|
||||
NASA studying potentially serious crawler problem BY WILLIAM HARWOOD STORY WRITTEN FOR CBS NEWS "SPACE PLACE" & USED WITH PERMISSION Posted: August 12, 2002
Each of the crawlers uses 16 massive 20-inch-wide JEL cylinders to lift a shuttle and its mobile launch platform and to keep the 12-million-pound load level while climbing the 5-degree incline to the surface of the shuttle's launch pad. Each JEL cylinder includes two large bearings, one at the top and one at the bottom. During recent work to refurbish two JEL cylinders on one of the crawlers, engineers were surprised to discover severely cracked bearings. Additional inspections were ordered and so far, nearly half of the bearings checked show signs of cracks. The concern is that an outright bearing failure on a fully loaded crawler would be extremely difficult to repair. It appears likely at least some of the bearing damage occurred years ago and it's possible the crawlers can safely operate "as is." An engineering analysis is underway. But sources say NASA does not have enough spare parts to immediately replace all of the cracked bearings if repairs ultimately are ordered. In that case, the shuttle program almost certainly would face a launch delay. But the full impact of such a worst-case scenario is not yet known and NASA managers are hopeful it won't come to that.
Each crawler features four "trucks," each one with two cleated belts made up of 57 "shoes" per belt. The shoes weigh one ton each. Each truck, in turn, is equipped with four traction motors. The JEL cylinders use hydraulic power, provided by eight pumps, to lift a shuttle and its 8.8-million-pound mobile launch platform for the trip form the VAB to the launch pad. The cylinders can be extended about six feet. |
Hubble Astronomy Now presents Hubble: the space telescope's view of the cosmos. A collection of the best images from the world’s premier space observatory. U.S. STORE U.K. & WORLDWIDE STORE Apollo 15 DVD - offer ends soon For a limited time only, preorder your Apollo 15 DVDs at a special discount price. Two- and six-disc editions of this unique DVD are coming soon. U.S. STORE U.K. & WORLDWIDE STORE |
||||||