THEMIS PROBE
This presentation is the property of its rightful owner.
Sponsored Links
1 / 14

THEMIS PROBE FM2 PRE-ENVIRONMENTAL REVIEW DC MAGNETICS TESTING Michael Ludlam Magnetics Lead PowerPoint PPT Presentation


  • 64 Views
  • Uploaded on
  • Presentation posted in: General

THEMIS PROBE FM2 PRE-ENVIRONMENTAL REVIEW DC MAGNETICS TESTING Michael Ludlam Magnetics Lead University of California - Berkeley. Introduction. Component Magnetics Is the probe ready for the DC Magnetics test? Facilities Are the facilities ready for the DC Magnetics test?

Download Presentation

THEMIS PROBE FM2 PRE-ENVIRONMENTAL REVIEW DC MAGNETICS TESTING Michael Ludlam Magnetics Lead

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Themis probe fm2 pre environmental review dc magnetics testing michael ludlam magnetics lead

  • THEMIS PROBE

  • FM2 PRE-ENVIRONMENTAL REVIEW

  • DC MAGNETICS TESTING

  • Michael Ludlam

  • Magnetics Lead

  • University of California - Berkeley


Introduction

Introduction

  • Component Magnetics

    • Is the probe ready for the DC Magnetics test?

  • Facilities

    • Are the facilities ready for the DC Magnetics test?

  • Requirements

    • Do we know what the requirements are?

  • Test Procedure

    • Do we have a reviewed procedure ready?


Component magnetics testing

Component Magnetics Testing

  • Status of FM2 Probe components:

  • All Instruments including IDPU have been magnetically mapped. Some bus components have been mapped – BAU, AEB, Battery (QM).

  • One problem found with BEB board in IDPU found to have magnetic transistors. All BEB boards have been degaussed separately and verified to be non-magnetic.

  • BAU and AEB boxes found to be slightly more magnetic than expected – due to relays.

  • Baseplate with RCS piping and valves have not been degaussed – a known magnetic offender with latch valves.

  • Overall, units are either in or close to magnetics budget.


Facilities

Facilities

  • Coil structure has been strengthened and tested for probe.

  • Night time stability measurements have been taken to verify stability of environment.

  • UCB provided MGSE for holding probe has checked by JPL for fit and magnetics.


Requirements

Requirements

Requirements from Magnetics Contamination Control Plan (THM-SYS-002D) derived from the Mission Requirements Document (THM-SYS-001).

  • 5nT spacecraft field at location of FGM (M31a).

  • Stability of spacecraft field shall be less than 0.1nT over 12 hours at the location of the FGM (M31b).


Test procedure

Test Procedure

  • Test Procedure written by Pablo Narvaez (JPL) incorporating UC Berkeley DC Magnetics test procedure originally written for the purpose.

  • THEMIS Probe DC Magnetics Test Procedure (JPL D-33980).

  • Procedure is ready.


Test flow

Test Flow

Night 1

5nT requirement

As received survey

Repeated after probe vibration

Deperm Spacecraft

Post deperm survey

5nT requirement

Expose spacecraft to Earth’s field & survey

0.1nT stability requirement


Test flow1

Test Flow

Night 2

Power up probe

5nT requirement

Powered probe survey

0.1nT stability requirement


Magnetic survey

Magnetic Survey

Vertical Mapping Setup

Horizontal Mapping Setup

Location of magnetometers: 1.5m from cg (for Analysis) and 2m from edge (FGM location)


Deperming

Deperming

Deperming done using slowly varing DC field whilst probe is rotated in the x-y plane. The deperm is repeated in the x-z plane. The maximum field for the deperm will be 15 Gauss. If this does not achieve good results, it is possible to increase this to 20 Gauss.


Perm field test

Perm Field Test

Using the Earth’s field as a perm field the probe will be exposed to more than maximum field it will see in space. Comparing the field measured with the probe and without the probe in a given location will show the distortion of the field caused by the probe. This will give the stability we are likely to see from perming over an orbit.


Powered test

Powered Test

The probe will be powered using the fully charged battery and a magnetics survey test run again to see what field is induced by the probe from the currents flowing in the spacecraft.


Test personnel

Test Personnel

Pablo Narvaez – JPL

Bob Snare – UCLA

Ellen Taylor – UCB

Michael Ludlam – UCB (by phone)


Summary

Summary

  • Component Magnetics

    • Units mapped at UCB generally look magnetically clean.

  • Facilities

    • JPL DC magnetics coil facility is ready.

  • Requirements

    • 5nT spacecraft field at location of FGM.

    • 0.1nT stability over 12 hours at location of FGM.

  • Test Procedure

    • THEMIS Probe DC Magnetics Test Procedure (JPL D-33980) is ready.


  • Login