Particles and Fields Package PFP PFDPU Peer Review

Particles and Fields Package (PFP) PFDPU Peer Review

Agenda PFDPU – Monday, May 9 Start Duratio n Who Content 10: 00 AM 0: 15 Gordon Introduction 10: 15 AM 0: 30 Gordon PFDPU Changes since PDR NOTE: Power Supply details (REG, IIB) are covered in a splinter session 10: 45 AM 0: 30 Donakowski PFDPU Mechanical 11: 15 AM 0: 30 Pankow Board Structural Analysis 11: 45 AM 0: 45 Gordon DCB 12: 30 PM 0: 30 Gordon Integration Status & Next Steps 2

PFDPU Driving Requirements (1) 3

PFDPU Driving Requirements (2) 4

PFDPU – Overall Block Diagram 5

PFDPU – Stacked Frame Structure (PFDPU view as of PDR) 6

PFDPU Mass Estimates • Last Year (just after PDR) • Current Estimates (ETU values measured for MAG and LPW) 7

PFDPU Power Estimates • Last Year (just after PDR) • Current Estimates and breakdown per board (ETU values measured for MAG and LPW) Only one REG or DCB powered on at any one time 8

PFDPU Changes since PDR • Subsystem specific changes to be discussed in those presentations • Significant PFDPU modification – Replacement of Hypertronics PC 104 stacking connector with a MDM based cable harness* • Minor PFDPU changes – Stacking order of REG and DCB – 16. 78 MHz clock (from DCB to DFB) sent via a dedicated shielded cable* – EUV Door Status signals routed to DCB * Planned, not yet implemented 9

PFDPU Backplane Modification • Hypertronics PC 104 Stacking Connector – ETU build revealed this use of the Hypertronics stacking connectors as a significant weak point of the MAVEN PFDPU • Connector Engagement issues • Pin Warping/Breakage – High probability of damage during mate/demate • Procurement problems – Lack of response to our technical concerns, long delays in quoting our orders, very long lead times, overall quality concerns • Blind Connection – difficult to verify engagement – Concerns expressed by all the MAVEN PFDPU Instrument teams • prompted us to look for alternative solutions 10

Various Hypertronics PC 104 connector hazards 11

MDM “Backplane” Use MDM connectors and cable harness: Well known and long established history in flight hardware o o No longer a “blind connection” Allows random access to PFDPU boards for during test and assembly o Standardize all PFDPU boards to MDM 37 Allows for common GSE equipment (breakout boxes) o o Common buys for ETU and Flight Bus Configuration is similar to PC 104 stackup: BUS 1 (P 1) - private DCB/REG (redundant) BUS 2 (P 2) - connects DCB/REG/IIB BUS 3 (P 1) - DCB/IIB/MAG/SEP/LPW (DCB connects directly to “in-board” instruments; redundant signals are combined on the Instrument boards, previously a function of the IIB) 12

MDM Harness Transition Plan • Retrofit the existing ETU boards – Remove PC 104 connectors and replace with “pigtailed” MDM 37 connection – If a relayout is planned between ETU and flight • PC 104 connector pads can be modified to optimize for wire connections • Connector change may free up some real estate – Removal of termination resistors for unused pins – Some boards require only one MDM 37 • Proceed with PFDPU integration using the harness • Use MDM 37 Breakout boxes for safe-to-mate and system debugging 13

Updated PFDPU Mechanical Design MDM connectors on top, with EMI shield Four skewers (two added to baseline design) 14