Radio & Plasma Wave Instrument (RPWI) Team Meeting

Jan-Erik Wahlund, RPWI Meeting (Prague), Feb. 18-19, 2010

• RPWI Documentation• Twiki home page (secure)• http://space.irfu.se/twiki/bin/view

• Register!• JgoRpwi group

• Only IRF-Uppsala team members can edit (may change)

• All RPWI documentation will by time be stored here

• RPWI Public Outreach page Who?

EJSM/JGO S/C(EJSM WS, January, 2010)

Mass:– Incl. 20% system design– Dry: ≈1500 kg, Total: 4400 kg

P/L: 104 kg (incl. margin), 120-150 W

Power: – GaAs cells >60 m2

Notes:– High Temp MLI on S/C external surface during Venus flybys– Nadir pointing during flybys, except during communication periods

TM:– Ka band– Ganymede circular phase most constraining, > 1 Gbit/day

EJSM project schedule

EJSM/JGO Mission Profile Launch: 2020 (to sync with JEO)

Arrival: 2026 with a VEEGA

Cruise: 6 years

JOI: A Ganymede GA before JOI

– 13 x 230 RJ orbit

– 165 +120 days, Δv ≈ 887 m/s

Callisto Science Phase (57+400 days)

– Resonant orbit with Callisto (15 flybys)

– Both poles, 2.5-2.6 km/s

Ganymede approach & orbit phase

– To Ganymede orbit with CaGaGa-GA (85 days)

– All flybys near 200 km

– Elliptical Orbit: 200 x 10000 km, 141.8° (120 days) leading to 1000 km near circular orbit at end

– Cicular Orbit: 200 km (180 days)

– 1h eclipses foreseen

Impact Ganymede

P/L Operations

SSR antenna use (RA-PWI)

Agreement for passive use– With Lorenzo Bruzzone (SSR lead)– Details to be settled March 11, Trento

Radiation issues

Design requirement (new!)– 85 krad behind 10 mm Al– Design should aim for 150 krad tolerance

● Concern: Requirement keep changing

Shielding mass– ESA estimates 80 kg shielding for 104 kg P/L (confirmed)– ≈ 3 kg for RPWI

Radiation control– ESA will most probably implement a Radiation Control Board– Suggestion: L. Åhlén from RPWI

Radiation test facilities

in Uppsala– Co60 1-10 Rad/min– Electrons, 7.5-15 MeV High dose rate– Protons, 20-180 MeV 150 Rad/min– Protons, < 6 MeV Low dose rate– Heavy ions

JGO Requirements

COSPAR – Maintains a planetary protection policy– Has a dedicated planetary protection panel

ESA & NASA – Has planetary protection policies compliant with COSPAR– Mission lead agency has overall responsibility (ESA for JGO)

Category II: Of significant interest relative to the process of chemical evolution & origin of life, but only remote chance that contamination by S/C could compromise future investigations.

Procedures for Category II ESA may consider bio-burden control for H/W

– Dry heat microbial reduction (DHMR)?● Only penetrator (if selected)?

Recommended scope for bio-burden control– Assembly, testing and launch in ISO 8 clean-room condition

● Transport in clean boxes in between – Perform biological assays during H/W final assembly– Assess temperature/time profiles of manufacturing processes,

especially for items behind radiation shielding● 5h at 125°C reduce by an order of magnitude● Use test program & approved parts list

– Estimate reduction based on agreed bio-burden levels, inactivation rate and S/C radiation dose mapping

Documentation/Reviews

RPWI probably need a dedicated person for Planetary Protection ControlWho?

Again for RPWI: Who?

Funding situation (IRF-Uppsala + KTH)

February 1: Applied for two years to SNSB– TDA:s as well as Management

● LP-PWI mechanics● Radiation facilities upgrade ● Radiation testing● ASIC development activities● MEMS WLP pre-amps for LP-PWI ● Planetary protection activities

– Cost outlined until 2030 (!)

LP-PWI pre-amps development

MEMS Wafer Level Packaged (WLP) technlogy– 5x5x1 mm3, 1g, 10g with 8 mm shielding– Compare PCB, 3x5x2 cm2, 300g with 8 mm shielding– 4 units means ≈ 1.2 kg mass saving– Ångström Microtech AB

● MEMS WLP is TRL 6 ● No problem reach TRL 5 pre-amps by end of 2012

Could also be applied to HF pre-amps if wanted

Pre-amp house (LP-PWI) From M. Dobrowolski &J. Grgorczuk (Warzaw)

HF Rx/Analyzer

Iowa University group is prime

IRFU is looking into how LESIA may participate– Sorry, cannot say more for the moment.