Orbital Debris Assessment PDR ODA has been completed
Orbital Debris Assessment PDR ODA has been completed: • • • Forwarded to UCB, GSFC Explorers office, and to KSC. Following PDR, will work with UCB to remove TBD/TBRs Will work with GSFC/JSC to assess validity of approach and analyses ODA Guideline Compliance Status: • • • 3. 1 OPERATIONAL DEBRIS PASSING THROUGH LEO Guideline met: No debris released from pyrotechnic devices due to boots and restraints, vs a guideline of less than 1 mm (TBR). 3. 2 OPERATIONAL DEBRIS PASSING THROUGH GEO Guideline met: No debris released from pyrotechnic devices due to boots and restraints, vs a guideline of less than 5 cm (TBR). 4. 1 ACCIDENTAL EXPLOSIONS DURING MISSION Guideline met: Li-Ion Battery will have active charge control to prevent over charge Guideline met: Tanks are Inconel, designed to leak before burst at operational pressures 4. 2 ACCIDENTAL EXPLOSIONS AFTER COMPLETION OF MISSION OPERATIONS Guideline TBD: Plan for depleting Batteries is TBD Guideline met: Tanks will be completely emptied during depletion burn (no internal diaphragm) 4. 3, 4. 4, 4. 5 INTENTIONAL BREAKUPS Guideline met: All operations preclude intentional breakups. THEMIS MISSION PDR OVERVIEW-1 UCB, November, 2003
Orbital Debris Assessment ODA Guideline Compliance Status: • • • 5. 1 ASSESSMENT OF COLLISIONS WITH LARGE OBJECTS DURING MISSION OPERATIONS Guideline met: Total probability of any THEMIS probe having a collision with large objects is less than 9. 43 E-6, vs guideline of less than 0. 001. (for Probes only; Delta 3 rd stage and PC assessment to be performed by KSC) 5. 2 ASSESSMENT OF COLLISIONS WITH SMALL DEBRIS DURING MISSION OPERATIONS Guideline met: Probability of failure during the nominal 2 -year mission life of 0. 0015 vs guideline of less than 0. 01. 6. 1 DISPOSAL FOR FINAL MISSION ORBITS PASSING THROUGH LEO Guideline met: Probes in orbits P 1 and P 2 re-entering within 12 years with targeted depletion burns, and remaining Probes and Probe Carrier re-enter within 5 years with depletion burns. (From CSR) 6. 4 RELIABILITY OF POSTMISSION DISPOSAL OPERATIONS Guideline TBD: Reliability calculation is TBD 7. 1 LIMIT THE RISK OF HUMAN CASUALTY Guideline met: Each Probe casualty area is 2. 6768 m 2, vs guideline of less than 8 m 2. Guideline met: PC with 3 rd stage casualty area is 1. 0439 m 2, vs 8 m 2. Note: 7. 1 is per event – “An upper limit of 8 m 2 is derived by assuming an average risk of human casualty of 0. 0001 per reentry event. ” THEMIS MISSION PDR OVERVIEW-2 UCB, November, 2003
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