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Objectives
A Mechanically Pumped Fluid Loop loop Flight Experiment (MPFL-FX) is proposed to be flown as Technology Demonstrator Program (TDP) on the Alphasat mission.
Under ARTES8 PP17.2 pre-development Bradford Engineering is developing and qualifying the single-phase cooling technology for the Alphabus platform.
As the TDP possibilities did not allow to fly a full-sized MPFL with deployable radiator (DPR), it is proposed to fly the most critical components of the MPFL technology (e.g. the pump, the by-pass assembly, the reservoir, the control electronics and the cooling fluid) in a scaled-down version of the originally foreseen full size loop on-board Alphasat (without the large deployable radiator).
The main MPFL-FX objective is to carry-out the on-orbit life testing of the MPFL components in order to increase its acceptance with respect to future customers. The foreseen on-ground accelerated life tests on the mechanical components and on the fluid are still subject to numerous discussions. Furthermore, the MPFL-FX will provide in-orbit verification of microgravity and radiation effects.
The TDP is designed as a experiment box and E-box with very simple mechanical and electrical interfaces and minimised interaction with the satellite. This “piggy-back” approach will enable in-orbit life test of the components of the MPFL without any impact on the other Alphasat payload in case of MPFL failure.
MPFL-FX design
Benefits
The MPFL provides a modular single-phase cooling loop design, which can be used for a variety of applications within a 3 to 6 kW payload range. As a result of this approach, the qualified equipment will be suitable for multiple applications, using the latest state-of-the-art technology. This comprises not only telecom spacecraft, but also e.g. planetary missions.
The Alphasat Flight Experiment will provide essential on-orbit demonstration of the most critical technologies.
Features
With reference to the depicted diagram, the MPFL-FX (scaled-down MPFL flight experiment on-board Alphasat) consists of the following components:
- Pump and Motor (without redundancy)
- Accumulator
- 3-way Valve with position sensor (without redundancy)
- 2 Pressure transducers
- Integrated Electronics (instead of separate Pump Package and By-Pass Assembly E-boxes)
- Connecting tubing
- Coolant
- 2 Fill and Drain Valves
- Several temperature sensors
- Loop Cold Sink
Scaled-down single-phase MPFL (no redundancy) without PHX (no heaters on MPFL tubing) with fixed radiator (no deployable radiator) as RHX
Challenges
The main issue in the project is the pump, which is the “heart” of the MPFL. As the @Bus reliability and lifetime requirements (i.e. 15 years) are extremely severe, this puts highly challenging requirements on the pump design (bearings, motor).
The baseline selected MPFL pump is a design with a demonstrated accelerated life test for over 11 years and successful flights on multiple space missions. Furthermore, the selected coolant is a fairly new engineering fluid that finds its first space application in the MPFL.
Plan
The MPFL-FX design is established in order to define the feasibility of the experiment in terms of accommodation on the @SAT. Analyses have been made to justify the design and compatibility with the @SAT requirements.
Current Status
The Phase A and Phase B0 study were successfully closed in July 2009. Unfortunately, this Technology Demonstrator Program has not been selected to be flown on-board Alphasat. Other opportunities on-board other satellites are currently being investigated.