themis mission cdr -ucb, june 14-18, 2004 search coil magnetometer (scm) mcdr alain roux,...
Post on 03-Jan-2016
215 Views
Preview:
TRANSCRIPT
THEMIS Mission CDR -UCB, June 14-18, 2004
Search Coil Magnetometer (SCM)
MCDRAlain Roux, CETP-Velizy
Co-i: O.Le Contel
Technical Manager: B.de la Porte* =>C.Coillot
Lead Engineer: A.Bouabdellah
Technicians: D.Alison & S.Ruocco
*Till june 2004
THEMIS Mission CDR -UCB, June 14-18, 2004
Technical Manager: Bertrand de la Porte
•team management, general schedule
Lead engineer: Christophe Coillot
•SCM support: design, manufacturing:
•Sensors : design, manufacturing, tests,
•PA: electrical design, tests procedures, EM&FM tests.
•Sniffer design, manufact. & tests
Engineer: Abdel Bouabdellah
•ICD&PAIP management, Vibration tests,
•PA: PCB cabling, design of housing,
•manufacturing, PA I/F.
Technician: Dominique Alison
•PA/PCB design,
•Manufacturing sensors,
•I/F PA: design, manufact., tests
Technician: Sébastien Ruocco
•Sniffer & tests:
Technical Manager: Christophe Coillot
•team management, schedule.
•SCM support: manufacturing, schedule,
•Sensors : manufacturing, EM&FM tests,
•PA: tests procedures, EM&FM AIT
•Lead Engineer: Abdel Bouabdellah
•ICD&PAIP management, Vibration tests,
•PA: PCB cabling, manufacturing, PA I/F general schedule. Integrations.
Technician: Dominique Alison
•PA/PCB design,
•Manufacturing sensors,
•EM&FM tests&integrations
Technician: Sébastien Ruocco
•PA: FM tests.
•Sensors: FM tests.
•Integrations
Team re-organisation
THEMIS Mission CDR -UCB, June 14-18, 2004
IN.SCM-1. SCM shall provide a critical test for the role of waves at substorm onset, in various models (with EFI).
Compliance.
IN.SCM-2. SCM shall measure the 3D AC B-field from 1 Hz to 4kHz.
Compliance.
IN.SCM-3. The SCM sensitivity shall be better than 1pT/Hz^1/2 @10Hz , and 0.1 pT/Hz^1/2 @1 kHz.
Compliance. 0.7pT/sqHz@10Hz
0.04 pT/sqHz@1kHz
IN.SCM-5. The transfer function of the SCM sensors (amplitude &phase) shall be known with an accuracy better than 5%.
Compliance. Tests of EM will be made in Chambon la Forêt, end of June.
IN.SCM-6. On each spacecraft the 3 magnetic antennas, shall be held orthogonal by a structure procured by CETP
Compliance. Structure meets specs : mass, vibrations (modeling, and vibration tests)
Sensor requirements
THEMIS Mission CDR -UCB, June 14-18, 2004
Sensibility EM (pT/sqrt(Hz)
0.001
0.01
0.1
1
10
1 10 100 1000 10000Fréquency (Hz)
THEMIS Mission CDR -UCB, June 14-18, 2004
Design includes EPR remarks and numerical simulation results. Interface is completely defined (cf. P. Turin). EM structure delivered by GdTech to CETP: May 17th.
3-axis structure
THEMIS Mission CDR -UCB, June 14-18, 2004
PA Design by 3D+
Mechanical characteristicsMechanical characteristics: : • 2 amplification levels• 3 radiation shielding levelsDimensions: 20 x 20 x 15 (mm)Weight : 15 g
Pre-Amplifier module
THEMIS Mission CDR -UCB, June 14-18, 2004
PA Layout on PCB&box
a
THEMIS Mission CDR -UCB, June 14-18, 2004
Item Specification Status
Search Coil Size
Search Coil Mass
175x175x175 mm
600 g
176x176x176 mm
608 g (+/-8)
Most masses meas.
Pre-Amp Size
Pre-Amp Mass
Pre-Amp Power
80x70x40 mm
200 g
90 mW
109 x 94.9 x 30mm
200 g (measured)
86 mW (measured with EM)
Power &mass summary
THEMIS Mission CDR -UCB, June 14-18, 2004
Operations
• When ON, SCM is continuously measuring the magnetic field up to 4 kHz.
• Once per orbit a calibration is run for 30 secs (default)
• After 60 seconds, the Calibration is automatically turned off.
THEMIS Mission CDR -UCB, June 14-18, 2004
Test Matrix
Model I/F EM EM EM FM FM FM
Item PA SC PA SC+PA SC PA SC+PA
Electric. Verificat. X X X X X X X
Full Calibration X X
Mech. I/F,M, CoG, MoI X X X X
Vibrations Q Q A A
Thermal tests (cycles) Q Q A A
Thermal Vacuum Q.idpu A.idpu
Interface to IDPU X
Pre-integration UCB X X X X
Integration to S/C X X
THEMIS Mission CDR -UCB, June 14-18, 2004
Test plans : SC
After winding of internal tube
Verification of Impedance
Done (EM)
After potting of the magnetic core
Verif. of imped. Magnetic flux resp. (with PA
Done (EM)
Done (EM)
After overall potting Verif. of imped. Magnetic flux resp. (with PA
To be done end of june EM
After 3-axis assembly, and connect. to PA
Transf. funct. (SC in mu-metal box, metrology, vibr., temp. limit,
Full cal. in Chambon
Begin of july EM
After delivery to UCB Therm. Vac (with S/C)
THEMIS Mission CDR -UCB, June 14-18, 2004
Test plans: PA cubes
Single flex Electrical verification
Offset adjustment
Done (EM&FM)
Done(EM)
After cube assembly &potting
Electrical verification
Temperature test*
(-50° - +60°)
Done(EM&FM)
Done(EM)
* Takes into account changes suggested during CDR peer review
THEMIS Mission CDR -UCB, June 14-18, 2004
Test plans: full PA box
After PCB cabling Electrical verification Done
EM
After assembly in the housing
Electrical verification
Metrology
Vibrations
Full range temp. tests
Done
TB done
Done
Done
Connect. with SC Transfer funct.,SC in mu-metal box.
Full cal. in Chambon
End of June
After delivery to UCB Thermal vac. With IDPU
THEMIS Mission CDR -UCB, June 14-18, 2004
Bench test configuration
THEMIS Mission CDR -UCB, June 14-18, 2004
Mag. calibration: Chambon
THEMIS Mission CDR -UCB, June 14-18, 2004
Interface verification at UCB
An interface model has been built and sent to UCB to test I/F to IDPU .
• Same Power, Command, analog output interfaces
• Power and Cal Mode identification by LED
• Cal Signal re-injected to the input
• A signal generator can be connected to each input
THEMIS Mission CDR -UCB, June 14-18, 2004
Pre-integrations at UCB
• After delivery to UCB (Incoming Inspection, Bench Test)
•Sensor in the mu-metal box
•Electrical Integration
•Power ON and functionnal test
Validation can only be done by analysis of telemetry data
I&T at UCB
THEMIS Mission CDR -UCB, June 14-18, 2004
I&T at s/c level
Integration on the spacecraft
• Mechanical Integration of the PA, connection to the boom harness
• Sensor in the mu-metal box
• Electrical Integration (bounding, isolation)
• Power ON and functionnal test
Validation can only be done by analysis of telemetry data
THEMIS Mission CDR -UCB, June 14-18, 2004
SCM tests at s/c level: 1
Extended cable 1.5 m
Antenna in the mu-metal box
pre-ampInitial configuration:
The sensor is inside the mu-metal box, connected to the PA via the boom harness
Requirement: keep the sensor in the mu-metal box until all experiments are integrated in the spacecraft (mission operation test)
THEMIS Mission CDR -UCB, June 14-18, 2004
SCM tests at s/c level: 2
WHAT CAN BE DONE WITH THE SENSOR IN THE MU-METAL BOX?
• Verification of the labelling of axis (X,Y, Z)
• (Re)-verification of the end-to-end calibration
• Phase relation between the 3 components (for the waveforms)
• Measure the conducted noise
• SCM/EField timing reference [and inter-calibration]
THEMIS Mission CDR -UCB, June 14-18, 2004
SCM integr. at s/c level: 3
SENSOR MOUNTED ON THE BOOM
• PA saturated by the 50/60 Hz (except in an EMC chamber).
• No measurement possible but a major failure would be detectable.
INSTALLATION OF THE MLI: preferably at the last moment, before s/c vibration tests.
THEMIS Mission CDR -UCB, June 14-18, 2004
EMC tests at s/c level
• CETP can help analyse the AC radiated noise around the spacecraft.
• A « magnetic sniffer » has been built and delivered to UCB.
• In order to avoid the saturation by the 50/60 Hz, the analysis is separated into two bandwidths: below 50 Hz and above 300 Hz (5th harmonic).
THEMIS Mission CDR -UCB, June 14-18, 2004
SCM integr.; team support
• The SCM team will support all critical activities, for the integrations.
• However, due to the large number of satellites, a strategy should be implemented to limit the number of travels, cost and time spent
• Support EM integrations in any case
•The FM will be delivered 3 by 3 and the level of support for each test will be agreed upon with UCB
Capability of remote access/support should be implemented
THEMIS Mission CDR -UCB, June 14-18, 2004
SCM schedule- Key dates
EM delivery to UCB July 2004
EM pre-integrations at UCB
July 2004
3D cubes (FM) delivery to CETP
July 23th, 2004
FM1,2, and 3 availability: Sept. 24th, 2004
FM4,5, and 6 availability: Nov.10th, 2004
THEMIS Mission CDR -UCB, June 14-18, 2004
Status of questions/RFA’s
SCM-1
Ground
ing &
testing
Concern that grounding and shielding is not yet defined—need to make sure all documents are consistent. This was an action from the last review, but understand that this is common for CDR-level fields missions.
•Grounding review (end of may) UCB&CETP agreed upon:•Coils&shields of each SCA GND (not to CGND)•Thermal blanketCGND•Overall shielding of boom cable
by conductive tape. •Backshell of PA connector also shielded•No need to shield SCA connect.
SCM-2
Simult. Firing of actuat.
Ensure that both actuators are fired simultaneously, at temperature and voltage extremes during testing. (Slavin—based on Double Star dual boom deployment failure.)
The mag-booms are released simultaneously
THEMIS Mission CDR -UCB, June 14-18, 2004
Status of questions/RFA’s
SCM-3
Tests of 3D components beyond predicted levels
CETP should ask 3D to test components beyond the predict levels. Most electronic parts are tested at greater levels individually than at assembly level.
Done; new test procedures defined with UCB&3D; temperatures ranges extended by +/-5°
SCM-4
PCB mounted on 4 corners
PCB mounted on four corners. Is this adequate for limit loads for deflection [probably okay, ~4mm standoffs] and strength? Recommend calculation to ensure populated board does not exceed strength limits.
It is not typical to calculate the strength requirement of boards. Vibration test performed successfully.
SCM-5
Wires inside PA box
Wires from connectors to board are long. The wires should be laid out differently (increase board size, glue the longest wire on the PCB?)
Longest wires are now glued
THEMIS Mission CDR -UCB, June 14-18, 2004
SCM-6 details
SCM-6 (cnd.)
Summary of THM-SYS-005:
• SC(antennas) qualified by CETP (thermal cycling) without vacuum. TV test at s/c level.
• PA qualified in temperature (currently done) by CETP, without vac.. TV done at UCB, together with IDPU.
THEMIS Mission CDR -UCB, June 14-18, 2004
Status of questions/RFA’s
SCM-6
Thermal vac./thermal air cycling
UCB and CETP need to have an agreement on how many thermal vacuum or thermal air tests cycles are performed before delivery (by s/c CDR)
THM-SYS-005 calls out the required cycles & temperatures
SCM-7
Thermal levels
Thermal levels should come from document such as environmental requirements.
We are adding a reference to "THM-SYS-005 Instrument Payload Verification Plan and Environmental Test Specification" to the ICD
SCM-8
Test sequencing
Details of test sequencing, configuration (are sensors connected to pre-amps during testing)-Teams have begun to discuss; more meetings between the I&T lead, PM, SE and CETP would be beneficial.
Marc Kaylor (Swales) is drafting the basic probe flow, so that Rick Sterling can insert the details of the SCM tests.
THEMIS Mission CDR -UCB, June 14-18, 2004
SCM-9 Review EMI/EMC levels relative to FAST
Rick Schnurr volunteers to review EMI/EMC levels relative to FAST, and tell UCB which levels may present difficulties (noise in the chamber).
Data has been provided to Rick.
SCM-10 Populating boards in advance
Recommend populating boards in advance of 3D cube arrival, to help schedule
Agreed
SCM-11
Nickel plating of small objects far away from sensor
Would be beneficial in magnetics plan to note: don’t consider nickel plating small objects far away from sensor (such as nickel coating on 3D cubes).
Although not specifically called out in the magnetics plan, the use of nickel plating has been tested and tracked. The SCM Pre-Amp 3D Plus modules were tested in Braunshweig in Dec. and determined to have a magnetic moment well within the requirements for THEMIS.
Status of questions/RFA’s
THEMIS Mission CDR -UCB, June 14-18, 2004
SCM-12
Thermal treatments on e-box.
Thermal treatments on e-box is in need of definition.
The thermal treatments have now been defined by UCB. The top of the preamp will be anodized but the rest of the box can remain alodine.
SCM-13
Chambers used for EMI/EMC tests
The chambers used for EMI/EMC tests usually do not present a clean AC magnetic environment. This is why tests on subsystem with a search coil inside a large mu-metal chamber are important when a careful verification is needed. Such a facility exists in France at Chambon-la-Foret.
We believe this is a recommendation to do what we have planned. So the response is to keep going as planned.
Status of questions/RFA’s
THEMIS Mission CDR -UCB, June 14-18, 2004
• Ressources (mass & power) are compatible with allocation.
• Tight schedule, yet delivery dates for EM and FM are compatible with the schedule of the project.
• PA cubes (EM) meet requested performances. PA box passed temp. & vibr.tests ; no problem.
• Sensitivity meets specs
• Antenna structure (EM) delivered. Meets specs.
Summary
top related