What NASA will learn from dissecting Atlantis, Discovery, and Endeavour
- By Greg Freiherr
- Air & Space magazine, May 2012
(Page 2 of 4)
Orbiter Processing Facility 2 is all about warnings. The blue metal door leading inside bears two against unauthorized entry, a third about electrical hazards, and a caution against unfastened objects.
Once inside today, the orbiter processing team will remove one of Endeavour’s two orbital maneuvering system pods, which bookend the vertical stabilizer. As the drone of ventilators fills the building, a technician wearing a “Lucky’s Bar” T-shirt thumbs a manual detailing the steps for excising the orbital maneuvering systems. Held by a latticework of steel beams, the pod rotates out and into the free-hang position, ready for the next day’s crew to winch it into retirement.
Long gone are Endeavour’s main engines. Technicians have plucked them with what looks like a Space Age version of a medieval battering ram. Mounted on a 20-foot-high forklift, the steel probe, its tip sheathed in black padding, had pressed into the nozzle of each engine. It extracted them one at a time, hauling them away for storage in a NASA facility at White Sands, New Mexico. If Endeavour’s engines fly again, it will be on NASA’s new Space Launch System, a Saturn V lookalike now in the planning stages.
The shuttle’s emergency crew escape system featured an extending pole; these will be collected from all three orbiters. “That’s a safety reason” for the collection, says Stephanie Stilson, orbiter transition and retirement flow director. “You have some energy built up in that system, where you could potentially hurt someone” if the pole were left intact.
The airlocks and docking rings through which crews on Endeavour and Atlantis entered the International Space Station will be gathered and stored for possible later use. (Discovery’s airlock and docking ring will remain in place.) And technicians have pulled the robotic arms from all three orbiters. Atlantis’ arm will remain with NASA, while Endeavour’s will be returned to the Canadian Space Agency, which developed the technology. Discovery’s robotic arm will go on exhibit at the Steven F. Udvar-Hazy Center.
Discovery returned from its last mission in March 2011, and just weeks later, crews took out the forward reaction control system. The forensic rhinoplasty began with members of the orbiter processing team fanning out across Discovery’s nose while a winch operator levitated the control system slowly up and away from the shuttle. The thruster assembly, bolted into a steel-beam frame, was placed on a trailer, where technicians scrubbed the forward reaction control system of its toxic fuels and oxidizers before reinserting it into the orbiter. In the aft end of the spacecraft, the holes once filled by Discovery’s main engines will be filled with replica engines built from test components. Any additional cavities created by the removal of orbiter components will be covered by panels to make their absence impossible to detect from the outside.
Four months after NASA ferries Discovery atop a modified Boeing 747 to Dulles International Airport (near the Udvar-Hazy Center), Endeavour is scheduled to move to the California Science Center in Los Angeles. And in February 2013, Atlantis will be rolling toward the visitor’s center at Kennedy Space Center in Florida.
The main reason for examining orbiter pieces left behind—wires, feed lines, tanks, valves, and electronics—is to avoid future failures, says John Shannon, NASA shuttle program manager. NASA engineers already have some ideas about what to look for. During the ascent of Columbia on mission STS-93 in July 1999, an electrical short knocked out the computer-based controllers for two of the three main engines. When the engines switched automatically to backup controllers, the mission was saved. It was later determined that mishandling of a wire damaged its insulation. Vibration during repeated launches had caused further wear until an exposed conductor touched a screw, the contact shorting the controllers five seconds after liftoff.