R. A. DALEY ET AL. Scientifi c Resource Access System: A Concept for Getting “Living With a Star” Information to Do Science Rose A. Daley, Elisabeth A. Immer, Brand I. Fortner, and Michele B. Weiss Answering complex science questions often means that a scientist must fi nd and use a variety of scientifi c resources, including static and dynamically generated data in different formats, complex data assimilation models, and conversion and analysis tools. Although the Internet has led to an explosion of accessible scientifi c resources, it has also created a Babel of incompatible formats, data descriptions, and access methods from many disparate sources. An evolving prototype called the Scientifi c Resource Access System (SRAS) is being developed that uses metadata and commonly understood scientifi c concepts to provide easier discovery and access to these necessarily heterogeneous resources for “doing science.” This concept simplifi es the integration of distributed scientifi c resources within a single system and enables the interconnection of complex data systems. An additional goal of SRAS is to eliminate the need for specialized integration software and the need to force data standardization on participating resources. Both are infeasible in Internet- based scientifi c data environments, where the additional effort and expense required for such solutions would effectively eliminate a substantial quantity of important scientifi c resources. Instead, the SRAS uses existing protocols and formats along with robust meta- data to simplify integration. INTRODUCTION The Scientifi c Resource Access System (SRAS) is large amount of valuable legacy data, and an indetermi- being developed to support a NASA initiative called nate variety of future data and data formats, all of which Living With a Star (LWS),1 but it encompasses the entire must be combined to support broad, interdisciplinary solar-terrestrial scientifi c discipline. LWS is a space sci- approaches to scientifi c analysis. ence exploration program covering the domain from the The fundamental goal of the SRAS is to give the Sun all the way to the Earth (Fig. 1) for over a decade space science community a simple and complete method of missions, observations, and experiments. Therefore, to gather and share static and dynamically generated LWS includes a wide variety of scientifi c disciplines (e.g., data, metadata, documentation, and model results, as solar, space, ionospheric, and magnetospheric physics), a well as associated analysis tools and services, without 22 JOHNS HOPKINS APL TECHNICAL DIGEST, VOLUME 26, NUMBER 1 (2005) SCIENTIFIC RESOURCE ACCESS SYSTEM The heart of the SRAS is a con- ceptual model of commonly under- stood scientifi c concepts, augment- ed by robust metadata supplied by the creator of the resource to facili- tate resource discovery and access. SOHO The SRAS does not presume to per- TIMED form all of the operations needed by solar-terrestrial scientists. Instead, it focuses on leveraging the capa- ACE bilities developed within the space SuperDARN science and other research com- munities, and it provides unique capabilities • To discover available resources for a “concept of interest” • To discover relationships among resources • To access heterogeneous re- sources from a variety of sources • To simplify integration with Figure 1. The solar-terrestrial science domain. Living With a Star science encom- other systems to augment passes myriad scientifi c disciplines, scientifi c resources, and data formats. The ACE, SOHO, TIMED, and SuperDARN spacecraft illustrate the diversity of resource types capabilities needed by the solar-terrestrial scientist. requiring all of these resources to be centrally located or THE CHALLENGES OF SOLAR- administered. It acts as an intermediary between the user TERRESTRIAL SCIENCE and the distributed data repositories, enabling access to Consider the following scenario involving the chal- known resources regardless of their format, geographic lenges faced by the solar-terrestrial scientist: location, status (active vs. historical), or origin (mea- sured vs. modeled). Furthermore, the SRAS simplifi es The winds and composition of the Earth’s ion- the integration of resources by enabling the intercon- osphere are affected by geomagnetic storms and nection of complex data systems without the need to energetic particle events,2 which are both pro- create specialized software for each system or resource. Finally, because of the long life cycle of the LWS initia- duced by solar variability. Over time, which aspect tive, the SRAS also anticipates frequent opportunities of the solar variability dominates the ionospheric for technology transition as new technologies emerge properties? and their viability is demonstrated, both to improve its A scientist could use any number of resources capabilities and to replace obsolete technology. Specifi c to investigate this issue. The Advanced Compo- considerations for easing this transition, both into the sition Explorer (ACE) spacecraft measures solar SRAS as new technologies mature and out of the SRAS wind properties that drive geomagnetic storms; as technologies are demonstrated to be effective, have the Global Geospace Science Program (Wind) been incorporated into the system’s design. spacecraft is a backup when data from ACE are As the set of resources needed to perform the LWS not available. Solar energetic particle measure- program and solar-terrestrial science evolves and ments also come from ACE, while measures of becomes increasingly complex, automated support fl uxes in the magnetosphere come from the Fast will also become increasingly common. To effectively Auroral SnapshoT (FAST), Solar Anomalous and interact in this environment, the SRAS prototype Magnetospheric Particle Explorer (SAMPEX), includes an innovative Web-based user interface specifi - Geostationary Operational Environmental Sat- cally designed for scientists familiar with the available ellite (GOES), Polar Orbiting Environmental resources as well as interdisciplinary scientists who may Satellites (POES), and Defense Meteorologi- be less comfortable with those same resources. It also cal Satellite Program (DMSP) spacecraft. Data includes a system interface specifi cally designed so that on the evolution of geomagnetic storms can be other software systems can use the services provided by derived from the Imager for Magnetosphere-to- the SRAS. Aurora (IMAGE) spacecraft’s Far Ultraviolet JOHNS HOPKINS APL TECHNICAL DIGEST, VOLUME 26, NUMBER 1 (2005) 23 R. A. DALEY ET AL. Imager (FUV) instrument, and the IMAGE/High for its particular scientifi c discipline or to address spe- Energy Neutral Atom (HENA) imager measures cifi c mission constraints, and none of these standards remote sensing of the aurora and plasmasphere, and formats have been widely adopted or supported by with the POLAR spacecraft’s Ultraviolet Imager low-cost commercial software. (UVI) serving as backup. The scientist can also Because of this heterogeneous environment (notion- get data on ionospheric properties from the Global ally depicted in Fig. 2), undue effort is diverted from sci- Ultraviolet Imager (GUVI), TIMED Doppler entifi c investigations to understanding and overcoming Interferometer (TIDI), and Sounding of the each particular resource’s specifi c acquisition circum- Atmosphere using Broadband Emission Radiom- stances. Cross-mission studies and investigations by sci- etry (SABER) instruments on the Thermosphere, entists outside of the missions are often precluded simply Ionosphere, Mesosphere Energetics and Dynamics because the effort to acquire data is so intimidating. To (TIMED) spacecraft. effectively perform solar-terrestrial integrated science, more capable systems that can provide unifi ed access A signifi cant challenge for the scientist is data selec- to multiple, physically distributed resources, available tion, which depends on the locations of the spacecraft in different formats and at various levels of support, in their orbits to ensure that they are measuring the are needed. The SRAS is being designed and proto- same places at the same times. If lists of storms and typed specifi cally to provide a means for solving these particle events exist, they can help to identify the problems and making the solution available to a broad places (time intervals) to start looking. Otherwise, community of space scientists. data for the entire time interval must be searched to develop a list. Once an event time is known, does the scientist have to pick up all the data to decide if SRAS OVERVIEW the observing situation is good? Or is there a way to Concept understand what the next limiting factor is? The sci- entist must also choose an equal number of quiet times The SRAS concept is driven by four primary con- to ensure that the changes measured in the iono- straints: a long-term life cycle, integration of heteroge- sphere are not just part of the natural variation. With neous resources, involvement of a diversity of scientists, several hundred events occuring per solar cycle, this and fi nite science budgets. task requires a lot of effort just to get to the data of 1. Long-term life cycle for both development and deploy- interest. ment. Because LWS satellites will not be launched for To address these problems in the current data envi- several years, many challenges will not be fully experi- ronment, the scientist would need to fi nd each appro- enced for quite some time. Given the rapidly changing priate Web site, visit each indi- vidual instrument’s or mission’s Web site,