Peter Shames | Jet Propulsion Laboratory, California Institute of Technology (original) (raw)

Papers by Peter Shames

Proceedings of the National Academy of Sciences, 1967

In the development of procedures for the calculation of polypeptide conformations, early work was... more In the development of procedures for the calculation of polypeptide conformations, early work was based on hard-sphere potentials.'-3 Subsequent calculations were made with more complete energy expressions.4' 6 At the same time, methods were explored for obtaining the conformation of minimum energy. In papers J6 and II7 of this series, Davidon's variable metric method8 was used to minimize the energies of straight-chain6 and cyclic7 polypeptide structures. In this method, gradients are computed, and all of the variables are permitted to change simultaneously. Since the multidimensional energy surface contains many local minima, it is advantageous to have a rapid procedure for minimizing the energy so that a large number of randomly selected starting points may be employed. Such a procedure is described in this paper, and applied to the calculation of the structure of gramicidin-S. Since an exhaustive search of all possible local minima has not been made, the structures reported here must be regarded as preliminary ones.

Data Analysis in Astronomy II, 1986

The international space community has begun to recognize that the established model for managemen... more The international space community has begun to recognize that the established model for management of communications with spacecraft -commanded data transmission over individual pair-wise contacts -is operationally unwieldy and will not scale in support of increasingly complex and sophisticated missions such as NASA's Constellation project. Accordingly, the international Inter-Agency Operations Advisory Group (IOAG) i chartered a Space Internetworking Strategy Group (SISG), which released its initial recommendations in a November 2008 report. The report includes a recommendation that the space flight community adopt Delay-Tolerant Networking (DTN) to address the problem of interoperability and communication scaling, especially in mission environments where there are multiple spacecraft operating in concert. This paper explores some of the issues that must be addressed in implementing, deploying, and operating DTN as part of a multi-mission, multi-agency space internetwork as well as benefits and future operational scenarios afforded by DTN-based space internetworking.

This CCSDS paper presents a reference architecture and service framework for spacecraft monitorin... more This CCSDS paper presents a reference architecture and service framework for spacecraft monitoring ... Mission Operations and Information Management Systems (MOIMS) area. ... In this context, Spacecraft Monitoring and Control (SM&C) refers to end-to-end services between ...

SpaceOps 2002 Conference, 2002

Spacecraft applications that interact with on-board sensors, effectors, and major components have... more Spacecraft applications that interact with on-board sensors, effectors, and major components have traditionally used private interfaces which are tightly bound to the interface details of the data links connecting these sub-systems. The latest spacecraft, which often include several powerful processors running real time operating systems, highspeed on-board networks, and intelligent peripherals, can support a more layered networked environment. Use of standard interfaces and networked elements is expected to yield reusable software and hardware components. Within CCSDS Panel 1K we have been developing such on-board interface standards. This paper will present a Message Transfer Service that defines a common API for use within a single spacecraft or among spacecraft flying in a constellation.

Acta Astronautica, 1995

JPL's Multimission Image Processing System (MIPS), is developed and maintained to meet requiremen... more JPL's Multimission Image Processing System (MIPS), is developed and maintained to meet requirements that span the NASA family of planetary missions. Remote access is provided via Internet to high performance Unix workstations, a large capacity mass storage subsystem, science instrument data processing and data management software, and photoprocessing services. Many Discovery principal investigators are finding that it would be cost effective to utilize this multimission facility with its established equipment, software, and interfaces with the telemetry processing system, to generate the first level data records for their instruments. This paper describes MIPS support to Mars Pathfinder as an example of the cost effective application of a multimission capability to reduce the cost of operations on a low-cost planetary mission.

INCOSE International Symposium, 2015

This paper presents a SysML pattern for modelling multi-layered interface architectures simply an... more This paper presents a SysML pattern for modelling multi-layered interface architectures simply and efficiently, in a way that supports expression of technical complexity, interfaces and behavior, and analysis of complexity. Each viewpoint and layer of abstraction has its own properties and behaviors. System elements are logically connected both horizontally along the communication path, and vertically across the different layers of protocols. The performance of upper layers depends on the performance of lower layers, yet the implementation of lower layers is intentionally opaque to upper layers. The system elements may not be linked directly at each horizontal layer but only via a some underlying communication path, and end-to-end communications may depend on intermediate components that are hidden from them, but may need to be shown in certain views and analyzed for certain purposes. This architectural model pattern uses methods described in ISO 42010, Recommended Practice for Architectural Description of Software-intensive Systems and CCSDS 311.0-M-1 [2], Reference Architecture for Space Data Systems (RASDS).

Space data systems are inherently complex. They are systems-of-systems, typically composed of spa... more Space data systems are inherently complex. They are systems-of-systems, typically composed of spacecraft and mission operations systems (MOS) belonging to one (or more) organizations, and multi-mission communication assets belonging to other organizations. In many cases, the spacecraft contain subsystems and instruments provided by different organizations, and MOS systems that may be developed and operated by other organizations. The point of greatest leverage in system architecting is at the interfaces. We have developed a set of methods for using SysML to model systems-of-systems and their interfaces. This paper describes how to apply this method to space data systems at a variety of levels of detail, from abstract systems and subsystems down to hardware and software components, including the details of their interfaces and protocol designs.

End-to-end space communication architectures must connect system elements that may be in space, o... more End-to-end space communication architectures must connect system elements that may be in space, on the ground in mission operations centers, or are shared assets such as ground communications stations. End-to-end connectivity involves space communications over RF links, but also cross support services, terrestrial network circuits, and a variety of application layer protocols for commanding, telemetry, and mission operations. CCSDS has developed a large suite of interoperable, and cross-supportable, protocols for these purposes. Each of these defines a specific " layer " of functionality, such as: RF modulation, space link error coding, cross support frame delivery, or network layer routing. CCSDS has recently published a Space Communication Cross Support Architecture Requirements Document (SCCS-ARD) that describes how many of these standards fit together and how they are intended to be used. This paper provides an overview of this document, presented so as to explain the concepts so that others may use them. These concepts will be described from several key viewpoints.

This architectural model pattern uses methods described in ISO 42010, Recommended Practice for Architectural Description of Software-intensive Systems and CCSDS 311.0-M-1 [2], Reference Architecture for Space Data Systems (RASDS).

In July 2001, the Space Domain Task Force of the Object Management Group (OMG) issued a Request f... more In July 2001, the Space Domain Task Force of the Object Management Group (OMG) issued a Request for Proposal (RFP) on Telemetric and Command Data Specification. This RFP solicited proposals that define telemetry and commanding data specifications in support of all phases of the satellite, payload, and ground segment lifecycle: system design, development, test, validation, and mission operations. In fact, telemetry and commanding data design is still often performed multiple times in multiple formats by multiple contractors during the lifecycle of the satellite, well before the satellite is ever deployed for mission operations. Standardisation of telemetry and commanding data descriptions for spacecraft health and safety monitoring, as well as payload interfaces, will reduce the cost of these implementations and decrease the development schedule, integration, and test of the satellite and its component systems. A common, adaptable specification can also be used to support multiple heterogeneous missions, facilitating interoperability among ground control systems, simulators, testing facilities, etc.

This paper describes an analytical approach and descriptive methodology that is adapted from Obje... more This paper describes an analytical approach and descriptive methodology that is adapted from Object-Oriented Analysis (OOA) techniques. The technique is described and then used to communicate key issues of system logical architecture. The essence of the approach is to limit the analysis to only service objects, with the idea of providing a direct mapping from the design to a client-server implementation. Key perspectives on the system, such as user interaction, data flow and management, service interfaces, hardware configuration, and system and data integrity are covered. A significant advantage of this service-oriented approach is that it permits mapping all of these different perspectives on the system onto a single common substrate. This services substrate is readily represented diagramatically, thus making details of the overall design much more accessible.

I NTROD UCTlO N lnteroperability of space data systems is of great concern to Space Agencies beca... more I NTROD UCTlO N lnteroperability of space data systems is of great concern to Space Agencies because sharing or reusing interoperable resources among multiple projects and multiple Agencies can reduce the cost of developing and operating space data systems. However, an on-going problem is that each space data system often has a different architecture and therefore the elements of one system cannot be easily used by other systems.

There recently have been a number significant effort to develop powerful and extensible approache... more There recently have been a number significant effort to develop powerful and extensible approaches for describing a general class of software intensive system architectures. These approaches are typically focused upon architectures of terrestrial systems and they range from generally applicable, but formalized, approaches like the System Engineering Modeling Language (SysML), to more focused approaches such as the Unified Modeling Language (UML) for RM-ODP (Reference Model for Open Distributed Processing).

The National Aeronautics and Space Administration (NASA) Space Communications and Navigation offi... more The National Aeronautics and Space Administration (NASA) Space Communications and Navigation office (SCaN) has commissioned a series of trade studies to define a new architecture intended to integrate the three existing networks that it operates, the Deep Space Network (DSN), Space Network (SN), and Near Earth Network (NEN), into one integrated network that offers users a set of common, standardized, services and interfaces. The integrated monitor and control architecture utilizes common software and common operator interfaces that can be deployed at all three network elements. This software uses state-of-the-art concepts such as a pool of re-programmable equipment that acts like a configurable software radio, distributed hierarchical control, and centralized management of the whole SCaN integrated network. For this trade space study a model-based approach using SysML was adopted to describe and analyze several possible options for the integrated network monitor and control architecture. This model was used to refine the design and to drive the costing of the four different software options. This trade study modeled the three existing self standing network elements at point of departure, and then described how to integrate them using variations of new and existing monitor and control system components for the different proposed deployments under consideration. This paper will describe the trade space explored, the selected system architecture, the modeling and trade study methods, and some observations on useful approaches to implementing such model based trade space representation and analysis.

Conference Presentations by Peter Shames

This is the presentation from the SpaceOps 2016 conference in Deajeon, Korea, May 2016. It is fo... more This is the presentation from the SpaceOps 2016 conference in Deajeon, Korea, May 2016. It is for the companion paper of the same title that describes the use of a SysML method for accurately modeling complex systems-of-system interfaces. The focus in this presentation is on the use of the method for modeling space systems interfaces, including system composition, services, data exchanges, protocol stacks, and protocol behaviors.

Proceedings of the National Academy of Sciences, 1967

Data Analysis in Astronomy II, 1986

SpaceOps 2002 Conference, 2002

Acta Astronautica, 1995

INCOSE International Symposium, 2015

This is the presentation from the SpaceOps 2016 conference in Deajeon, Korea, May 2016. It is fo... more This is the presentation from the SpaceOps 2016 conference in Deajeon, Korea, May 2016. It is for the companion paper of the same title that describes the use of CCSDS building blocks for constructing a variety of end-to-end space data systems architectures. It includes the following views: services, physical components, protocol stacks, and end-to-end deployments.