1、Public Lessons Learned Entry: 5003 Lesson Info: Lesson Number: 5003 Submitting Organization: KSC Submitted by: Jenni Palmer Subject: Combined First Stage Aft Skirt Umbilical Abstract: Combining the functions of two umbilicals into a single umbilical reduces risks at liftoff. Description of Driving E
2、vent: To meet requirements for clearance between the Ares I launch vehicle and the launch facility at liftoff, the design of the Ares I First Stage Aft Skirt Gaseous Nitrogen (GN2) umbilical was changed to a retractable flexhose design. The new flexhose design brought an increased risk for the umbil
3、ical to make recontact with the vehicle, which could be catastrophic. To decrease the risk of recontact, the GN2 and electrical umbilicals were combined into one. Lesson(s) Learned: Combining the GN2 umbilical and the electrical umbilical into a single flexhose eliminated an interface and reduced th
4、e risk of an umbilical making recontact with the vehicle. Recommendation(s): To reduce risk in future programs, combine functions into a single umbilical where possible. Evidence of Recurrence Control Effectiveness: N/A Documents Related to Lesson: N/A Mission Directorate(s): Exploration Systems Add
5、itional Key Phrase(s): Additional Categories.Spacecraft Additional Info: Project: Constellation Approval Info: Approval Date: 2011-10-03 Approval Name: mbell Approval Organization: HQ Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-