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Erica Gralla

The George Washington University, Engineering Management and Systems Engineering, Faculty Member

Massachusetts Institute of Technology (MIT), Engineering Systems Division (ESD), Research Affiliate

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Delft University of Technology

Matthieu Lauras

van Buul-Besseling

Marc van den Homberg

Delft University of Technology

Bruce Goldstein

University of Colorado, Boulder

Université de Technologie de Troyes (UTT)

Maarten van der Veen

Independent Researcher

Johnny Hartz Søraker

University of Twente

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Papers by Erica Gralla

Understanding the information needs of field-based decision-makers in humanitarian response to sudden onset disasters

The development and spread of new technology and the internet has opened a new world of possibili... more The development and spread of new technology and the internet has opened a new world of possibilities to gather data and create information in a crisis. However, it is not clear which information field managers require to make the best possible decisions. As a result, it is difficult for volunteers, technology developers, and others, to collect and analyze data that results in information that is accessible and actionable for decision makers. To understand the information requirements of humanitarian responders, a workshop was conducted, bringing together eighteen experienced humanitarian responders. The results of the workshop include preliminary frameworks for decisions and information requirements that are common during the initial phases of a sudden onset disaster. These frameworks will help volunteer and technical communities to understand the information field decision-makers require to make the best possible decisions.

Case study of a humanitarian logistics simulation exercise and insights for training design

Journal of Humanitarian Logistics and Supply Chain Management, 2015

Low Earth orbit constellation design using the Earth-Moon L1 point

Over the last decade, there has been a growing interest in the development of low earth orbit (LE... more Over the last decade, there has been a growing interest in the development of low earth orbit (LEO) microsatellite constellations for commercial, strategic, and scientific purposes. High costs present a major obstacle to the development of such constellations; launch costs, in particular, may represent as much as 40% of the life-cycle cost. Deployment of satellites into different orbital planes generally requires separate launch vehicles, so several smaller launches are required for a single constellation. We propose to reduce costs by using a single large launch vehicle to carry an entire fleet of microsatellites to the Earth-Moon L1 Lagrange point. By taking advantage of the complex dynamical behavior at this location, the microsatellites can be returned to multiple Earth orbital planes via aerocapture, using minimal ΔV. This paper presents a proof of concept and feasibility assessment of such a system, demonstrating 38% cost savings for a baseline mission.

Autonomous Logistics Technologies for Space Exploration: Experiment Results and Design Considerations

SpaceOps 2006 Conference, 2006

The ability to autonomously track and manage assets in space or at a planetary exploration site h... more The ability to autonomously track and manage assets in space or at a planetary exploration site holds the potential to greatly improve multiple aspects of space missions. At the International Space Station (ISS) everything from food and clothing to tools and experiments is currently managed manually or tracked using simple bar-coding techniques, often at the expense of time and accuracy. An autonomous system, based on radio-frequency identification (RFID) or related technologies, could save precious time, increase planning accuracy, increase safety, and even amplify science returns for extended exploration missions. However, these benefits must be weighed against overall system complexity, mass, and other issues such as ease-of-use and astronaut training. Such trades hinge on the requirements for the system in question: What technologies can and should be used? What kinds of applications should be included? At what level should assets be tracked? Suitable answers to these kinds of questions demand actual hardware/software development and field-testing.

<title>The New Worlds Observer: a mission for high-resolution spectroscopy of extra-solar terrestrial planets</title>

Optical, Infrared, and Millimeter Space Telescopes, 2004

The New Worlds Observer (NWO) is a proposed space mission to provide high resolution spectroscopy... more The New Worlds Observer (NWO) is a proposed space mission to provide high resolution spectroscopy from the far UV to the near IR of extra-solar terrestrial sized planets. The design of NWO is based on the concept of a large, space-based, pinhole camera made up of two spacecraft flying in formation. The first spacecraft is a large, thin occulting shield (perhaps hundreds of meters in diameter) with a shaped "pinhole" aperture about 10m in diameter. The second spacecraft is a conventional-quality space telescope (possibly with a 10m primary mirror) which "flies" through the pinhole image of the planetary system to observe the extra-solar planets free from stellar background. In this paper we describe the design of the two spacecraft system. In particular, the shaped-pinhole design utilizes the shaped-pupil coronagraph pioneered for the Terrestrial Planet Finder. In this paper we describe some of the NWO's technology challenges and science opportunities. Additionally, we describe an extension of the design to provide 100km resolution images of extra-solar planets.

A Modeling Framework for Interplanetary Supply Chains

Space 2006, 2006

As NASA looks ahead to next-generation human space exploration, it is essential to consider the c... more As NASA looks ahead to next-generation human space exploration, it is essential to consider the cost of operations and support in order to ensure the development of affordable programs. The life-cycle costs of future exploration ventures can be reduced by focusing on the interplanetary logistics strategy. By leveraging proven supply chain management techniques from the military and commercial sectors and applying them to the unique challenges of human space exploration, space logistics can be streamlined, and mission affordability and robustness can be increased. This paper describes a modeling framework for space logistics which enables description, evaluation, and optimization of various types of logistics strategies. The framework is embodied in SpaceNet, a discrete event simulation and optimization software program.

Logistics Information Systems for Human Space Exploration

SpaceOps 2006 Conference, 2006

Space agencies around the world are gearing up for new human space exploration missions. In order... more Space agencies around the world are gearing up for new human space exploration missions. In order to ensure that such programs are sustainable, it is worthwhile to examine the lessons learned from past experiences with space logistics and supply chain management. This paper offers an overview of the current state of the art in logistics management for space exploration focused on information systems, and highlights some emerging technologies that have the potential to significantly improve both the study and operation of space logistics systems.

Remote Terrestrial Sites as Operational/Logistics Analogs for Moon/Mars Bases: The Haughton Mars Project

by Erica Gralla and Sarah Shull

SpaceOps 2006 Conference, 2006

Mission planners for future human space exploration enterprises face several challenges in the ar... more Mission planners for future human space exploration enterprises face several challenges in the area of operations, including coordinating the logistics and resupply of far-flung planetary bases. A number of logistics methods have been perfected by commercial and military experts, but these are not well understood in the context of space exploration. This paper describes a field expedition to a Mars analog site in the high Arctic, at which terrestrial logistics methods were tested in the context of (analog) planetary exploration. A comprehensive comparison is drawn between the logistics scenarios at HMP and a potential lunar or Mars base, in order to determine the extent of the analogy between them. It appears that the analogy is quite good in certain categories of supplies and shipment, but breaks down in others. When certain straightforward differences are accounted for, the data gathered from HMP can be used to validate and inform planetary base logistics models in support of future human lunar and Mars exploration.

Optimal Launch Vehicle Size Determination for Moon-Mars Transportation Architectures

Space 2005, 2005

NASA's human Lunar and Mars exploration (HLE/HME) program requires a sustainable and affordable t... more NASA's human Lunar and Mars exploration (HLE/HME) program requires a sustainable and affordable transportation system between Earth and Moon/Mars. A crucial element of this system is the launch vehicle. Much debate has centered on the trade between expendable launch vehicles and heavy-lifters; however, arguments to date have been largely qualitative or limited in scope. This paper provides a quantitative enumeration of the launch vehicle trade space (in terms of both cost and risk), based on a generalizable process for generating launch manifests from transportation architectures (sets of vehicles for carrying out Lunar/Mars missions). For the baseline HLE/HME architecture considered here, an optimal launch vehicle size is found at approximately 82 metric tons; a 28-mt EELV emerges as another good option. The results show optimal launch vehicle selection is highly dependent on the transportation architecture. Therefore, launch vehicle selection should be considered an integral part of the design of the Moon/Mars exploration transportation system.

Assessing Trade-offs among Multiple Objectives for Humanitarian Aid Delivery Using Expert Preferences

Production and Operations Management, 2014

ABSTRACT Humanitarian aid agencies deliver emergency supplies and services to people affected by ... more ABSTRACT Humanitarian aid agencies deliver emergency supplies and services to people affected by disasters. Scholars and practitioners have developed modeling approaches to support aid delivery planning, but they have used objective functions with little validation as to the trade-offs among the multiple goals of aid delivery. We develop a method to value the performance of aid delivery plans, based on expert preferences over five key attributes: the amount of cargo delivered, the prioritization of aid by commodity type, the prioritization of aid by delivery location, the speed of delivery, and the operational cost. Through a conjoint analysis survey, we measure the preferences of 18 experienced humanitarian logisticians. The survey results quantify the importance of each attribute and enable the development of a piecewise linear utility function that can be used as an objective function in optimization models. The results show that the amount of cargo delivered is the most valued objective and cost the least important. Additionally, experts prioritize more vulnerable communities and more critical commodities, but not to the exclusion of others. With these insights and the experts’ utility functions, better humanitarian objective functions can be developed to enable better aid delivery in emergency response. This article is protected by copyright. All rights reserved.

The Future of Asset Management for Human Space Exploration: Supply Classification and an Integrated Database

by Robert Shishko, Sarah Shull, and Erica Gralla

Space 2006, 2006

One of the major logistical challenges in human space exploration is asset management. This paper... more One of the major logistical challenges in human space exploration is asset management. This paper presents observations on the practice of asset management in support of human space flight to date and discusses a functional-based supply classification and a framework for an integrated database that could be used to improve asset management and logistics for human missions to the Moon, Mars and beyond.

Understanding the information needs of field-based decision-makers in humanitarian response to sudden onset disasters

The development and spread of new technology and the internet has opened a new world of possibili... more The development and spread of new technology and the internet has opened a new world of possibilities to gather data and create information in a crisis. However, it is not clear which information field managers require to make the best possible decisions. As a result, it is difficult for volunteers, technology developers, and others, to collect and analyze data that results in information that is accessible and actionable for decision makers. To understand the information requirements of humanitarian responders, a workshop was conducted, bringing together eighteen experienced humanitarian responders. The results of the workshop include preliminary frameworks for decisions and information requirements that are common during the initial phases of a sudden onset disaster. These frameworks will help volunteer and technical communities to understand the information field decision-makers require to make the best possible decisions.

Case study of a humanitarian logistics simulation exercise and insights for training design

Journal of Humanitarian Logistics and Supply Chain Management, 2015

Low Earth orbit constellation design using the Earth-Moon L1 point

Over the last decade, there has been a growing interest in the development of low earth orbit (LE... more Over the last decade, there has been a growing interest in the development of low earth orbit (LEO) microsatellite constellations for commercial, strategic, and scientific purposes. High costs present a major obstacle to the development of such constellations; launch costs, in particular, may represent as much as 40% of the life-cycle cost. Deployment of satellites into different orbital planes generally requires separate launch vehicles, so several smaller launches are required for a single constellation. We propose to reduce costs by using a single large launch vehicle to carry an entire fleet of microsatellites to the Earth-Moon L1 Lagrange point. By taking advantage of the complex dynamical behavior at this location, the microsatellites can be returned to multiple Earth orbital planes via aerocapture, using minimal ΔV. This paper presents a proof of concept and feasibility assessment of such a system, demonstrating 38% cost savings for a baseline mission.

Autonomous Logistics Technologies for Space Exploration: Experiment Results and Design Considerations

SpaceOps 2006 Conference, 2006

The ability to autonomously track and manage assets in space or at a planetary exploration site h... more The ability to autonomously track and manage assets in space or at a planetary exploration site holds the potential to greatly improve multiple aspects of space missions. At the International Space Station (ISS) everything from food and clothing to tools and experiments is currently managed manually or tracked using simple bar-coding techniques, often at the expense of time and accuracy. An autonomous system, based on radio-frequency identification (RFID) or related technologies, could save precious time, increase planning accuracy, increase safety, and even amplify science returns for extended exploration missions. However, these benefits must be weighed against overall system complexity, mass, and other issues such as ease-of-use and astronaut training. Such trades hinge on the requirements for the system in question: What technologies can and should be used? What kinds of applications should be included? At what level should assets be tracked? Suitable answers to these kinds of questions demand actual hardware/software development and field-testing.

<title>The New Worlds Observer: a mission for high-resolution spectroscopy of extra-solar terrestrial planets</title>

Optical, Infrared, and Millimeter Space Telescopes, 2004

The New Worlds Observer (NWO) is a proposed space mission to provide high resolution spectroscopy... more The New Worlds Observer (NWO) is a proposed space mission to provide high resolution spectroscopy from the far UV to the near IR of extra-solar terrestrial sized planets. The design of NWO is based on the concept of a large, space-based, pinhole camera made up of two spacecraft flying in formation. The first spacecraft is a large, thin occulting shield (perhaps hundreds of meters in diameter) with a shaped "pinhole" aperture about 10m in diameter. The second spacecraft is a conventional-quality space telescope (possibly with a 10m primary mirror) which "flies" through the pinhole image of the planetary system to observe the extra-solar planets free from stellar background. In this paper we describe the design of the two spacecraft system. In particular, the shaped-pinhole design utilizes the shaped-pupil coronagraph pioneered for the Terrestrial Planet Finder. In this paper we describe some of the NWO's technology challenges and science opportunities. Additionally, we describe an extension of the design to provide 100km resolution images of extra-solar planets.

A Modeling Framework for Interplanetary Supply Chains

Space 2006, 2006

As NASA looks ahead to next-generation human space exploration, it is essential to consider the c... more As NASA looks ahead to next-generation human space exploration, it is essential to consider the cost of operations and support in order to ensure the development of affordable programs. The life-cycle costs of future exploration ventures can be reduced by focusing on the interplanetary logistics strategy. By leveraging proven supply chain management techniques from the military and commercial sectors and applying them to the unique challenges of human space exploration, space logistics can be streamlined, and mission affordability and robustness can be increased. This paper describes a modeling framework for space logistics which enables description, evaluation, and optimization of various types of logistics strategies. The framework is embodied in SpaceNet, a discrete event simulation and optimization software program.

Logistics Information Systems for Human Space Exploration

SpaceOps 2006 Conference, 2006

Space agencies around the world are gearing up for new human space exploration missions. In order... more Space agencies around the world are gearing up for new human space exploration missions. In order to ensure that such programs are sustainable, it is worthwhile to examine the lessons learned from past experiences with space logistics and supply chain management. This paper offers an overview of the current state of the art in logistics management for space exploration focused on information systems, and highlights some emerging technologies that have the potential to significantly improve both the study and operation of space logistics systems.

Remote Terrestrial Sites as Operational/Logistics Analogs for Moon/Mars Bases: The Haughton Mars Project

by Erica Gralla and Sarah Shull

SpaceOps 2006 Conference, 2006

Mission planners for future human space exploration enterprises face several challenges in the ar... more Mission planners for future human space exploration enterprises face several challenges in the area of operations, including coordinating the logistics and resupply of far-flung planetary bases. A number of logistics methods have been perfected by commercial and military experts, but these are not well understood in the context of space exploration. This paper describes a field expedition to a Mars analog site in the high Arctic, at which terrestrial logistics methods were tested in the context of (analog) planetary exploration. A comprehensive comparison is drawn between the logistics scenarios at HMP and a potential lunar or Mars base, in order to determine the extent of the analogy between them. It appears that the analogy is quite good in certain categories of supplies and shipment, but breaks down in others. When certain straightforward differences are accounted for, the data gathered from HMP can be used to validate and inform planetary base logistics models in support of future human lunar and Mars exploration.

Optimal Launch Vehicle Size Determination for Moon-Mars Transportation Architectures

Space 2005, 2005

NASA's human Lunar and Mars exploration (HLE/HME) program requires a sustainable and affordable t... more NASA's human Lunar and Mars exploration (HLE/HME) program requires a sustainable and affordable transportation system between Earth and Moon/Mars. A crucial element of this system is the launch vehicle. Much debate has centered on the trade between expendable launch vehicles and heavy-lifters; however, arguments to date have been largely qualitative or limited in scope. This paper provides a quantitative enumeration of the launch vehicle trade space (in terms of both cost and risk), based on a generalizable process for generating launch manifests from transportation architectures (sets of vehicles for carrying out Lunar/Mars missions). For the baseline HLE/HME architecture considered here, an optimal launch vehicle size is found at approximately 82 metric tons; a 28-mt EELV emerges as another good option. The results show optimal launch vehicle selection is highly dependent on the transportation architecture. Therefore, launch vehicle selection should be considered an integral part of the design of the Moon/Mars exploration transportation system.

Assessing Trade-offs among Multiple Objectives for Humanitarian Aid Delivery Using Expert Preferences

Production and Operations Management, 2014

ABSTRACT Humanitarian aid agencies deliver emergency supplies and services to people affected by ... more ABSTRACT Humanitarian aid agencies deliver emergency supplies and services to people affected by disasters. Scholars and practitioners have developed modeling approaches to support aid delivery planning, but they have used objective functions with little validation as to the trade-offs among the multiple goals of aid delivery. We develop a method to value the performance of aid delivery plans, based on expert preferences over five key attributes: the amount of cargo delivered, the prioritization of aid by commodity type, the prioritization of aid by delivery location, the speed of delivery, and the operational cost. Through a conjoint analysis survey, we measure the preferences of 18 experienced humanitarian logisticians. The survey results quantify the importance of each attribute and enable the development of a piecewise linear utility function that can be used as an objective function in optimization models. The results show that the amount of cargo delivered is the most valued objective and cost the least important. Additionally, experts prioritize more vulnerable communities and more critical commodities, but not to the exclusion of others. With these insights and the experts’ utility functions, better humanitarian objective functions can be developed to enable better aid delivery in emergency response. This article is protected by copyright. All rights reserved.

The Future of Asset Management for Human Space Exploration: Supply Classification and an Integrated Database

by Robert Shishko, Sarah Shull, and Erica Gralla

Space 2006, 2006

One of the major logistical challenges in human space exploration is asset management. This paper... more One of the major logistical challenges in human space exploration is asset management. This paper presents observations on the practice of asset management in support of human space flight to date and discusses a functional-based supply classification and a framework for an integrated database that could be used to improve asset management and logistics for human missions to the Moon, Mars and beyond.