110 likes | 257 Views
GPS Operations CGSIC Brief 21 September 09 Lt Daniel Boyd 2d Space Operations Squadron This briefing is UNCLASSIFIED. Overview. Navigation and Timing Performance Navigation Performance Time Transfer Performance Constellation Status. UTC TIME TRANSFER Specification 28ns.
E N D
GPS Operations CGSIC Brief 21 September 09 Lt Daniel Boyd 2d Space Operations Squadron This briefing is UNCLASSIFIED UNCLASSIFIED
Overview • Navigation and Timing Performance • Navigation Performance • Time Transfer Performance • Constellation Status UNCLASSIFIED
UTC TIME TRANSFERSpecification 28ns UNCLASSIFIED
GPS Space Status – 03 Aug 2009 Nav/Bus /Clock/Reaction Wheel Performance Status SV (PRN) Clock* Wheel KEY * II/IIA = Rb, Rb, Cs, Cs IIR = Rb, Rb, Rb Clock/Wheel Key Meets Spec Reduced Capability Unusable for Ops Unused In Use Unhealthy Bus/Nav Key Full Redundancy Redundancy Lost Reliability Unknown Drifting within Plane 5
Constellation Status Summary Total SVs in Category Changes Since Last Update • 21 (+1) SVs past design life (including residual SVs) • 18 (+0) Operational SVs past design life • 15 (+0) SVs past pre-launch mean life estimate (MLE) (including residual SVs) • 12 (+0) Operation SVs past pre-launch mean life estimate (MLE) • 19 (+0) SVs one component away from Nav mission failure (including residual SVs) • 16 (+0) Operation SVs one component away from Nav mission failure • 8 (+0) SVs one component away from bus failure (including residual SVs) • 6 (+0) Operational SVs one component away from bus failure 6
IIA Vehicles On Last Clock • SVN 36: has a higher likelihood of failing due to its Rb clock being turned on • with over 8 years of on-orbit storage • SVN-37: being stored as on-orbit spare in LADO • SVN-32: being stored as on-orbit spare in LADO • SVN-35: being stored as on-orbit spare in LADO Bottom Line: 11 of 15 IIAs left are on their last clock
IIR/IIR(M) Clock Status • No IIR/IIR(M) clock failures to date • SVN 43: • First IIR launch, AFS 3 on for test purposes only • SVN 44: • AFS 1 had a baseplate heater failure • Clock is assessed as viable • Performance could be slightly degraded during eclipse season • SVN 61: • AFS 3 clock failure • Switched to AFS 1
25 GPS Locations 180 57 43 F3 C1 23 50 55 37 160 58 B4 51 E1 35 B5 140 30 36 39 B2 D2 46 26 B6 120 A1 33 C2 IIF-1 C3 59 49 E6 100 GLAN (deg) F2 B1 56 40 E3 52 A2 80 34 D4 60 Watch List 53 61 D1 41 F1 C4 54 E4 Empty Slot 40 32 44 B3 E2 24 47 Block IIA 20 48 A4 45 Block IIA residual D3 38 27 0 Block IIR A3 F4 60 Block IIR-M A B C D E F Block IIR-M (L-5) SVN-26 Rephase Complete: Sept ‘09 9
160 100 OPSCAP 120 140 FMC PMC NMC Inactive Maneuver 60 40 BlockSVNs ( # ) IIA 22-40 (14) IIR/IIR-M 41-61 (18) Current IIR-M’s (48, 52, 53, 55, 57, 58) 20 180 0 F3 57 C1 Geographic Longitude of Ascending Node (GLAN) 23 43 B4 58 E1 37 51 35 A1 30 39 B2 36 D2 46 C2 33 26 C3 59 55 F2 E3 B1 40 56 80 A2 52 34 D4 NOTE: Chart reflects status of bus & navigation payload only (not NDS payload status). D1 F1 61 C4 E4 53 41 54 32 B3 E2 44 24 47 25 A4 D3 48 45 27 A3 38 F4 60 F B C D E A
Summary • Navigation and Timing Performance • Navigation Performance • Time Transfer Performance • Constellation Status • Questions… UNCLASSIFIED