1、Public Lessons Learned Entry: 3656 Lesson Info: Lesson Number: 3656 Lesson Date: 2010-08-3 Submitting Organization: KSC Submitted by: Annette Pitt Subject: Accurate As-Built Drawings Abstract: The booms and joints of the Remote Manipulator System (RMS) are covered with thermal blankets to help prote
2、ct the electronics and joint components on orbit. These blankets are attached with Velcro and are grounded to the RMS by ground wires. Instead of as-built drawings for the RMS thermal blanket system, the vendor provided a template, which could be used to create additional templates for all other bla
3、nkets. Cartoon drawings identified where to connect the Velcro and ground wires. The vendor outsourced the blanket manufacturing and repair to a subcontractor who in turn used these inaccurate cartoon drawings to manufacture and repair the thermal blankets. We often found blankets that do not fit co
4、rrectly because of incorrect Velcro placement and ground wire locations. Such blankets are unusable. When the Orbiter Boom Sensor System (OBSS)/Inspection Boom Assembly (IBA) came online after return to flight following the Columbia accident, the vendor started providing as-built drawings with dimen
5、sions as requested. Description of Driving Event: The vendor was required to provide replacements for aged RMS blankets. The vendor outsourced the manufacturing and provided the subcontractor with only cartoon drawings for production. Many of the replacement blankets were not usable because attachme
6、nt points for Velcro and ground wires were mislocated. The vendor never provided the templates needed for manufacturing. KSC Engineering had to initiate Problem Reports so the blankets could be adjusted for use on the RMS. Provided by IHSNot for ResaleNo reproduction or networking permitted without
7、license from IHS-,-,-Figure 1: Cartoon of CCTV Bracket without dimensions or tolerances Lesson(s) Learned: Accurate drawings are essential for ensuring the fit, form, and function of the thermal blankets on the RMS. Manufacturing from inaccurate Provided by IHSNot for ResaleNo reproduction or networ
8、king permitted without license from IHS-,-,-drawings caused a shortage of thermal blankets and forced KSC Engineering to repair old blankets and have them approved by a material review board instead of using the new blankets. Recommendation(s): Drawings provided by vendors and manufacturers should b
9、e as accurate as possible and include adequate pictures of the hardware. Drawings should be dimensioned. Sketches are rarely acceptable. When the IBA was delivered to KSC, accurately dimensioned drawings for the RMS Thermal Blanket System were provided, which alleviated many ongoing problems. Eviden
10、ce of Recurrence Control Effectiveness: N/A Documents Related to Lesson: N/A Mission Directorate(s): Space Operations Additional Key Phrase(s): Ground processing and manifesting Configuration Management Entry Systems Engineering design and project processes and standards International partner coordination Acquisition / procurement strategy and planning Additional Info: Project: Space Shuttle Program Approval Info: Approval Date: 2011-03-01 Approval Name: mbell Approval Organization: HQ Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
