration Agency astronaut Akihiko Hoshide, both work on middeck of Space Shuttle Discovery during flight day two activities

Astronauts on the U.S. space shuttle Discovery are making preparations for Tuesday's spacewalk to attach a new laboratory to the International Space Station.

Mission specialists Mike Fossum and Ron Garan will unlock the $1 billion Japanese Kibo laboratory from the shuttle and prepare it for installation.

They will also help remove an inspection boom from the station and clean debris from a jammed joint on a solar panel.

Meanwhile, astronauts inside the ISS will use the station's robotic arm to remove and install the bus-size laboratory.

Back on Earth, NASA officials say Saturday's shuttle lift-off caused unprecedented damage to its launch pad.

They say most of the damage was to the flame trench, which helps deflect heat from the shuttle's rockets.

Despite the problems on the ground, officials says they do not believe the shuttle suffered any damage from falling debris.

The shuttle's pilot performed a backflip before docking Monday, to allow the station crew to look for damage to the underside of the shuttle.