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Various issues associated with next generation Internet are presented in viewgraph form. Specific topics include: 1) Internet architecture; 2) NASA's advanced networking; 3) Internet capability, capacity and applications; and 4) Systems engineering.
The Satellite Networks and Architecture Branch has developed the In-Space Internet Node Technology testbed (ISINT) for investigating the use of commercial Internet products for NASA missions. The testbed connects two closed subnets over a tabletop Ka-band transponder by using commercial routers and modems. Since many NASA assets are in low Earth orbits (LEO's), the testbed simulates the varying signal strength, changing propagation delay, and varying connection times that are normally experienced when communicating to the Earth via a geosynchronous orbiting (GEO) communications satellite. Research results from using this testbed will be used to determine which Internet technologies are appropriate for NASA's future communication needs.
Currently there are two approaches to provide Quality of Service (QoS) in the next generation Internet: An early one is the Integrated Services (IntServ) with the goal of allowing end-to-end QoS to be provided to applications; the other one is the Differentiated Services (DiffServ) architecture providing QoS in the backbone. In this context, a DiffServ network may be viewed as a network element in the total end-to-end path. The objective of this paper is to investigate the possibility of providing end-to-end QoS when IntServ runs over DiffServ backbone in the next generation Internet. Our results show that the QoS requirements of IntServ applications can be successfully achieved when IntServ traffic is mapped to the DiffServ domain in next generation Internet.
How are scientists going to make use of the Internet several years from now? This is a case study of a leading-edge experiment in building a 'virtual institute'-- using electronic communication tools to foster collaboration among geographically dispersed scientists. Our experience suggests: Scientists will want to use web-based document management systems. There will be a demand for Internet-enabled meeting support tools. While internet videoconferencing will have limited value for scientists, webcams will be in great demand as a tool for transmitting pictures of objects and settings, rather than "talking heads." and a significant share of scientists who do fieldwork will embrace mobile voice, data and video communication tools. The setting for these findings is a research consortium called the NASA Astrobiology Institute.
3D graphics through the Internet needs to move beyond the current lowest common denominator of pre-computed movies, which consume bandwidth and are non-interactive. Panelists will demonstrate and compare 3D graphical tools for accessing, analyzing, and collaborating on information through the Internet and World-wide web. The "shoot-out" will illustrate which tools are likely to be the best for the various types of information, including dynamic scientific data, 3-D objects, and virtual environments. The goal of the panel is to encourage more effective use of the Internet by encouraging suppliers and users of information to adopt the next generation of graphical tools.
For the last several years the Science Directorate at Marshall Space Flight Center has carried out a diverse program of Internet-based science communication. The Directorate's Science Roundtable includes active researchers, NASA public relations, educators, and administrators. The Science@NASA award-winning family of Web sites features science, mathematics, and space news. The program includes extended stories about NASA science, a curriculum resource for teachers tied to national education standards, on-line activities for students, and webcasts of real-time events. The focus of sharing science activities in real-time has been to involve and excite students and the public about science. Events have involved meteor showers, solar eclipses, natural very low frequency radio emissions, and amateur balloon flights. In some cases, broadcasts accommodate active feedback and questions from Internet participants. Through these projects a pattern has emerged in the level of interest or popularity with the public. The pattern differentiates projects that include science from those that do not, All real-time, event-based Internet activities have captured public interest at a level not achieved through science stories or educator resource material exclusively. The worst event-based activity attracted more interest than the best written science story. One truly rewarding lesson learned through these projects is that the public recognizes the importance and excitement of being part of scientific discovery. Flying a camera to 100,000 feet altitude isn't as interesting to the public as searching for viable life-forms at these oxygen-poor altitudes. The details of these real-time, event-based projects and lessons learned will be discussed.
This paper presents work being done at NASA/GSFC (Goddard Space Flight Center) on applying standard Internet applications and protocols to meet the technology challenge of future satellite missions. Internet protocols (IP) can provide seamless dynamic communication among heterogeneous instruments, spacecraft, ground stations, and constellations of spacecraft. A primary component of this work is to design and demonstrate automated end-to-end transport of files in a dynamic space environment using off-the-shelf, low-cost, commodity-level standard applications and protocols. These functions and capabilities will become increasingly significant in the years to come as both Earth and space science missions fly more sensors and the present labor-intensive, mission-specific techniques for processing and routing data become prohibitively expensive. This paper describes how an IP-based communication architecture can support existing operations concepts and how it will enable some new and complex communication and science concepts. The authors identify specific end-to-end file transfers all the way from instruments to control centers and scientists, and then describe how each data flow can be supported using standard Internet protocols and applications. The scenarios include normal data downlink and command uplink as well as recovery scenarios for both onboard and ground failures. The scenarios are based on an Earth orbiting spacecraft with data rates and downlink capabilities from 300 Kbps to 4 Mbps. Many examples are based on designs currently being investigated for the Global Precipitation Measurement (GPM) mission.
Distribution of interactive multimedia to remote investigators will be required for high quality science on the International Space Station (ISS). The Internet with the World Wide Web (WWW) and the JAVA environment are a good match for distribution of data, video and voice to remote science centers. Utilizing the "open" Internet in a secure manner is the major hurdle in making use of this cost effective, off-the-shelf, universal resource. This paper examines the major security threats to an Internet distribution system for payload data and the mitigation of these threats. A proposed security environment for the Space Station Biological Research Facility (SSBRP) is presented with a short description of the tools that have been implemented or planned. Formulating and implementing a security policy, firewalls, host hardware and software security are also discussed in this paper. Security is a vast topic and this paper can only give an overview of important issues. This paper postulates that a structured approach is required and stresses that security must be built into a network from the start. Ignoring security issues or putting them off until late in the development cycle can be disastrous.
AZ Technology has been working with MSFC Ground Systems Department to find ways to make it easier for remote experimenters (RPI's) to monitor their International Space Station (ISS) payloads in real-time from anywhere using standard/familiar devices. AZ Technology was awarded an SBIR Phase I grant to research the technologies behind and advancements of distributing live ISS data across the Internet. That research resulted in a product called "EZStream" which is in use on several ISS-related projects. Although the initial implementation is geared toward ISS, the architecture and lessons learned are applicable to other space-related programs. This paper presents the high-level architecture and components that make up EZStream. A combination of commercial-off-the-shelf (COTS) and custom components were used and their interaction will be discussed. The server is powered by Apache's Jakarta-Tomcat web server/servlet engine. User accounts are maintained in a My SQL database. Both Tomcat and MySQL are Open Source products. When used for ISS, EZStream pulls the live data directly from NASA's Telescience Resource Kit (TReK) API. TReK parses the ISS data stream into individual measurement parameters and performs on-the- fly engineering unit conversion and range checking before passing the data to EZStream for distribution. TReK is provided by NASA at no charge to ISS experimenters. By using a combination of well established Open Source, NASA-supplied. and AZ Technology-developed components, operations using EZStream are robust and economical. Security over the Internet is a major concern on most space programs. This paper describes how EZStream provides for secure connection to and transmission of space- related data over the public Internet. Display pages that show sensitive data can be placed under access control by EZStream. Users are required to login before being allowed to pull up those web pages. To enhance security, the EZStream client/server data transmissions can be encrypted to preclude interception. EZStream was developed to make use of a host of standard platforms and protocols. Each are discussed in detail in this paper. The I3ZStream server is written as Java Servlets. This allows different platforms (i.e. Windows, Unix, Linux . Mac) to host the server portion. The EZStream client component is written in two different flavors: JavaBean and ActiveX. The JavaBean component is used to develop Java Applet displays. The ActiveX component is used for developing ActiveX-based displays. Remote user devices will be covered including web browsers on PC#s and scaled-down displays for PDA's and smart cell phones. As mentioned. the interaction between EZStream (web/data server) and TReK (data source) will be covered as related to ISS. EZStream is being enhanced to receive and parse binary data stream directly. This makes EZStream beneficial to both the ISS International Partners and non-NASA applications (i.e. factory floor monitoring). The options for developing client-side display web pages will be addressed along with the development of tools to allow creation of display web pages by non-programmers.
Ongoing work at National Aeronautics and Space Administration Goddard Space Flight Center (NASA/GSFC), seeks to apply standard Internet applications and protocols to meet the technology challenge of future satellite missions. Internet protocols and technologies are under study as a future means to provide seamless dynamic communication among heterogeneous instruments, spacecraft, ground stations, constellations of spacecraft, and science investigators. The primary objective is to design and demonstrate in the laboratory the automated end-to-end transport of files in a simulated dynamic space environment using off-the-shelf, low-cost, commodity-level standard applications and protocols. The demonstrated functions and capabilities will become increasingly significant in the years to come as both earth and space science missions fly more sensors and the present labor-intensive, mission-specific techniques for processing and routing data become prohibitively. This paper describes how an IP-based communication architecture can support all existing operations concepts and how it will enable some new and complex communication and science concepts. The authors identify specific end-to-end data flows from the instruments to the control centers and scientists, and then describe how each data flow can be supported using standard Internet protocols and applications. The scenarios include normal data downlink and command uplink as well as recovery scenarios for both onboard and ground failures. The scenarios are based on an Earth orbiting spacecraft with downlink data rates from 300 Kbps to 4 Mbps. Included examples are based on designs currently being investigated for potential use by the Global Precipitation Measurement (GPM) mission.
E-Gov is an idea that is very popular these days. Many government agencies are adopting electronic information technology to improve both their internal and external capabilities to communicate with stakeholders and customers. This is an area where the Internet offers huge improvements in responsiveness. Unfortunately, Internet outreach traditionally has not been a budget area that received strong support in most agencies. Today, almost every government agency has some Internet presence: some extensive; others minimal. However, if you really want to reach your stakeholders and customers, just putting information out is not enough to assure it is useful. The most effective outreach sites are those that have moved beyond first generation static designs and concepts to newer communications approaches that stress two-way communication and collection and analysis of customer-oriented performance metrics. This talk discusses a few basic concepts in customer/stakeholder interaction as practiced by the very successful NASA family of websites, Science@NASA. Started 7 years ago as a single website, focusing on the science output of the Space Science Lab at NASA's Marshall Space Flight Center, Science@NASA in 2002 consisted of 6 websites with 450,000 subscribers and garnered over 700 million hits (approx. 64 million visits) in 2002 plus 3 international awards in the past 3 years. Focused content, tying presentation techniques to advanced communications concepts, managing and soliciting subscribers lists, automatic collection of performance metrics, soliciting and responding to customer feedback, and subscriber surveys are among the topics to be discussed. The successful NASAKids Club and the interactivity offered to children will also be covered. The attempt to make the customer/stakeholder DO SOMETHING is critical to our success.
Internet technologies are briefly introduced and those applicable for telemedicine are reviewed. Multicast internet technologies are described. The National Aeronautics and Space Administration (NASA) 'Telemedicine Space-bridge to Russia' project is described and used to derive requirements for internet telemedicine. Telemedicine privacy and Quality of Service (QoS) requirements are described.
Currently there are two approaches to provide Quality of Service (QoS) in the next generation Internet: An early one is the Integrated Services (IntServ) with the goal of allowing end-to-end QoS to be provided to applications; the other one is the Differentiated Services (DiffServ) architecture providing QoS in the backbone. In this context, a DiffServ network may be viewed as a network element in the total end-to-end path. The objective of this paper is to investigate the possibility of providing end-to-end QoS when IntServ runs over DiffServ backbone in the next generation Internet. Our results show that the QoS requirements of IntServ applications can be successfully achieved when IntServ traffic is mapped to the DiffServ domain in next generation Internet.
In this paper, the XNsim approach to achieve Internet-enabled, dynamically scalable collaborative distributed simulation capabilities is presented. With this approach, a complete simulation can be assembled from shared component subsystems written in different formats, that run on different computing platforms, with different sampling rates, in different geographic locations, and over singlelmultiple networks. The subsystems interact securely with each other via the Internet. Furthermore, the simulation topology can be dynamically modified. The distributed simulation uses a combination of hub-and-spoke and peer-topeer network topology. A proof-of-concept demonstrator is also presented. The XNsim demonstrator can be accessed at http://www.jsc.draver.corn/xn that hosts various examples of Internet enabled simulations.
This greenbook captures some of the current, planned and possible future uses of the Internet Protocol (IP) as part of Space Operations. It attempts to describe how the Internet Protocol is used in specific scenarios. Of primary focus is low-earth-orbit space operations, which is referred to here as the design reference mission (DRM). This is because most of the program experience drawn upon derives from this type of mission. Application profiles are provided. This includes parameter settings programs have proposed for sending IP datagrams over CCSDS links, the minimal subsets and features of the IP protocol suite and applications expected for interoperability between projects, and the configuration, operations and maintenance of these IP functions. Of special interest is capturing the lessons learned from the Constellation Program in this area, since that program included a fairly ambitious use of the Internet Protocol.
Networked communications in space are necessary to achieve scalability in terms of the number of communicating nodes but also in terms of the overall system complexity. A key component to such a system is the ability to synchronize clocks, which is the focus of this paper. The so-called Solar System Internet (SSI) will be built upon Delay Tolerant Networking (DTN), which, in analogy to the Internet Protocol (IP), can be considered a suite of protocols necessary for networking in the space domain. Therefore, our goal is to extend this suite to include a DTN clock synchronization capability, analogous to the Network Time Protocol (NTP) used in the Internet. A motivating example of a network in space is NASA’s LunaNet, a vision for a multi-hop multi-path network extending to the moon wherein not all nodes will have direct connections to an authoritative reference clock. In this paper, we propose a general clock synchronization methodology and algorithm that could be used for LunaNet as well as more elaborate time-varying networks. In recent years, DTN has benefited from modeling efforts founded on the mathematical tool of sheaves. Here we continue this work to provide an approach to clock synchronization. Due to the time-varying nature of space networks, absolute consensus is not possible. However, the sheaf Laplacian provides a practical, distributed approach to approximating consensus by allowing data to diffuse through the network. In particular, the sheaf Laplacian is readily computable, lending our approach to implementation. Our approach is well suited to handle the difficulties of space networks. For instance, differences in clock accuracy mean certain nodes are more authoritative than others; we can account for these differences through hierarchies in the network, generalizing the strata in NTP. Furthermore, just as error estimation is an integral part of NTP, we are able to give concrete error bounds for our approach. Indeed, different applications (e.g., communications schedules, pointing, navigation, distributed science) will have different requirements, hence it is necessary to maintain clocks within a given tolerance. We outline some of the necessary steps to turn our approach into a practical network protocol that could be used in DTN, and we conclude the paper with suggestions for future research.
This paper reviews the capability of the Internet as a world-wide NDT communication tool for technical collaboration, dissemination of information and international standards. This paper was written by authors that never personally met (except for two) and despite thousands of miles distance between them the authors managed to work as a team to complete this paper in a very time efficient manner. This success is attributed to the power of the Internet and it represents a simple example of the.
The Mars Polar Lander (MPL) mission is the first planetary mission to use Internet-based distributed ground operations where scientists and engineers collaborate in daily mission operations from multiple geographically distributed locations via the Internet.