By Linda Herridge
NASA's John F. Kennedy Space Center
The crawler-transporter that will carry NASA’s Space Launch System (SLS) and Orion spacecraft to Launch Pad 39B for launch on Exploration Mission-1 in 2017 recently passed the first phase of an important milestone test at Kennedy Space Center in Florida.
The Ground Systems Development and Operations Program completed testing of the new traction roller bearings on crawler-transporter 2 (CT-2), on two of the massive vehicle’s truck sections, A and C, in late January. During the test, CT-2 was driven unloaded on crawlerway C, between the Vehicle Assembly Building and Ordnance Road.
As the crawler moved along, the left- and right-hand steering was tested in both directions. Workers performed visual inspections of the roller bearing pumps, valves and lines to ensure that the grease injectors worked properly and provided the required flow of grease to the new roller assemblies.
“The temperature of the roller assemblies were monitored and recorded using newly-installed thermocouples,” said Mike Forte, a senior project manager with QinetiQ on the Engineering Services Contract. “We were looking for any anomalies and establishing a baseline operating temperature for the new roller assemblies.”
Forte said temperature data on the surface of the roller assemblies also was collected using handheld infrared temperature monitoring devices. “We also closely monitored the system for any unanticipated vibrations or noise, which are indications of problems,” Forte added.
The test was a collaborative effort that involved about 30 NASA and contractor engineers and technicians from Kennedy and Ames Research Center in Moffett Field, Calif.
Upgrades to CT-2 include 88 new traction roller bearing assemblies, a modified lubrication delivery system, and a new temperature monitoring system that includes 352 new thermocouples.
Forte said subsequent tests will be used to establish permanent operational warning and shutdown limits for a fully-loaded crawler-transporter.
CT-2 returned to the VAB on Jan. 31 so work can continue to install new roller bearing assemblies on the B and D truck sections. Another test is scheduled for November, after installation of the second set of bearings has been completed.
Upgrades to CT-2 are necessary in order to increase the lifted-load capacity from 12 million to 18 million pounds to support the weight of the mobile launcher and future launch vehicles, including the SLS and Orion.