Bruce Buckingham
  407/867-2468                                    April 20, 1990

  KSC RELEASE NO. 74 - 90

  GIANT CRAWLER TRANSPORTER TO PASS 1000 MILES ON STS-35 ROLLOUT

       Kennedy Space Center's Crawler Transporter No. 2 could
  qualify for a Florida antique automobile tag. But the 25-year-
  old, 3,000 ton vehicle will just be passing its first 1,000 mile
  landmark as it carries the Space Shuttle Columbia to Pad 39-A for
  launch on the STS-35 mission in May.

       A ceremony marking this historic event is scheduled to be
  held during the STS-35 rollout on Sunday, April 22. KSC managers
  and those playing a role in the transporter's creation and
  operation over the years will be gathered approximately .8 of a
  mile to the east of the Vehicle Assembly Building as the
  transporter moves slowly past the point on the turnpike-wide
  crawlerway marking the 1,000th mile of service.

       The twin crawler transporters are vital links in the launch
  processing chain. They provide the means by which the launch
  vehicle atop its massive mobile launch platform is transferred
  from the Vehicle Assembly Building to the launch pad.

       During its slow roll to reach the 1,000 mile marker,
  transporter 2 has been operated by 10 different drivers. It has
  supported  Apollo, Skylab and Space Shuttle missions and provided
  service to the nation's space effort in the four decades from the
  1960s into the 1990s.  Crawler Transporter No. 1 is not far
  behind in accumulated mileage; it lacks approximately 25 miles to
  reach the 1,000-mile mark.

       Early concepts of transporting launch vehicles to the pads
  included a barge and canal system, a rail system, and the land
  transporter. The task of transforming one of these concepts into
  reality fell to Donald D. Buchanan, then Chief of the Launcher
  Systems and Umbilical Tower Design Section.  Now retired,
  Buchanan lives within sight of KSC at nearby Titusville.

       "The crawler transporter was the dark horse of the concepts
  being considered," Buchanan said. "But eventually the barge/canal
  concept proved too unstable and the rail system more costly and
  inflexible due to the loads it would be required to carry."

       Following a year of study, NASA decided in 1962 that the
  cross-land tracked vehicle, or crawler transporter, would be the
  most feasible means of moving the launch vehicle to the pads. An
  ambitious task was ahead.  Large volumes of soggy land had to be
  moved and a heavy-duty crawlerway built. The goal: build a system
  capable of moving the largest structures ever to be moved on land
  and move them several miles in a reasonable amount of time.

       "At the time," Buchanan said, "no one dreamed something that
  moved so slow would ever reach 1,000 miles."

       In 1963 the Marion Power Shovel Company, Marion, Ohio, was
  awarded the contract to build two crawler transporters. When
  built, the transporters dwarfed the self-propelled, strip-mining
  shovels after which they were patterned. The transporters were
  assembled in 1965-66. The cost of both transporters was under $15
  million.

       In 1969, the crawler transporters won the Great Britain
  Royal Automobile Club's third Diamond Jubilee Trophy Award. This
  placed the transporters in a class with the antarctic
  transporters and the hovercraft. Then President of the Royal
  Automobile Club, Lord Mountbatten, gave the award to NASA.
  Buchanan received the award for NASA for "the design, development
  and construction of the crawler transporter which provides
  mobility to the space vehicle structures required by the
  Apollo/lunar landing program at Kennedy Space Center, Fla."

       As the largest land vehicles ever built, the transporters in
  1977 were designated as National Historic Mechanical Engineering
  Landmarks by the American Society of Mechanical Engineers.

       Later in 1977, extensive modifications were made to the
  transporters. Modifications include the installation of a new
  central control room and the addition of a programmable
  controller capable of rapid trouble-shooting if a problem occurs
  during a critical move.  Also, a laser docking system was
  installed which allows the driver of the transporter to dock the
  massive vehicle with an accuracy of plus or minus one inch.

       Included in the modifications on transporter 2 was the
  installation of a new odometer. A plaque certifying the
  previously logged miles was placed in the transporter's cab. With
  the miles transporter 2 logged during the Apollo/Saturn V years
  added to the miles it has logged during the Shuttle program, the
  total will reach 1,000 during the STS-35 rollout. Pre-
  modification mileage totaled 644.

       The heaviest load transporter 2 has carried was the Saturn
  1B/Skylab on its mobile launcher platform. The combined weight of
  the platform, launch vehicle and payload totaled 13.2 million
  pounds, more than twice the weight of the transporter itself.

       Each transporter weighs six million pounds. The flat, load-
  toting tops are 131 feet long and 114 wide, about the size of a
  baseball diamond. The height of the top is adjustable by
  hydraulic jacks, from 20 feet to 26 feet.  The mobile launcher
  platforms stand on six massive stanchions at their VAB and pad
  locations.  The jack mechanism raises and lowers the platforms
  onto the stanchions at the beginning and end of a move.

       Two 2,750 horsepower diesel engines provide main propulsion
  power to drive four 1,000 kilowatt generators. Additionally, two
  1,065 horsepower diesel engines drive two 750 kilowatt generators
  providing power to the leveling, jacking, steering, lighting, and
  other onboard equipment systems. Also, there are 16 traction
  motors, four on each truck, rated at either 187 or 375 horsepower
  each. The transporter carries 5,000 gallons of diesel fuel on
  board and burns about 160 gallons per mile.

       The top speed of the transporter unloaded is two miles per
  hour. Moving a Space Shuttle to the pad, it averages less than
  one mile an hour.

       The transporter moves on four double-tracked trucks. Each
  truck is 10 feet high and 40 feet long. A single shoe on the
  track belt weighs 2,000 pounds each. There are 57 shoes per belt,
  and eight belts per transporter.

       The transporter has a turning radius of 500 feet. During the
  slow move up the launch pad's five percent grade, the
  transporter's leveling system does not allow the tip of the Space
  Shuttle's external tank to vary more from the vertical than the
  diameter of a basketball.

       The 130 foot-wide crawlerway was initially constructed by
  the Army Corp of Engineers with an asphalt top surface. However,
  due to the weight of the transporters and the space vehicles it
  carried, the road way was soon torn-up and had to be replaced
  with a more durable surface. Other surfaces tested included sand
  and gravel. Studies eventually proved a smooth river rock would
  give the transporter the traction it needed to round the curves
  without marring or sticking to the shoes.

       The crawlerway is now built in three layers with an average
  depth of seven feet. The thickness of the gravel top surface is
  eight inches on the curves and four inches on the straightaways

       The crawlers are expected to continue their traditions of
  service well into the next century.

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  NOTICE TO EDITORS:  The STS-35 rollout is scheduled to begin at 8
  a.m. EDT on Sunday, April 22.  KSC gates will be open to
  accredited news media covering rollout beginning at 5:30 a.m.
  Those who plan to cover only the ceremony should be at the KSC
  News Center no later than 8:30 a.m.