BepiColombo/MMO: PWI/WPT-SPWI Kanazawa Meeting [Mar 2006]

WPT-S

WPT-S

MEFISTO-S

MEFISTO-S

[WPT: Team members]

Lead Co-I Y. Kasaba (JAXA) Manufacturer NIPPI

[PWI] K. Ishisaka, T. Okada (Toyama Pref. U.) A. Matsuoka, T. Abe (JAXA) L. Blomberg (KTH [MEFISTO]) M. Moncuquet (LESIA [SORBET])

[System] K. Komatsu, Y. Morita (JAXA)

With the aide of PWI team members & MMO system members

[WPT: Team members]

Lead Co-I Y. Kasaba (JAXA) Manufacturer NIPPI

[PWI] K. Ishisaka, T. Okada (Toyama Pref. U.) A. Matsuoka, T. Abe (JAXA) L. Blomberg (KTH [MEFISTO]) M. Moncuquet (LESIA [SORBET])

[System] K. Komatsu, Y. Morita (JAXA)

With the aide of PWI team members & MMO system members

WPT-S 15m x 2MEFISTO 15m x 2

PWI/WPT (Wire Probe anTenna)PWI/WPT (Wire Probe anTenna)

BepiColombo/MMO: PWI/WPT-SPWI Kanazawa Meeting [Mar 2006]PWI/WPT (Wire Probe anTenna)PWI/WPT (Wire Probe anTenna)

Mechanical – past Design　 *Vertical　 *Latch release: wire cutter with Pyro　 *After the release: Stopped by the tension between “wire” & “spring in Holder”　 *Plane-gear mechanism

BepiColombo/MMO: PWI/WPT-SPWI Kanazawa Meeting [Mar 2006](1) Progress from the last design meeting (Sep. 2005)

<<<Mechanical>>>*Overall Design: 3 changes　 - “Horizontal”: reduce the sun-lit part　 - Latch: 　 released by “motor, without Pyro”　 - Addition of “spacer”

*Mass reduction study: failed　 O Plane-gear 　 600g at this moment　 ? Worm-gear 　　 630g (structure: -15g, gear ： -30g, motor: +75g ）

A/I: 　- “Light-weight motor” – Torque requirement is Margine = x4 at Retraction in full-extension [Heritage of MAST design]- Reduction of the required torque: *reduction of torque margine? *reduction of spin rate at the full extension?

[depending on initial centrifugal force & attitude stability of the spacecraft]

*refine of the requested retraction

BepiColombo/MMO: PWI/WPT-SPWI Kanazawa Meeting [Mar 2006](1) Progress from the last design meeting (Sep. 2005)

<<<Mechanica>>>*Test of the Latch mechanism

Static load test: OK for “<53G”

　　 A/I ：　 Dynamic load test(based on the issued tentative environment condition)

*Wire: Thermal-shock test – No problem

　 A/I ： Strength test @ high temperature　　　 Establishment of the contact to the sphere　　　 Def. of I/F & Installation to the spacectaft

Load direction

BepiColombo/MMO: PWI/WPT-SPWI Kanazawa Meeting [Mar 2006](1) Progress from the last design meeting (Sep. 2005)

<<<Thermal>>>*MTM It is not updated after September 2005

A/I: Update of MTM > Definition of I/F to Side/Lower panels> Update of I-ICD & CDD

<<<Electrical>>>*Harness/Connector: Trough-hole at the lower deck

Connector & harness at the “top-panel” of WPT-SA/I ： Def. of “Stepping motor” (incl. torque margine, mass, EMC)

<DC motor requires safety measure for over-current.>

<<<Material [with MEFISTO]>>>*Surface sample: Photo-electron / 2nd electron yield will be measured.

A/I: next week – Photo-electron distributionFuture – Amount of Photo-electron / 2nd electron yield

<<<Numerical evaluation>>>*Attitude analyses: 　　 Preliminary analyses is “OK”.　　 A/I: incl. Despun & non-symmetric extension

BepiColombo/MMO: PWI/WPT-SPWI Kanazawa Meeting [Mar 2006](3) Development plan in 2006

<Mechanical> Establishment of “key parts design”Finish of the Environment test of BBM & MaterialsUpdating (& reduction) of Mass

<Termal> Update of MTM, Establishment of the wire strength in High-T

<Elec.> Establishment (& reduction) of Monitor items[= establishment of MAST/WPT-E]

Establishment of the Motor power production from 50V-bus[= establishment of MAST/WPT-E]

Establishment of the control scheme at the extension[= establishment of basic design of software on MDP]

(5) Major request to System / Other subsystems & payloads<Mechanical> Definition of I/F

Definition of safety requirement (torque margin, strength margin)Purging for MoS2???

<System> Spin axis direction, Reduction of surface charging

Appendix. Current Resources<Mass> (without margin)

*Assigned mass 545g (without margin)*Current design 600g

BepiColombo/MMO: PWI/WPT-SPWI Kanazawa Meeting [Mar 2006]

“+-4mm move”might be expected.