1、 Public Lessons Learned Entry: 3101Lesson Info:a71 Lesson Number: 3101a71 Lesson Date: 2010-06-8a71 Submitting Organization: KSCa71 Submitted by: Annette PittSubject: Orbiter Spotting Laser System Abstract: Properly “spotting,” or accurately positioning, the Space Shuttle orbiter in the Orbiter Proc
2、essing Facility (OPF) on the first roll-in attempt rarely occurred before the orbiter laser spotting system was put into use. The cost associated with delays was significant because employees had to wait for the spotting operation to be completed before they could begin work. In addition to the cost
3、 savings, a timely “spot” protected the orbiter and Shuttle workers from the elements when inclement weather approached the OPF. This lesson describes the orbiter spotting system and the guidelines followed to use it successfully.Description of Driving Event: Properly spotting the orbiter in the OPF
4、 was critical to avoid damage when the platform extensions used in the overall processing of the launch vehicle were extended next to it. An accurate placement on the first roll-in attempt rarely occurred until the orbiter laser spotting system was put into use, and the cost associated with delays w
5、as significant because of the number of employees who had to wait for the spotting operation to be completed before they could begin work. In addition to the cost savings, a timely “spot” protected the orbiter and Shuttle workers from the elements when inclement weather approached the OPF. The orbit
6、er laser spotting system consists of two lasers (theodolites), each mounted on a tripod, and a tug target. One laser is “bucked in” (i.e., made parallel to the reference points) over the orbiters nose landing gear (NLG) centerline and aimed at the tug target, while the other is bucked in over the ri
7、ght main landing gear (RMLG) centerline and aimed at the RMLG strut. The tug target is a rectangular aluminum box with a translucent front panel containing a series of vertical lines evenly spaced across the front panel with the centerline in the center of the tug. The target allows the tug operator
8、 to maintain a particular course by keeping the NLG laser beam on a given vertical line as determined by the move director. As the orbiter is towed, the move director monitors the laser on the RMLG and adjusts the operation of the tug accordingly.Lesson(s) Learned: The orbiter laser spotting system
9、became a very useful visual aid to spotting, although using it still relied on the experience and skill of its operators. The following guidelines were key to making it successful: 1. Determine the amount of correction needed by towing a short distance with the laser on the tug target centerline. 2.
10、 Apply the correction determined necessary and follow this new reference line on the target. Continue on a straight line using this new reference line without correcting for the NLG. 3. Upon reaching the forward jacks with the tug, make sure the RMLG laser is clearly within tolerance. If not, back o
11、ut the orbiter completely and retry the spotting operation. 4. Once the tug clears the floor jacks, make the correction(s) needed to spot the NLG. The main landing gear (MLG) should remain within tolerance even with a significant NLG correction because of the short distance required to spot the NLG.
12、 Recommendation(s): Lasers and targets can be very useful in work that involves aligning, leveling, measuring.Evidence of Recurrence Control Effectiveness: Spotting successfully on the first attempt became routine.Provided by IHSNot for ResaleNo reproduction or networking permitted without license f
13、rom IHS-,-,-Documents Related to Lesson: Orbiter Towing and Spotting presentation Click here to download communication document. Mission Directorate(s): a71 Space OperationsAdditional Key Phrase(s): a71 1.Ground support systemsa71 1.Human factors planningAdditional Info: a71 Project: Space Shuttle ProgramApproval Info: a71 Approval Date: 2010-08-26a71 Approval Name: mbella71 Approval Organization: HQProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
