The U.S. space agency says it will now try to launch the space shuttle Atlantis on Thursday (12:03 Eastern Time), following the discovery of a problem with a fuel cell that provides electricity to the ship. The delay caused by the fuel cell malfunction follows ten days of postponements caused by bad weather. Space agency engineers are hoping to launch Atlantis this week, so they can resume long delayed work on the International Space Station.
Atlantis will carry a crew of six and cargo bay full of equipment to add to the space station's backbone and power supply.
The U.S. space agency NASA is eager to finish the half-built research outpost. Construction stopped after the shuttle Columbia disaster in February, 2003 forced a long moratorium on shuttle flights, as deputy station manager Kirk Shireman reminds us.
"The last assembly flight was November 4, 2002, so it has been quite a while since we have added on to the mass of the International Space Station," he said.
The two shuttle missions since then - one last month and one a year earlier - were test missions by the orbiter Discovery to check safety improvements.
On this mission, Atlantis is hauling up one of the heaviest loads ever carried into space - a 17-ton segment of the station's backbone, called a truss. This girder-like structure contains a new set of giant solar energy panels, which will reach 80 meters in length when fully unfurled.
It is the second set of four planned solar arrays that will power three science laboratories, two living chambers, and other systems to come.
Installation and setup of the truss and solar panels will require use of both the shuttle's and space station's robot arms and three spacewalks involving four shuttle astronauts.
Mission officials have expressed some concern that the solar blankets could stick together the way another set did on a previous flight. Most of the blankets have been folded in their boxes since before the Columbia accident.
The flight initiates a four-year building marathon to make up for all the time that has been lost. NASA must complete the space complex in the 16 flights that remain before shuttles are retired in 2010.
The woman who is overseeing the work of the next space station crew, Melissa Owens, anticipates a busy assembly schedule ahead.
"The next six months, and in fact the next year-and-a-half, are going to be really exciting as we watch the complexity and the size of the space station grow," she said. "That complexity and size will allow us to have additional capability for performing our science objectives.
In addition to adding the truss and solar arrays, the Atlantis crew will inspect the shuttle's protective heat shield to see if it was damaged during launch. The inspection has become a routine in-flight task because of the launch debris that doomed Columbia and its crew of seven. That orbiter disintegrated upon re-entry when searing atmospheric gases entered a hole in its wing caused by hard foam insulation that broke away from the external fuel tank during liftoff.