1、Lessons Learned Entry: 1194Lesson Info:a71 Lesson Number: 1194a71 Lesson Date: 2001-07-23a71 Submitting Organization: GSFCa71 Submitted by: R.J. McGlynnSubject: Understanding Lightning Protection Policies during ELV Launch Operations Description of Driving Event: Several days prior to the launch of
2、the GOES-M/Atlas II mission in July of 2001 a discontinuity was identified regarding what the spacecraft response would be to specific lightning protection phase announcements as compared to the launch vehicle response during launch countdown operations. A potential for a launch countdown scrub exis
3、ted which was not fully understood by the community until very late in the processing flow.Lesson(s) Learned: The GOES spacecraft had established a policy whereby if lightning was within 5 nautical miles of the pad and the spacecraft had not yet powered up, power up would be delayed until the adviso
4、ry cleared. If the spacecraft was powered at the time of the lightening advisory, the spacecraft would be powered down. When the advisory was lifted the spacecraft would have to go through another power-up cycle and engineering assessment prior to verifying a “go for launch“ condition. Depending on
5、where this event occurred, the GOES launch window of approximately 1 hour was marginally acceptable for maintaining an ability for a same day launch attempt. The Atlas vehicle, on the other hand, maintains its powered/unpowered state so as to minimize electrical potential differences in the presence
6、 of the lightening condition. The GOES policy was cause for significant concern amongst the launch vehicle community, and this concern amplified because the policy was not fully understood by all parties until just days before the scheduled launch ( July, a month with significant lightening potentia
7、l at the Cape).Recommendation(s): Spacecraft processing lightning policies should be addressed as a specific agenda item during early Ground Operations Working Group Meetings. The spacecraft and launch vehicle community should Provided by IHSNot for ResaleNo reproduction or networking permitted with
8、out license from IHS-,-,-clearly define their plans and expectations for not only launch countdown operations, but for all PPF and Pad operations as well. An early exchange of information may identify technical drivers, which may ultimately influence the policy, and guarantees that the community is
9、fully aware of possible operational impacts.Evidence of Recurrence Control Effectiveness: N/ADocuments Related to Lesson: N/AMission Directorate(s): a71 ScienceAdditional Key Phrase(s): a71 Flight Operationsa71 Ground Operationsa71 Launch Processa71 SpacecraftAdditional Info: Approval Info: a71 Approval Date: 2002-05-06a71 Approval Name: Jay Liebowitza71 Approval Organization: GSFCa71 Approval Phone Number: 301-286-4467Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
