Highlights of the work include installation of a new high-tech cockpit, an improved navigation
           system, and numerous safety, operational, reliability and turnaround enhancements ranging from
           better protection against space debris, to numerous measures to reduce Columbia's weight, thereby
           increasing the vehicle's payload capacity to orbit.

           "In essence, every time a Shuttle leaves Palmdale, America gets a new, safer, improved Shuttle
           orbiter: one that is revitalized, more operationally fit and outfitted with the latest technologies," said
           Rick Stephens, Boeing RSS vice president and general manager.

           Shuttle orbiter major modifications (OMMs) are typically performed on each vehicle approximately
           every three years. The work is being conducted for Shuttle prime contractor United Space
           Alliance. Contract value is not yet final.

           Stephens said astronaut safety is paramount to the Palmdale workforce. "Every employee in
           Palmdale understands the importance of the work they do," he said. "They know their ultimate
           customers are the men and women who fly these incredible spacecraft. And they take personal
           accountability for ensuring their safety though quality workmanship. Our record in that regard has
           been consistently impressive. Nevertheless, we remain obsessed with continuous improvement to
           do our work safely, faster, better and cheaper." Stephens said an expanded training regimen is
           being adopted for work on Columbia and all subsequent vehicle modifications. Included are
           awareness training, videos, an enhanced orbiter entry/access class, computer-based training and
           orbiter orientation training. In addition, each employee is required to complete a detailed
           certification procedure.

           The highlight of this OMM will be installation of a $9 million "glass cockpit" called the Multifunction
           Electronic Display Subsystem (MEDS), the second such fleet installation following a similar effort
           on Atlantis last year. Technicians will replace Columbia's four existing cathode-ray tube screens
           and numerous mechanical gauges and instruments with nine full-color, flat-panel displays. This will
           allow Shuttle crews to operate with the convenience and control of the most advanced commercial
           and military flat-panel display technology available today.

           Developed by Honeywell Space Systems, Phoenix, Ariz., MEDS is a space-qualified adaptation of
           the display technology used on the Boeing 777. It will provide Shuttle crews with easy access to
           vital information through the two- and three-dimensional color graphic and video capabilities of its
           onboard information management system. Information will be interchangeable between screens,
           allowing crews to select the display format that best suits the needs of their particular mission.

           MEDS eliminates obsolescence concerns and is less expensive to maintain than present
           electro-mechanical devices. Besides reducing maintenance costs, MEDS will reduce vehicle weight
           and power consumption, improve Shuttle reliability and performance and improve Shuttle safety by
           simplifying cockpit panels and providing a redundant display capability. MEDS is also capable of
           future upgrades.

           Columbia also will be installed with a single Global Positioning System (GPS) satellite navigation
           receiver and prepared for future installation of a triply-redundant GPS system that may eventually
           replace the current system. GPS will provide more accurate and capable vehicle attitude and
           location data and reduce Shuttle program costs by eliminating ground stations.

           Several modifications to Columbia are designed to accommodate the possibility of supporting
           International Space Station (ISS) missions in the future. Included are electrical and structural
           provisions for modifying the orbiter's docking system, increased cooling and power capacities, a
           wireless video system that will support payload requirements for near-term ISS missions by
           documenting the assembly process, and upgrades to the ship's UHF space communications system.
           Columbia will retain its internal airlock.

           Operational enhancements include increasing Columbia's load-carrying capability; upgrades to
           thermal protection system tiles and blankets; orbital maneuvering system/reaction control system
           thruster performance improvements; and a series of measures to reduce the orbiter's weight. Most
           notable among the weight savings will be the removal of approximately 1,000 pounds of
           development flight instrumentation wiring unique to Columbia that was used during the fleet's first
           flights to monitor Shuttle performance. Safety and reliability enhancements include provisions to
           protect the orbiter's cooling system and the leading edges of the wings from space debris, a partial
           structural fortification of the crew module floor to increase the crew's probability of surviving a hard
           landing and enhancements to the vehicle's hydraulic system.

           During five months of structural inspection, technicians will scour Columbia using the latest
           technologies to search for possible fatigue, corrosion, or broken rivets or welds.

           In support of ongoing USA and NASA fleet inspections, an extensive inspection of Columbia's
           electrical wiring system will be performed. All accessible wiring harnesses will be inspected and
           abrasion protection applied to any area where wires/harnesses could, or do, contact any screw
           head/tail, rivet tail or other sharp or protruding metal edges. In addition, selected harnesses
           enclosed in convoluted tubing will be removed, disassembled, evaluated, reassembled and
           reinstalled to validate the NASA inspection criteria currently being used on Shuttles Discovery and
           Endeavour. Tests will be conducted to confirm resistance to damage, vibration, shorting and
           age-related degradation.

           Boeing Palmdale personnel also will perform preflight vehicle checkouts, significantly reducing the
           time required to process Columbia for her next flight.