1、Lessons Learned Entry: 1479Lesson Info:a71 Lesson Number: 1479a71 Lesson Date: 2004-04-02a71 Submitting Organization: GSFCa71 Submitted by: Scott GlubkeSubject: Lessons Learned from SNOE Reentry Abstract: The Student Nitric Oxide Explorer (SNOE) spacecraft and its instruments were designed and built
2、 at the Laboratory for Atmospheric and Space Physics (LASP) of the University of Colorado. SNOE was a small scientific satellite that measured the effects of energy from the sun and from the magnetosphere on the density of nitric oxide in the Earths upper atmosphere. The SNOE was launched on Februar
3、y 27, 1998 and reentered on December 13, 2003 at 09:34 GMT. This document summarizes the lessons learned for the reentry of the SNOE. Even though SNOE was a small spacecraft that had little possibility of impacting the earth, it was an excellent opportunity for SSMO to work through our perceived ree
4、ntry process. These lessons learned will help to clarify the activities during the reentry of any other NASA mission. Also, recommendations for changes to the NASA Policy Directive (NPD 8710.3A), NASA Policy for Limiting Orbital Debris Generation, will also be suggested. Predicting reentry dates is
5、an important task for NASA to maintain public safety. Despite any minimal probability for debris impacting, the mission specific program/project must be aware of all reentry related information including launch vehicles and upper stages. Summary of Lessons Learned: Description of Driving Event: Reen
6、try of spacecraft into earths atmosphere at end of life.Lesson(s) Learned: All of the lessons learned form the SNOE reentry are summarized below and are discussed in detail Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-in the following section. 1.
7、”Maintenance” of reentry information is not defined in the current version of NPD 8710.3A. Updates to the reentry information are done more on a “calendar” basis instead of a “relative reentry” basis.2. The “coordination” of reentry information within the agency and “notification to appropriate pers
8、onnel” is ambiguous within the NPD.3. The “mission specific program/project“ is responsible for implementing the orbital debris mitigation measures and guidelines. To be able to do this effectively the program needs to understand the orbit and reentry characteristics for each mission, and the daily
9、operations and orbit determination activities are an essential input to the reentry predictions. The orbit determination activities are also necessary to plan the daily operational passes. Any “program specific“ predictions must be coordinated with Code Q (OSMA).4. CMOC routinely provides standard o
10、rbit data (TLE, etc) to GSFC OIG web site and to JSC. All NASA related reentry information is normally distributed to JSC. Any request for “special data” needs to be coordinated with CMOC and JSC so as not to cause confusion with the standard data processing.Recommendation(s): There are three areas
11、that should be addressed in the NPD. The fourth recommendation is for GSFC information and does not impact the NPD and is not discussed here. First, a better definition of what is required to “maintain” the reentry information should be developed. Several different viewpoints exist as to how often t
12、he predictions should be updated. GSFC has developed a set of revised guidelines that should be incorporated into the NPD or used as a starting point for further discussion. Secondly, clarification of who is “appropriate personnel” is required. There were several instances during the SNOE reentry wh
13、ere some people had received updated information while others had not. A clear distribution list of “appropriate” offices should be defined. Finally, the “mission specific program/project” has a definite responsibility and participation in the reentry activities. The program office (SSMO) must be ab
14、le to effectively manage the daily operations and the EOM plan. Consistent and timely updates to the reentry predictions are necessary for budget and manpower planning. Any mission specific reentry predictions must be coordinated with Code Q. At some point the mission specific predictions should tra
15、nsition to the CMOC predictions via the ODPO. A possible transition point could be reentry minus 30 days. Evidence of Recurrence Control Effectiveness: N/AProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Documents Related to Lesson: NPD 8710.3A, NASA
16、Policy for Limiting Orbital Debris GenerationMission Directorate(s): a71 ScienceAdditional Key Phrase(s): a71 Disposala71 Flight Operationsa71 Policy & Planninga71 Safety & Mission Assurancea71 SpacecraftAdditional Info: Approval Info: a71 Approval Date: 2004-06-18a71 Approval Name: Al Galloa71 Approval Organization: GSFCa71 Approval Phone Number: 301-286-3756Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
