Brayton Subsystem

A Cold Box which houses the Brayton Machine The electronics that drives the Brayton Machine is called the Motor Drive electronics. It is physically integrated onto the Electronic Unit and is part of the Electrical Sub-system described in section 3.4. The hardware necessary for the on-orbit replacement of a Brayton Machine is called the Brayton Airborne Support Equipment (BASE). It is composed of - A Brayton Machine Exchange Equipment (BMEE) which contains the spare Brayton Machine - A Nitrogen...

Figure Melfi External Interfaces description

Table 3.1 -1 MPLM and ISS services for MELFI Table 3.1 -1 MPLM and ISS services for MELFI Figure 3.1 2 MELFI Functional block diagram Figure 3.1 2 MELFI Functional block diagram Cold Box Front panel with the Cold Box and the Brayton Machine behind Figure 3.1 3 MELFI Front View Schematics Cold Box Front panel with the Cold Box and the Brayton Machine behind Figure 3.1 3 MELFI Front View Schematics Figure 3.1 - 4 MELFI Flight Model with Acoustic Pad and both Tissue Panels

Riu

The over-temperature switch is common for both power buses (MAIN & AUX). The safety loop switch logics implemented in the RIU. It can be noticed that in case of over-temperature followed by a power bus switching, a restart of MELFI is operated because power removal resets the internal restart inhibit.

MELFI Water Loop

The MELFI Water cooling Loop is part of the RSS and provides heat exchange fluid to the Brayton S S and the Electronic Unit. The schematics of the MELFI Water Loop are represented in figure 3.5 2. The Low Temperature Water supply is split into two parallel branches inside the Brayton S S 1 3 of the inlet flow-rate is flowing through the Motor Heat Exchanger (MHX Brayton Machine) and 2 3 of the flow-rate is passing through the Water Heat Exchanger (WHX Cold Box). Quick Disconnects (QDs) are...

Dewar ASE

6.4 Nitrogen fill & Purge Equipment 6.5 Brayton Machine Exchange Equipment and 6.5.1 Brayton Airborne Support 6.5.2 BMEE 6.6 COLD 6.7 Brayton Machine 6.8 Cold Box front 6.9.1 Dewar 6.9.2 Cross 6.9.4 Box 6.9.5 Sample 6.10 Thermal 6.11 Foam 6.12 utility Interface Panel 6.13 Pass-Through 6.14 RIU Switch 6.15 Rack Interface Unit 6.16 Temperature Data 6.17.1 Cold Gas Regulation 6.17.2 Load Heat 7 7.1 Corrective in-flight 7.1.1 Electronic Unit 7.1.2 Brayton Machine 7.1.3 Dewar De-icing 7.1.4...

Rack Subsystem

The Rack subsystem is composed of the following H W items - The 6-post ISPR which is the rack primary structure, - The mechanical supports brackets, slides, for the attachment of the MELFI elements to the rack, - The cooling water loop with thermal insulated tubing and a two positions calibration manual valve for the optimization of the coolant flow, - The electrical harness installed on the rear part of the rack, - The Stowage Compartment installed on the left of the rack. The rack...

Melfi Sw overview and Payload Modes

The first information needed to control the MELFI, either from the data bus, or the CPI, is the Payload Mode. The allowed operations and actions are related to the Payload Mode some action s is authorized in some modes and not in others. Permanently, the Payload Mode can be obtained both from the telemetry received from MELFI and from the CPI displays. The management of MELFI is based upon five payload modes - The Configuration mode is in charge of the initial configuration of the payload...

Melfi Subsystem Breakdown

The MELFI consists of the following subsystems Brayton subsystem BSS produces cooling Dewar subsystem DSS distributes cooling and provides the cold volume Electrical subsystem ESS provides power and command control Rack subsystem RSS provides mechanical accommodation for other sub-systems and the Stowage compartment Utilization UTI provides accommodation for samples and also supports the on-orbit crew operations Software SW centralized and housed by the electronic unit. Each subsystems is...

Electrical Subsystem

Temperature Architecture

The Electrical subsystem is in charge of the control of the overall MELFI system and of the supply of electrical power to the Brayton Machine Motor and control electronics. The MELFI electrical subsystem ESS is composed of the following main items The Electrical Unit EU which gathers - The Control and Data Handling Unit CDHU this item includes a CPU board and I O modules mounted on VME baseboards, - The Motor Drive Electronic MDE , - The Crew panel Interface CPI , The Rack Interface Unit RIU...