Dec. 29, 2006 — It has been nearly four years since the tragic Columbia accident rocked NASA to its soul and triggered a decision to set a retirement date for the aging space shuttle fleet.
But NASA closed 2006 on a high note, having completed three shuttle missions in five months — just like in the pre-Columbia days — including what many managers considered a linchpin flight to rewire the outpost’s electrical system.
The return of shuttle Discovery a few days before Christmas prompted an outpouring of gratitude for the team that pulled off the mission and an even greater sense of relief.
During that time, the U.S. space agency was charged with reviving the program, making it safer and restarting the complicated and intricate task of building the International Space Station in orbit.
But the pressure will resume soon.
Adjusting to Meet Deadlines
With limited flight opportunities for the shuttles available until 2010 when the ships are removed from service, NASA had to slice into the number of missions planned to complete station assembly and resupply.
Managers shifted many complex tasks, such as reconfiguring the station’s cooling system, from shuttle astronauts' job lists to the station's crew to handle.
"There are tremendous challenges in front of us," said Bill Gerstenmaier, NASA's associate administrator for space operations. "I think we need to not be disappointed if things don’t go exactly the way we planned."
Station commander Michael Lopez-Alegria and newly arrived flight engineer Sunita Williams are preparing for a tightly choreographed trio of spacewalks packed into a week in early February. The work, which will be done without a space shuttle present, will prepare the station for two more sets of solar array wings and a connecting node, the final piece of U.S. hardware.
Before the end of 2007, NASA also intends to fly and install the first module built by station partners in Europe and Japan. The European Space Agency’s Columbus laboratory has a flight slot in October.
"That is what we have been waiting for, for quite some time," said Sigmar Wittig, chairman of the European Space Agency Council. "This will be giving us the opportunity for real European science.
There are hundreds of experiments, which are waiting."
The Post-Columbia Reality
NASA had planned to be long finished with station assembly by now, but work halted after the Feb. 1, 2003 Columbia disaster. NASA had failed to recognize that insulating foam falling off the shuttle’s external fuel tank during launch posed a threat to the orbiter and crew.
The foam that hit Columbia’s wing during liftoff, pierced the heat shield on the ship’s wing, allowing superheated atmospheric gases to blast inside the structure as the shuttle returned to Earth for landing. Seven astronauts aboard were killed as the shuttle broke apart over Texas and Louisiana.
NASA grounded the fleet for 2.5 years to improve the tanks and implement new safety procedures, such as inflight inspections of the heat shield. The accident also prompted the United States to shift its human space program from low-Earth orbit research aboard the shuttle and station, to exploration of the moon and other destinations.
