NASA to Hustle on Space Station

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.

The agency must first make good on its promise to build the station, which is estimated to cost $100 billion and includes contributions from the United States, Russia, Europe, Japan and Canada.

In addition to the technical failures that led to Columbia’s demise, the board that investigated the accident faulted NASA for poor management practices and succumbing to schedule pressure.

With the clocks now ticking toward the shuttles’ retirement, NASA will be walking a fine line to balance a healthy flight rate without incurring too much risk to the station program overall.

One factor that has been taken off the negotiation table completely, however, is crew safety.

No Compromise on Safety

During Discovery’s final flight of 2006, for example, managers debated about whether to keep the ship and its crew in space an extra day to complete a station construction job.

After days of discussion, the mission was extended. But instead of passing up a day set aside for a final inspection of the ship’s heat shield, NASA decided to give up one of the two days reserved for landing postponements.

As landing day approached, flight directors started getting grim weather forecasts for both the Florida prime landing site as well as the backup strip in California. NASA mobilized teams to a rarely used site in New Mexico, realizing that if Discovery had to land there the shuttle’s future flight schedule would take a hit.

Landing day dawned with rain and clouds in Florida and high winds in California. As the hours passed, however, NASA caught a break from the notoriously fickle weather in Florida and was able to direct Discovery to a landing at its home base.

By the time the astronauts got off the shuttle for a traditional walk-around their ship, the rain was falling and they huddled under Discovery’s belly, talking with officials who had gathered on the runway to welcome them home.

"In this case, it turned out well," Griffin said. "Sometimes it may not. We do have a good bit of contingency built into our flight rate to allow us to finish the station in time, but it is these kinds of calculated risks that give us the best chance to complete the space station."

NASA's first shuttle mission of the year is slated for mid-March.