
Robert ShishkoCalifornia Institute of Technology | CIT · Jet Propulsion Laboratory
Robert Shishko
Doctor of Philosophy
About
55
Publications
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1,287
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Introduction
Additional affiliations
August 1983 - present
Publications
Publications (55)
The 2033 Mars launch period provides a unique opportunity for a round-trip mission with a total flight time of only 1.6 years. A concept is presented to perform a crewed Mars orbital mission in 2033 that would minimize development and mission risk by using conventional hypergolic in-space propulsion stages with a common design. The Mars mission veh...
This paper reports on our effort to develop an ensemble of specialized models to explore the commercial potential of mining water/ice on Mars in support of a Mars Colony. This ensemble starts with a formal systems architecting framework to describe a Mars Colony and capture its artifacts' parameters and technical attributes. The resulting database...
This paper develops a network optimization formulation for dynamic campaign-level space mission planning. Although many past space missions have been designed mainly from a mission-level perspective, a campaign-level perspective will be important for future space exploration. In order to find the optimal campaign-level space transportation architec...
Simple logistics strategies such as "carry-along" and Earth-based "resupply" were sufficient for past human space programs. Next-generation space logistics paradigms are expected to be more complex, involving multiple exploration destinations and in-situ resource utilization (ISRU). Optional ISRU brings additional complexity to the interplanetary s...
The aim of this effort is to develop an integrated set of risk-based financial and technical models to evaluate multiple Off-Earth Mining (OEM) scenarios. This quantitative, scenario-and simulation-based tool will help identify combinations of market variables, technical parameters, and policy levers that will enable the expansion of the global eco...
This research develops a dynamic logistics network formulation for lifecycle optimization of mission sequences as a system-level integrated method to find an optimal combination of technologies to be used at each stage of the campaign. This formulation can find the optimal transportation architecture considering its technology trades over time. The...
This paper introduces a novel dynamic modeling formulation for spaceflight logistics network. The formulation is based on dynamic extension of Generalized Multi-Commodity Network Flow (GMCNF) formulation and enables optimization of campaign-level spaceflight logistics using linear programming. A time-expanded network is used for multi-period modeli...
In transition to a new era of human space exploration, the question is what the next- generation space logistics paradigm should be. The past studies on space logistics have been mainly focused on a "vehicle" perspective such as propulsive feasibility, cargo capacity constraints, and manifesting strategies, with the arbitrarily predetermined logist...
Operations and support (O&S) costs for human spaceflight have not received the same attention in the cost estimating community as have development costs. This is unfortunate as O&S costs typically comprise a majority of life-cycle costs (LCC) in such programs as the International Space Station (ISS) and the now-cancelled Constellation Program. Reco...
In transition to a new era of space exploration, the question is what the next space logistics paradigm should be. The past studies on space logistics have been mainly focused on a “vehicle” perspective such as propulsive feasibility, cargo capacity constraints, manifesting strategies, and crew and vehicle demand, all assuming a predefined logistic...
Due to the highly constrained schedules and budgets that NASA missions must contend with, the identification and management of cost, schedule and risks in the earliest stages of the lifecycle is critical. At the Jet Propulsion Laboratory, it is the concurrent engineering teams that first address these items in a systematic manner. Foremost of these...
The Defense Advanced Research Projects Agency (DARPA) has recently begun an effort to further refine its Fractionated Spacecraft vision. This vision (called the "F6" program) seeks to explore distributed spacecraft architectures capable of performing complex functions similar to current monolithic spacecrafts. However, the ability of fractionated s...
This paper summarizes the motivation for and the resulting development of a flexible
object-oriented software model for simulation and analysis of space exploration campaign
logistics. The software model was designed to be applicable to several widely-varying use
case scenarios including International Space Station resupply, support for a long-term...
A new method for analyzing margins in the Constellation program is described and applied to the performance and mass margins for the integrated transportation system returning humans to the lunar surface. The approach treats the Ares-V Earth-departure-stage gross payload-delivery capability and the translunar injection masses of Orion and Altair as...
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 logi...
Developments in architectural frameworks and system-of-systems thinking have provided useful constructs for systems engineering. DoDAF concepts, language, and formalisms, in particular, provide a natural way of conceptualizing an operations cost model applicable to NASA's space exploration vision. Not all DoDAF products have meaning or apply to a D...
Massachusetts Institute of Technology. Dept. of Political Science. Thesis. 1968. B.S. (Also B.S. in Economics). Sixteen unnumbered leaves inserted. Co-author: Jeffrey Raffel. Bibliography: â. 82. B.S.(Also B.S.in Economics).
*The analogy approach in cost estimation combines actual cost data from similar existing systems, activiti es, or items with adjustments for a new project’s technical, physical or programmatic differences to derive a cost estimate for the new system. This method is normally used early in a project cycle when there is insufficient design/cost data t...
A long-standing problem in NASA is how to allocate scarce technology development resources across advanced technologies in order to best support a large set of future potential missions. Within NASA, two (orthogonal) paradigms have received attention in recent years: the real-options approach and the broad mission model approach. This paper focuses...
A Project Trades Model (PTM) is a collection of tools/simulations linked together to rapidly perform integrated system trade studies of performance, cost, risk, and mission effectiveness. An operating PTM captures the interactions between various targeted systems and subsystems through an exchange of computed variables of the constituent models. Se...
Advancement of critical technologies is a key factor in enabling future space missions. Yet, there is clearly a mismatch between the available funding and the cost of pursuing all technologies that have been identified as critical. Therefore, a process is needed to select the technologies that can provide the highest return on investment. In this p...
In November 2001, the Iss Management and Cost Evaluation (IMCE) Task Force found that the imposition of annual budget caps was counterproductive to controlling total Space Station lifvcle costs. Program management focus on annual budgets has resulted today in signhcant cost overruns for the Space Station and the forfeiture of research opportunities...
We examine the use of real‐options valuation in the context of prioritizing advanced technologies for NASA funding. Further, we offer a set of computational procedures that quantifies the option value of each technology. Other researchers have applied a real‐options framework to private sector investments. In the case of NASA investments in advance...
On 4 July 1997, the Mars Pathfinder landed on the surface of Mars carrying the first planetary rover, known as the Sojourner. Formally known as the Microrover Flight Experiment (MFEX), the Sojourner was a low cost, high-risk technology demonstration, in which new risk management techniques were tried. This paper summarizes the activities and result...
This paper summarizes work in progress to define and implement a risk management process tailored to a low-cost, high-risk NASA mission–the Microrover Flight Experiment (MFEX, commonly called the Mars microrover). The tailored risk management process is described along with the extensive data collection, documentation, and quantitative analyses tha...
The design to cost concept establishes cost as a design parameter to be considered for a system throughout its life cycle. Cost is considered a design parameter equal in importance to technical requirements and schedule. Rockwell and the Jet Propulsion Laboratory have jointly learned that the most effective way to implement design to cost in our pr...
This handbook brings the fundamental concepts and techniques of systems
engineering to NASA personnel in a way that recognizes the nature of
NASA systems and environment. It is intended to accompany formal NASA
training courses on systems engineering and project management when
appropriate, and is designed to be a top-level overview. The concepts
w...
This handbook brings the fundamental concepts and techniques of systems engineering to NASA personnel in a way that recognizes the nature of NASA systems and environment. It is intended to accompany formal NASA training courses on systems engineering and project management when appropriate, and is designed to be a top-level overview. The concepts w...
When applied to a system, the doctrine of successive refinement is a
divide-and-conquer strategy. Complex systems are sucessively divided
into pieces that are less complex, until they are simple enough to be
conquered. This decomposition results in several structures for
describing the product system and the producing system. These structures
play...
The fundamental concepts and process of systems engineering as they apply in the context of the National Aeronautics and Space Administration are described. In particular: Systems and systems engineering are defined, and the objectives of systems engineering are discussed. The doctrine of successive refinement is presented, and the associated spira...
System Design Tradeoff Model (SDTM) computer program produces information which helps to enforce consistency of design objectives throughout system. Mathematical model of set of possible designs for Space Station Freedom. Program finds particular design enabling station to provide specified amounts of resources to users at lowest total (or life-cyc...
MESSOC (Model for Estimating Space Station Operations Costs) is the result of a multi-year effort by NASA to understand and model the mature operations cost of Space Station Freedom. This paper focuses on MESSOC's ability to contribute to life-cycle cost analyses through its logistics equations and databases. Together, these afford MESSOC the capab...
AURA (Army Unit Readiness/Sustainability Assessor) is a Monte Carlo event simulation model that permits decisionmakers to examine the implications of alternative resource levels on the output of combined arms units, and to assess a broad range of theater-wide resource allocation policies. This report describes AURA applications to the mission-gener...
AURA(Army Unit Readiness/Sustainability Assessor) is a Monte Carlo discrete-event computerized simulation model intended for analyzing the interrelations among the resources associated with a set of combat units, and the capability of those units to generate combat missions in a dynamic, rapidly evolving wartime environment. This volume is the seco...
As Soviet forces have modernized and increased in size over the past ten years, U.S. military commanders have become noticeably more concerned not only about sustaining U.S. qualitative superiority in the 1980s, but also about improving the readiness and sustainability of forces already in the field. Few analytical tools are available to help readi...
Results are presented of research on the choice of the discount rate for the evaluation of public projects. The need for discounting arises in the evaluation of both public and private projects because costs and benefits occurring in different years must be treated differently. While all serious economists believe that discounting is the correct wa...
We show that the pseudo empirical maximum likelihood estimator can be recast as a calibration estimator. The process of estimating the probabilities pk of the distribution function can be done also in a maximum entropy framework. We suggest that a minimum cross-entropy estimator has attractive theoretical properties. A Monte Carlo simulation sugges...
Much of the recent literature on the theory of games has focused on the contributions of that subject to problems of an economic nature. Several of these recent papers have attempted to bring together and compare a number of solution concepts relevant to a particular class of economic games. It is the primary purpose of this paper to present and el...
The report investigates the determinants of the aggregate supply function of moonlighting labor in terms of demographic and market factors. The Tobit model of limited dependent variables was used to estimate a moonlighting supply curve from data from the Income Dynamics Panel study. The elasticity of supply with respect to moonlighting wages was fo...
An application of location theory to the question of centralized versus decentralized library facilities for a university, with relevance for special libraries is presented. The analysis provides models for a single library, for two or more libraries, or for decentralized facilities. (6 references) (Author/NH)
This paper describes a cost-effectiveness study of the use of vertical or short takeoff and landing (VSTOL) aircraft for combat missions. A comparison is made with conventional (CTOL) aircraft as tactical fighters in a future NATO environment. The conditions under which VSTOL and CTOL aircraft can be considered to be competitive systems are careful...
A model is constructed to determine how much to put into a particular R and D program at any time. The problem is formulated in the following way: given a production function for technical change one seeks a path which maximizes the present discounted value of the difference between its benefits and costs. The model is developed within the context...
In this paper. we examine the use of real options valuation in the context of prioritizing advanced technologies for NASA funding. Further, we offer a set of computational procedures that quantifies the option value of each technology. Other researchers have applied a real options framework to private sector investments. In the case of NASA investm...