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X-ray Missions Delta: AXSIO Redux. Orbital Debris and End of Mission Plans Ivonne Rodriguez 30 April – 1 May, 2012. Subsystem Agenda. Micrometeoroid Damage Assessment Update Issues / Potential Risks / Future work Acronym List.
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X-ray Missions Delta:AXSIO Redux Orbital Debris and End of Mission Plans Ivonne Rodriguez 30 April – 1 May, 2012
Subsystem Agenda • Micrometeoroid Damage Assessment Update • Issues / Potential Risks / Future work • Acronym List
Micrometeoroid Damage Assessment Update: Structure and Components • Structure assessment • Damage is function of lifetime only. Structure is the same as in the previous AXSIO analysis. • Failure is defined as penetration of both facesheets. As a result, knowledge of maximum hole size is useful to put the damage in perspective. • Added maximum hole diameter (Not included in first AXSIO assessment). • Number of expected penetrations is reduced from 5 to 3. • Representative Components • Failure defined as penetration of surface. • Probability of tank damage is small because of structural shielding. Lifetime reduction does not reduce significantly the already low probability of damage. • In both analyses, the MEM 1c meteoroid environment model was used, to be consistent with the 2011 assessment.
Micrometeoroid Damage Assessment Update: FMA analysis • Analysis of particles striking the calorimeter from the FMA side: • FMA analysis not performed in 2011 analysis. • Assumed 3-mm glass window or filter in front of the detector. • Most particles reaching the calorimeter do not produce permanent damage to the instrument; damage is likely to be limited to temporary bright pixels and minimum cratering to the glass (micron size). • A particle of 0.05 cm is capable of penetrating the glass; however, the probability of that event is very low. • The Grun interplanetary flux model was used in this analysis be consistent with previous grating incidence analyses.
Issues / Potential Risks / Future work • The metering structure has a high probability of receiving about 3 penetrations by micrometeoroids during the 3 years of the mission. The predicted minimum hole diameter is approximately 0.47 cm. • A thicker structure would reduce the probability and number of penetrations. However, if the penetration ever occurs, the hole diameter would be larger (a bigger particle needed to perforate the structure). • Previous analysis predicted ≈ 5 penetrations for the same structure. • Slight improvement in probability of penetration for other components. • The analysis of the FMA predicts a high probability of < 3 particles reaching the detector from the telescope side. Because of the particle size, no permanent damage to the instrument is expected.
Acronym List • FMA – Flight Mirror Assembly • MEM – Micrometeoroid Engineering Model