POWER PROCESSING UNIT SWITCH-ON STRATEGY AFTER SPACECRAFT SEPARATION (ARTES AT REF. 4F.099)

Status

ISSUED

EMITS REFERENCE

Program

ARTES 5 Sub-El. 5.1

Price Range

200-500 KEURO

Description

Objective:

The objective of the activity is to allow Power Processing Unit (PPU) switch on as quickly as possible after spacecraft separation.

Targeted Improvements:

To avoid long drifts during mission phases (days).

Description:

High power units like PPUs have the risk of Corona at first start-up if the pressure is too high. Traditionally, such units are therefore only switched on after several days of depressurisation and outgassing. With full electric orbit raising, there is a need to start PPUs within a few hours after separation, in order to start the electric orbit raising as early as possible. The days of depressurisation and outgassing lead to a decay of the spacecraft's orbit while waiting for the operational requirements to be met for switching on the plasmic propulsion.

After choosing a EOR missions profile and a PPU existing design, it is proposed to define the conditions (temperature, pressure, etc.) required to switch-on the PPU as early as possible after separation, without Corona.

The proposed work logic is:

  • Selection of a reference PPU design & reference EOR mission profile;
  • Define the pressure profile using materials outgassing rate and any other parameters driving pressure decay (manufacturing, temperature, etc.)
  • Definition of max pressure allowed to ensure no risk of Corona - analytically, or by test;
  • Issue of some recommended methods for a safe start-up after separation without design change - possibly by measuring temperature, pressure, time, etc.
  • Validation of this method by test;
  • recommend design changes if necessary.

Tender Specifics