1、Lessons Learned Entry: 1005Lesson Info:a71 Lesson Number: 1005a71 Lesson Date: 1997-02-01a71 Submitting Organization: HQa71 Submitted by: David M. LengyelSubject: Space Shuttle Program/Block II Space Shuttle Main Engine (SSME)/Test Schedule Description of Driving Event: Block II SSME Test Schedule S
2、lippage and SSME Test Stand AvailabilityLesson(s) Learned: The schedule for the first flight of the Block II engine has slipped, from September 1997 to December 1997. This schedule is optimistic and contains no slack for future development problems. The schedule also requires continued availability
3、of three test stands at the Stennis Space Center (SSC).Recommendation(s): Maintain the full scope of the planned test programs. Assure the availability of test stand A-2 at SSC for as long as it is needed for the Block II engine test programs so that three test stands continue to be available.Eviden
4、ce of Recurrence Control Effectiveness: The development and certification test programs will be maintained as originally planned. Test stand availability has been coordinated with other program test requirements to support completion of Block II HPFTP certification testing in February 1998. Three te
5、st stands are required only until July 1997 to support this schedule. A mid-May milestone to initiate construction authorization for the July reconfiguration of Test Stand A-1 for X-33 testing will be reassessed based on fuel pump development status at that time. The other two test stands will remai
6、n dedicated to SSME testing. After test stand modification, conversion back to SSME test configuration would take approximately 1 month. The first flight of the Block II configuration has been reassigned to STS-91, currently Provided by IHSNot for ResaleNo reproduction or networking permitted withou
7、t license from IHS-,-,-scheduled for May 1998.Due to the development problems with the ATP HPFTP and the associated schedule slips, the SSP has elected to certify an interim Block II configuration, designated Block IIA. Block IIA will consist of Rocketdynes current HPFTP in conjunction with the othe
8、r Block II components and will provide the safety and reliability benefits of the large throat main combustion chamber at the earliest opportunity. This configuration will be certified to fly nominal missions at 104% to 104.5% rated power level (RPL) and will maintain the current 109% RPL contingenc
9、y abort capability.Documents Related to Lesson: N/AMission Directorate(s): a71 Space Operationsa71 Exploration SystemsAdditional Key Phrase(s): a71 Aerospace Safety Advisory Panela71 Policy & Planninga71 Test Facilitya71 Test & VerificationAdditional Info: Approval Info: a71 Approval Date: 2001-11-01a71 Approval Name: Bill Loewya71 Approval Organization: QSa71 Approval Phone Number: 202-358-0528Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
