1. COSIMA Scientific Objectives

tions for models of the origin and evolution of comets and thereby of the solar system.

• the chemical and physical states of the elements.

• variation of the chemical and isotopic composition between individual particulates.

• changes in composition that occur as functions of time and orbital position.

• variability of the composition of different comets by comparing the results to those obtained previously from comet Halley

and in future from the STARDUST (Wild-2) and CONTOUR (Encke, SW-3, d’Arrest) comets

• molecular composition of the organic phase of the solid cometary particles

• molecular composition of the inorganic phase of the solid cometary particles

• the chemical state of the organic matter, characterized by its saturation degree, oxidation state, and bond types

• the chemical & physical states of the elements.

which in turn will allow:

• the comparison of the composition of the solid particles to the elemental and isotopic composition of the neutral and ionized atmosphere of the comet.

• insight into the molecular composition of the inorganic phase of the particulates, with emphasis on the degree of mineral forma-tion

• the exobiological relevance of the organic matter as possible organic precursors with free enthalpy and as the driving force for self-organization.

Initial check-out:

• need several days wait for good vaccum (better 10-7 mBar) to be established

• straight forward

• no special operations needed

• all part of on-board software

Maintenance:

• needed for Liquid metal ion-source

• and TMU motors

• fully autonomous operation for at least 30 minutes, maybe longer as LAB experience indicates • currently envisaged opportunities are satisfactory

Early science operation:

• short, low power operations to expose target(s) to cometary dust flux

• self controlled and autonomous analyses for target classification

• job definition by ground control, autonomous and automatic job scheduling and execution

Main science operation:

• starts for COSIMA with first target covered to about 1% with dust

• 24h / 24h autonomous operation upon ground controlled task definition

• autonomous power profiling from own database and external requirement (within reasonable values)

• full time operation needed due to high sensitivity of instrument to analyze bulk material

• autonomous on-board characterization of dust sites assures widest variety of science return

3.

interface compliance

•

COSIMA complies with all S/C interfaces

POWER INTERFACE

Hi-Rel DC/DC Converters (Interpoint) used for COSIMA FM Inrush-current limiters keep surge current within nominal limit COSIMA total power consumption adaptable by sub-unit switching Main-Power and KAL inline with EID-A, Section 2.4, and with limits

given in EID-B Pin-out of power interface connectors cross-checked by DORNIER DATA INTERFACE

Custom FPGA handles all data-interface traffic

Redundancy concept followed with nominal and redundant drivers/receivers Rad-hard 26C31 and 26C32 drivers/receivers used within COSIMA

COSIMA EQM data interface successfully checked against ROSIS simulator. Pin-out of data interface connectors cross-checked by DORNIER

Data interface inline with EID-A, Section 2.7.4 MECHANICAL INTERFACE

For COSIMA STM physical properties were measured and documented within Dimensional Control Worksheets. No changes for PFM.

For COSIMA the following models are produced and used for design qualification

Structural and Thermal Model delivered

Electrical Verification Model for full function verification +vibration

not deliverable

may become flight spare

Electrical Qualification Model electrical mechanical, software, EMS & DC representative

delivered

Proto- Flight Model will be acceptance tested

5.

resource budgets

COSIMA is expected to stay within its allocated resources

MASS: allocated: 17.3 kg

EVM measured mass is 18920 g projected for FM are 19090 g

POWER: allocated max.: 20.6W

long peak power < 22W, short peak power < 42W COSIMA inrush current is limited to 1.5 A

After 8 ms max., current will be less than 0.79 A After inrush, COSIMA is within the peak power limits

Telemetry:

COSIMA will stay within limits and produce steady telemetry flow

Temperature Range: COSIMA is within globally controlled area

COSIMA’s sensitive target storage area is thermally decoupled

COSIMA will find way to live with current or slightly modified

situation

S/C Interface Protocol, Services, ( Refer to EID-B, table page 15)

• software infrastructure for all services available and tested

• detailed definition pending in some cases till hardware becomes available for full lab-tests

Service # Comment State Tested Comment

1 telecommands implemented tested with ROSIS 3 housekeeping implemented tested with ROSIS 5 event reporting implemented tested with ROSIS 6 memory management implemented tested with ROSIS 9 time management implemented tested with ROSIS 17 test service implemented tested with ROSIS 18 context transfer implemented tested with ROSIS

20 science data transfer infrastructure tested with ROSIS EDF-definition TBD

21 private telecommands implemented tested with ROSIS

EGSE Status

hardware

• 2 devices will be delivered

• Hardware complete

• cables available

Software

• User interface completed

• EQM-functional complete no SW for science data handling

7.

operational modes

COSIMA operational modes:

• operational modes are clearly centered around COSIMA hardware items

• dust collection is lowest power mode

• separate mode elements for liquid metal ion gun heating, running, and shut down

• independent COSISCOPE operation

• independent target manipulation in analysis modes (highest power)

• power consumption can be adjusted by sequential rather than parallel operation of hardware items (power vs. Time tradeoff)

• instrument flexibility and autonomy creates numerous detailed operational modes

8.

schedule

COSIMA will keep its delivery dates (current best estimate)

needed some doing!

STM is delivered

EQM is delivered

EQM program will be split into two units:

•

EQM with project required properties

•

EVM with physics requires properties, and for mechanical

qualification