1. GoetzFIELDS iCDR - Analyses Solar Probe Plus - FIELDS System Analyses Instrument CDR Keith Goetz University of Minnesota Goetz@umn.edu 1

2. GoetzFIELDS iCDR - Analyses Reliability Reliability analysis performed by Project before iPDR –Resulted in splitting FIELDS into two halves – FIELDS1 and FIELDS2 FIELDS1 is the master FIELDS2 is the slave – but can run on its own –A single failure cannot cause a total loss of FIELDS science FIELDS has no limited life items –EEPROMs allow ~100,000 write cycles – will use <100 FIELDS EGSE is safe – store bought 2

3. GoetzFIELDS iCDR - Analyses FIELDS1/FIELDS2 block diagram 3

4. GoetzFIELDS iCDR - Analyses Radiation Radiation analysis performed by Project –Analysis done for all locations –Results are detailed in EDTRD Generally benign solar wind –EEE parts are safe from TID – all below 40kRad –MEP20kRad –V1234530kRad –SCM40kRad Some SE issues could result in minor loss/errors in data Some SE issues (latch-up) could require circuit breaker – now in EM designs –Coax dielectric TID testing has been done for dielectric breakdown in high radiation environment outside S/C body 4

5. GoetzFIELDS iCDR - Analyses Dust Dust analyses performed by Project –Analyses done for all locations –Interior parts (e.g. MEP) no issue –Exterior parts are generally blanketed and safe –Dust gun testing has been done on, for example, V1234 heat shield Pin-point punctures made but minimal loss of function (holes are tiny) 5

6. GoetzFIELDS iCDR - Analyses EMC EMC/ESC/MAG are big issues for FIELDS –Discussed previously EMC wants a well controlled picket fence –Failing that, RFS wants deep 50kHz troughs when doing science ESC wants a conducting S/C exterior –Failing that, S/C heat shield will conduct when close to the sun MAG wants low remnant fields – low AC levels –Failing that, MAG wants stable DC fields and good S/C characterization 6