REG NASA-LLIS-5200-2012 Lessons Learned - Vehicle versus Ground Synchronization.pdf

1、Public Lessons Learned Entry: 5200 Lesson Info: Lesson Number: 5200 Submitting Organization: KSC Submitted by: Jenni Palmer Subject: Vehicle versus Ground Synchronization Abstract: During the Constellation Program, rework caused excessive costs and schedule slip. The rework resulted from a lack of c

2、oordination in the design and development of flight hardware and ground support equipment. Synchronization of design engineering activities and baseline documentation would address this problem, and should be performed as a fundamental systems engineering best practice. Description of Driving Event:

3、 The Constellation Program had a very aggressive development schedule, using a fast-track method. The vehicle design for the Ares I was being developed at the same time as the ground support equipment (GSE). Changes to the vehicle design were being made frequently. Because there was a program-to-pro

4、ject acceptance delay (needed for communication back and forth across Centers for approval and then on to the Program office), it took a long time for the changes to be added to the program baseline. During that time, the Mobile Launcher Team was working on an older configuration while the flight ha

5、rdware designers were working to the latest updates. The result was unnecessary and costly redesign and rework by Ground Operations projects. For example: (1) The distance from the launch tower to the vehicle was uncertain. If the distance between the tower and the launch vehicle was too close, ther

6、e would be a greater chance that the launch vehicle would hit the tower during liftoff. (2) Uncertainty in the areas where access needed to be provided to the flight vehicle resulted in the use of flexible stairs. (Permanent stairs would be designed at a later date.) This produced a less-than-desira

7、ble design for the stairs, involving multiple transitions to reach the platform level. Lesson(s) Learned: The baseline design configuration for the vehicle should be stabilized before Ground Operations projects, such as the Mobile Launcher and associated GSE, are developed. As the vehicle is being d

8、eveloped, prior to Critical Design Review (CDR), design issues can be resolved early by integrating key people from the Ground Systems team on the Flight Systems Integrated Product Team (IPT). Fabrication of ground systems should not be initiated until a functional vehicle has been baselined and tes

9、ting has been done to reach a 95% confidence level in the design. Portions of the design that show a low risk of rework can proceed to fabrication. However, portions of the design that show a high risk of rework should not proceed to fabrication until the risk of rework is reduced. Recommendation(s)

10、: Although development of flight systems should take precedence, ensure that ground systems and vehicle development teams continuously share design input (i.e., real-time collaborative CAD models) with each other. One effective method to accommodate KSC ground processing requirements in the design o

11、f the integrated flight hardware (JSC/MSFC) and ground hardware (KSC) is through remote collaborative real-time combined CAD/JACK/DELMIA modeling, such as the work done by the KSC Human Engineering Modeling and Performance (HEMAP) lab. If a staggered serial approach for development is taken, ensure

12、that a stable configuration is available before the CDR. Allow portions of the design that show low risk of rework to proceed to fabrication. But do not allow portions of the design that show a high risk of rework to proceed to fabrication until the risk of rework is reduced. As the vehicle is being

13、 developed (prior to CDR), integrate key people from the Ground Systems team into the Flight Systems IPT in order to flag potential problems. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Evidence of Recurrence Control Effectiveness: N/A Documents

14、Related to Lesson: N/A Mission Directorate(s): Exploration Systems Additional Key Phrase(s): Program Management. Program Management.Program planning, development, and management Additional Info: Project: Constellation Approval Info: Approval Date: 2012-05-08 Approval Name: mbell Approval Organization: HQ Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-