Selection, Technology Evaluation and Recommendations for Moon/Mars Transportation Architectures
- Paper number
IAC-05-A3.P.11
- Author
Mrs. Gergana Bounova, Massachussets Institute of Technology (MIT), United States
- Coauthor
Mr. Jaemyung Ahn, Massachussets Institute of Technology (MIT), United States
- Coauthor
Mr. Paul Wooster, Massachussets Institute of Technology (MIT), United States
- Coauthor
Dr. Rania Hassan, Massachussets Institute of Technology (MIT), United States
- Coauthor
Dr. Olivier de Weck, Massachussets Institute of Technology (MIT), United States
- Year
2005
- Abstract
Our purpose is to evaluate and select from a large family of Moon-Mars transportation architectures by integrating a general architecture network model with vehicle computational modules. Three Mars and five lunar architectures are downselected based on total launch mass to LEO and further criteria. Key findings and sensitivity analysis of mass for different advanced propulsion types and in-situ propellant production availability are presented.
Architecture Representation (OPN) and Integration Methodology
The Object Process Network (OPN) is a discrete event simulator, used to generate all possible operational sequences and associated hardware elements for space exploration missions. The output of OPN is a set of matrices representing 1162 architectures with modules and their operations. To integrate the matrix architecture description with explicit vehicle (subsystem) modules, the times of flight and delta Vs for each phase are calculated using additional trajectory computation tools. These provide options for Earth to Moon or Mars transfer with orbital or L1 rendezvous, and free return from destination for various propulsion types. The baseline analysis uses chemical propulsion. Payload, surface operations and technology options are also specified upfront.
Using the OPN matrix entries to specify flights and the trajectory modules, times of flight and delta Vs are calculated for each phase for each module, saved in matrices analogous to the OPN matrix. Thus the operational sequence for each vehicle is assembled. Habitat masses are calculated first, since they only depend on durations, and are independent of the rocket equation. Propulsion stage masses which are considered payload on other flights, like Trans-Earth-Injection, descent/ascent stages are calculated first. A propulsion stage mass is calculated only if its payload is already known. Detailed description of the masses integration process is available. The module integration provides an architecture description and evaluation for a given mission with total mass, vehicle and subsystem mass breakdown. The general nature of this method allows the rapid evaluation of thousands of architectures, performing different technology trades on them, downselecting and recommending architectures for the space exploration effort.
Technology Switches Analysis
The technology options in our analysis are different propulsion types, including chemical, electric propulsion with solar and nuclear power and nuclear thermal propulsion, the availability of In-Situ Propellant Production (ISPP) and different power options like batteries types, fuel cells and RTGs for each vehicle. These technology options are traded for missions with different crew size, payload and surface durations. The three selected Mars architectures, indexed 395, 881 and 969, will be described in detailed in our paper. They are compared for different advanced propulsion types with or without in-situ propellant production. Nuclear thermal propulsion clearly dominates the advanced propulsion options. Nuclear electric is dominated by solar electric, however solar electric probably has deployment challenges (>500 kW-e). For nuclear thermal or nuclear electric to be useful, reactor operation in Earth orbit is required. ISPP enables direct return (which provides lowest mission risk and highest crew safety), but would likely require surface nuclear power (order of 100 kW-e). Arch 969 provides lowest initial mass to LEO across all technology switches. Studies on Mars-Moon architecture and mission commonality to develop a sustainable extensible campaign for human space exploration are also available.
- Abstract document