European Space Agency

Objectives

Improvement of ADE4 performance and adaptability to Eurostar 3000 SX spacecraft and cost saving in order to offer an enhanced competitiveness.

In the frame of Eurostar 3000 SX with the objective to save mass and recurring cost, trade-off performed at platform level have shown than it is possible to delete two boards in each ADE4 equipment.

Because a new arrangement of MPIU functions, PFIE board can be deleted. According to these evolutions ADE4 can be reduced to a unit including 5 modules.

  • CV BC/TC module including auxiliary supplies, 1553 data bus coupling, and Telemetry and telecommand capabilities,
  • CPSE module drives the propulsion sub-system,
  • MDE module drives the spacecraft mechanisms steeping motors,
  • SADE module drives Solar Array Drive Mechanism,
  • WPC module in charge to interface with momentum wheels.

On Eurostar 3000 two ADE4 with 6 modules each are implemented on the spacecraft. The need for an Eurostar 3000SX platform becomes two ADE4 with only 5 modules each.

According to the above status, a efficient way for cost and mass saving is to merge ADE4 Nominal and redundant equipment in a single box.(ADE5)

Savings are estimated at unit level to about 4,6 Kg for the mass and 15% for recurring cost. But other impact as mass saving for the harness is also significant.

Challenges

ADE5 EQM is composed of 10 modules. The assembly is a mix of boards coming from various ADE 4 development stage but each board is fully representative of the future Eurostar 3000 SX flight units.

CHANNEL B:

  • CV BC/TC A is coming from ADE4 EQM4,
  • CPSE A is coming from ADE4 EQM4,
  • MDE A is coming from ADE4 EQM4,
  • WPC NG A is coming from ADE4 EQM4 (new generation boards re-routed in the frame of implementation of HS1840ARH and PHR1206),
  • SADE NG A is coming from ADE4 EQM4 (new generation boards re-routed in the frame of implementation of HS1840ARH and PHR1206),
  • WPC B is coming from current Eurostar 3000 EQM3.

CHANNEL A:

  • CV BC/TC B EQM module will be manufactured in the frame of this project according to ADE4 EQM4 standard (current flight model standard),
  • CPSE B EQM module will be manufactured in the frame of this project according to ADE4 EQM4 standard (current flight model standard),
  • MDE B EQM module will be manufactured in the frame of this project according to ADE4 EQM4 standard (current flight model standard),
  • SADE B is coming from current Eurostar 3000 EQM3.

As reported above channel A of ADE5 consists of boards manufactured with the last Flight Model standard which have been never submitted to mechanical environment qualification tests. The various modules are coming from EQM4 only submitted to ESD Tests (WPC NG & SADE NG) and the others modules (MDE 10Hz, CPSE, CV BC/TC) will be produced in the frame of this contract.

At the opposite channel B included old generation boards which have been already submitted to mechanical environmental qualification campaign.

In conclusion the ADE5 channel A is fully representative of future ADE5 flight standard and therefore qualification criteria is linked to “EQM channel A” results.

Benefits

As stated above the main objective is to improve ADE4 performance and adaptability to Eurostar 3000 SX spacecraft and cost saving in order to offer an enhanced competitiveness.

Savings estimated at unit level to about 4,6 Kg for the mass (harness not included) and 15% for recurring cost.

Therefore with ADE5 evolution it can be stated that mass and cost saving will for sure enhance competitiveness of Eurostar 3000 SX spacecraft against other PFs available on the market.

Features

As stated above ADE5 is formed of two ADE4 without PFIE functionality. ADE5/ADE4 equipment achieves, through the MIL-STD-1553B system bus, the interface between the central Spacecraft Computer Unit (SCU) and most satellite actuators and a part of the platform dedicated Telemetries/Telecommands (TM/TC).

It also contains electronic regulated heater channels. The ADE5/ADE4 performs, under the system bus control, the following functions implemented on various boards:

  • On CVBCTC Board: Main converter generating secondary supplies for internal and external use, the MIL-STD-1553B system bus interface, two Telecommand Matrix.
  • On SADE (Solar Array Drive Electronics) Board: Solar Array Drive Mechanism (SADM) interface achieving stepping motor commands and performing the position acquisition.
  • On CPSE (Combined Propulsion Subsystem Electronics): generation of the Reaction Control Thruster (RCT) commands and the ON/OFF commands for Latching Valves (LV) and Liquid Apogee Engine (LAE). The Ion Propulsion Subsystem (IPS) fine Thermal Control Electronics (TCE) function is also implemented on CPSE board.
  • On WPC Board: xenon Pressure Regulation Electronics (PRE) for the Ion Propulsion Subsystem (IPS), Wheel Control Electronics (WCE) making the interface with up to 4 inertial wheel and Cross Strapped Temperature Acquisition (CSTA) electronics providing TEMA interface for PFIE function.
  • MDE (Motor Drive Electronics) board: driving of all the spacecraft mechanisms steeping motor, Antenna Pointing Mechanisms (APM)) and performing the corresponding position measurements.
  • PFIE (only available for ADE4) (PlatForm Interface Electronics) board: providing Telecommands/Telemetries to the platform.


click for larger image

Plan

Development plan logic is as follows:

KO => Presentation of activities to be performed

  • Electrical redesign mainly new accommodation due to PFIE removal
  • Mechanical redesign: merge of two ADE4 units
  • Thermal redesign: merge of two ADE4 units
  • Radiation redesign: merge of two ADE4 units
  • Preparation of design documents
  • Issue of manufacturing documents based on new concept
  • Preparation of BDR Data Package

BDR => Delivery and review of BDR data package

  • KO for EQM manufacturing activities
  • Documents update as result of BDR outcomes
  • Issue of Test Plan & Test Procedures
  • Preparation of MTR/TRR Data Package
  • MIP EQM

MTR/TRR => Delivery and review of MTR/TRR data package

  • KO for ADE5 qualification
  • Documents update as result of MTR outcomes
  • Thermal model correlation
  • Formal qualification:
    • Initial functional & Electrical tests
    • Vibration & shocks tests
    • Thermal Vacuum Tests
    • EMC test
    • Final Functional & Electrical tests
  • Issue of qualification tests reports
  • Preparation of FR Data Package

FR => Delivery & review of Final Review data package

  • Documents update as result of FR outcomes
  • Issue of final report

Current status

Currently the project is finished. Final Review already held. Results and in particular NCRs raised during qualification reviewed. In general ADE5 qualification is considered successful. Last remaining open actions, have been closed as follows:

  • Additional EMC tests requested => Additional EMC tests have been performed.
  • Still to clarify some issues related to PSA => Last PSA clarifications included within FR Part2 MOM.
  • Final report missing => Final Report delivered.

Status date

Tuesday, December 30, 2008 - 14:00