47 research outputs found
Event-Driven Network Model for Space Mission Optimization with High-Thrust and Low-Thrust Spacecraft
Numerous high-thrust and low-thrust space propulsion technologies have been
developed in the recent years with the goal of expanding space exploration
capabilities; however, designing and optimizing a multi-mission campaign with
both high-thrust and low-thrust propulsion options are challenging due to the
coupling between logistics mission design and trajectory evaluation.
Specifically, this computational burden arises because the deliverable mass
fraction (i.e., final-to-initial mass ratio) and time of flight for low-thrust
trajectories can can vary with the payload mass; thus, these trajectory metrics
cannot be evaluated separately from the campaign-level mission design. To
tackle this challenge, this paper develops a novel event-driven space logistics
network optimization approach using mixed-integer linear programming for space
campaign design. An example case of optimally designing a cislunar propellant
supply chain to support multiple lunar surface access missions is used to
demonstrate this new space logistics framework. The results are compared with
an existing stochastic combinatorial formulation developed for incorporating
low-thrust propulsion into space logistics design; our new approach provides
superior results in terms of cost as well as utilization of the vehicle fleet.
The event-driven space logistics network optimization method developed in this
paper can trade off cost, time, and technology in an automated manner to
optimally design space mission campaigns.Comment: 38 pages; 11 figures; Journal of Spacecraft and Rockets (Accepted);
previous version presented at the AAS/AIAA Astrodynamics Specialist
Conference, 201
Modeling and Optimization for Space Logistics Operations: Review of State of the Art
As "Space Mobility and Logistics" was listed as one of the five core
competencies in the US Space Force's doctrine document, there is a growing
interest in developing technologies to enable in-space refueling, servicing,
assembly, and manufacturing as well as other in-space logistics operations.
Modeling for space mobility and logistics requires a new approach that differs
from conventional astrodynamics because it needs to consider the coordination
of multiple vehicles to satisfy an overall demand; namely, the optimal
trajectory of one vehicle does not necessarily lead to the optimal campaign
solution that contains multiple vehicles and infrastructure elements. In
addition, for in-space servicing applications, we need additional analysis
capabilities to analyze and optimize the sizes of the fuel/spare depots and
their inventory/sparing policies with orbital mechanics in mind. To tackle
these challenges, there have been various attempts to leverage terrestrial
logistics-driven techniques, coupled with astrodynamics, to enhance in-space
operations; an earlier primary domain of interest was refueling and resource
utilization for human space exploration, and more recent studies focus on
in-space servicing, in-space manufacturing, and mega-scale constellations. This
paper aims to provide a review of the literature by categorizing the
state-of-the-art studies in two ways: (1) by application questions that are
addressed; and (2) by logistics-driven methods that are used in the studies.
The two categorizations are expected to help both practitioners and researchers
understand the state of the art and identify the under-explored and promising
future research directions.Comment: Submitted to AIAA SciTech Conference 202
Multidisciplinary Design Optimization Approach to Integrated Space Mission Planning and Spacecraft Design
© AIAASpace mission planning and spacecraft design are tightly coupled and need to be considered together for optimal performance; however, this integrated optimization problem results in a large-scale mixed-integer nonlinear programming (MINLP) problem, which is challenging to solve. In response to this challenge, this paper proposes a new solution approach to this problem based on decomposition-based optimization via augmented Lagrangian coordination. The proposed approach leverages the unique structure of the problem that enables its decomposition into a set of coupled subproblems of different types: a mixed-integer quadratic programming (MIQP) subproblem for mission planning, and one or more nonlinear programming (NLP) subproblem(s) for spacecraft design. Because specialized MIQP or NLP solvers can be applied to each subproblem, the proposed approach can efficiently solve the otherwise intractable integrated MINLP problem. An automatic and effective method to find an initial solution for this iterative approach is also proposed so that the optimization can be performed without a user-defined initial guess. The demonstration case study shows that, compared to the state-of-the-art method, the proposed formulation converges substantially faster and the converged solution is at least the same or better given the same computational time limit.This material is based upon work supported by the National Science Foundation under Grant No. 1942559
Cislunar Satellite Constellation Design Via Integer Linear Programming
Cislunar space awareness is of increasing interest to the international
community as Earth-Moon traffic is projected to increase. This raises the
problem of placing satellites optimally in a constellation to provide
satisfactory coverage for said traffic. The Circular Restricted 3 Body Problem
(CR3BP) provides promising periodic orbits in the Earth-Moon rotating frame for
traffic monitoring. This work converts a spatially and temporally varying
traffic coverage requirement into an integer linear programming problem,
attempting to minimize the number of satellites required for the requested
coverage.Comment: 18 pages, 15 figures, submitted to 2023 AAS Conferenc
Satellite Constellation Pattern Optimization for Complex Regional Coverage
The use of regional coverage satellite constellations is on the rise, urging
the need for an optimal constellation design method for complex regional
coverage. Traditional constellations are often designed for continuous global
coverage, and the few existing regional constellation design methods lead to
suboptimal solutions for periodically time-varying or spatially-varying
regional coverage requirements. This paper introduces a new general approach to
design an optimal constellation pattern that satisfies such complex regional
coverage requirements. To this end, the circular convolution nature of the
repeating ground track orbit and common ground track constellation is
formalized. This formulation enables a scalable constellation pattern analysis
for multiple target areas and with multiple sub-constellations. The formalized
circular convolution relationship is first used to derive a baseline
constellation pattern design method with the conventional assumption of
symmetry. Next, a novel method based on binary integer linear programming is
developed, which aims to optimally design a constellation pattern with the
minimum number of satellites. This binary integer linear programming method is
shown to achieve optimal constellation patterns for general problem settings
that the baseline method cannot achieve. Five illustrative examples are
analyzed to demonstrate the value of the proposed new approach.Comment: 47 pages, 23 figures, Journal of Spacecraft and Rockets (Published
Multi-Fidelity Space Mission Planning and Infrastructure Design Framework for Space Resource Logistics
To build a sustainable and affordable space transportation system for human
space exploration, the design and deployment of space infrastructures are
critical; one attractive and promising infrastructure system is the in-situ
resource utilization (ISRU) system. The design analysis and trade studies for
ISRU systems require the consideration of not only the design of the ISRU plant
itself but also other infrastructure systems (e.g., storage, power) and various
ISRU architecture options (e.g., resource, location, technology). This paper
proposes a system-level space infrastructure and its logistics design
optimization framework to perform architecture trade studies. A new space
infrastructure logistics optimization problem formulation is proposed that
considers infrastructure subsystems' internal interactions and their external
synergistic effects with space logistics simultaneously. Since the full-size
version of this proposed problem formulation can be computationally
prohibitive, a new multi-fidelity optimization formulation is developed by
varying the granularity of the commodity type definition over the network
graph; this multi-fidelity formulation can find an approximation solution to
the full-size problem computationally efficiently with little sacrifice in the
solution quality. The proposed problem formulation and method are applied to a
multi-mission lunar exploration campaign to demonstrate their values.Comment: 34 pages, 3 figures, presented at the AIAA Propulsion and Energy
Forum 2019, submitted to the Journal of Spacecraft and Rocket
Earth-Mars transfers through Moon distant retrograde orbits
This paper focuses on trajectory design which is relevant for missions that would follow NASA’s Asteroid Redirect Mission (ARM) to further explore and utilise asteroids and eventually human Mars exploration. Assuming that a refueling gas station is present at a given Lunar Distant Retrograde Orbit (DRO), we analyse ways of departing from the Earth to Mars via that DRO. Thus, the analysis and results presented in this paper add a new cis-lunar departure orbit for Earth-Mars missions. Porkchop plots depicting the required C3 at launch, v1 at arrival, Time of Flight (TOF), and total ∆V for various DRO departure and Mars arrival dates are created and compared with results obtained for low ∆V LEO to Mars trajectories. The results show that low ∆V DRO to Mars transfers generally have lower ∆V and TOF than LEO to Mars maneuvers
An Independent Assessment of the Technical Feasibility of the Mars One Mission Plan
In mid-2012, the Mars One program was announced, aiming to build the first human settlement on the surface of Mars. Following a series of precursor missions to develop and deploy key technologies, the first crewed mission would depart Earth in 2024, sending four people on a one-way journey to the surface of Mars. Additional four-person crews would be sent to Mars at every subsequent launch opportunity to further support and expand the Martian colony. While this program has been received with great fanfare, very little has been published in the technical literature on this mission architecture. As the Mars One mission plan represents a dramatic departure from more conservative exploration approaches, there are many uncertainties in the mission design. The establishment of a colony on Mars will rely on in-situ resource utilization (ISRU) and life support technologies that are more capable than the current state of the art. Moreover, resupply logistics and sparing will play a large role in the proposed colony, though the magnitude and behavior of these two effects is not well understood. In light of this, we develop a Mars settlement analysis tool that integrates a habitat simulation with an ISRU sizing model and a sparing analysis. A logistics model is utilized to predict the required number of launchers and provide a preliminary estimate of a portion of the program cost. We leverage this tool to perform an independent assessment of the technical feasibility of the Mars One mission architecture. Our assessment revealed a number of insights into architecture decisions for establishing a colony on the Martian surface. If crops are used as the sole food source, they will produce unsafe oxygen levels in the habitat. Furthermore, the ISRU system mass estimate is 8% of the mass of the resources it would produce over a two year period. That being said, the ISRU technology required to produce nitrogen, oxygen, and water on the surface of Mars is at a relatively low Technology Readiness Level (TRL), so such findings are preliminary at best. A spare parts analysis revealed that spare parts quickly come to dominate resupply mass as the settlement grows: after 130 months on the Martian surface, spare parts compose 62% of the mass brought from Earth to the Martian surface. The space logistics analysis revealed that, for the best scenario considered, establishing the first crew for a Mars settlement will require approximately 15 Falcon Heavy launchers and require $4.5 billion in funding, and these numbers will grow with additional crews. It is important to note that these numbers are derived only when considering the launch of life support and ISRU systems with spare parts. To capture a more realistic estimate of mission cost, future work should consider development and operations costs, as well as the integration of other key mission elements, such as communications and power systems. Technology development towards improving the reliability of life support systems, the TRL of ISRU systems, and the capability of Mars in-situ manufacturing will have a significant impact on reducing the mass and cost of Mars settlement architectures.United States. National Aeronautics and Space Administration (Grant NNX13AL76H)United States. National Aeronautics and Space Administration (Grant NNX14AM42H)Josephine De Karman Fellowship Trus