Evolution of MPCV Service Module Propulsion and GN&C Interface Requirements between Constellation and European Service Module

Abstract

The Orion Multi-Purpose Crew Vehicle Service Module Propulsion Subsystem provides propulsion for the integrated Crew and Service Module. Updates in the exploration architecture between Constellation and MPCV as well as NASA's partnership with the European Space Agency have resulted in design changes to the SM Propulsion Subsystem and updates to the Propulsion interface requirements with Guidance Navigation and Control. This paper focuses on the Propulsion and GNC interface requirement updates between the Constellation Service Module and the European ServiceModule and how the requirement updates were driven or supported by architecture updates and the desired use of hardware with heritage to United States and European spacecraft for the Exploration Missions, EM-1 and EM-2.

Implementation of the Orbital Maneuvering System Engine and Thrust Vector Control for the European Service Module

“…The engine and TVC specifications are derived from the ESM propulsion subsystem technical specification which is a product of the applicable ESM system level requirements. These system level requirements were evolved from Constellation Program (CxP) Service Module requirements documents 3 .…”

Plume Impingement Analysis for the European Service Module Propulsion System

“…Similar efforts have been performed for the previous iteration of the Orion SM. 3,4 The ESM, however, incorporates a different design with the following highlighted changes: 5  Using the Shuttle heritage 26.7 kN (6000 lbf) 55:1 area ratio (AR) OMS-E instead of the 33.4 kN (7500 lbf) 150:1 AR Orion Main Engine 6  Using the HTV heritage 300:1 AR nozzle extension instead of a 164:1 AR for the auxiliary engines  Using 220 N (50 lbf) RCS engines instead of 110 N (25 lbf) RCS engines  Using four rectangular solar arrays instead of two circular Ultraflex arrays These differences, among several others including engine locations, required a new plume impingement analysis study to be performed. In particular, the simulation results are used to help optimize the RCS engine placement and configuration on the ESM as well as solar array placement and orientation for each burn profile to minimize risk of potential plume induced heat damage and contamination.…”