Context:
The European Space Agency has recently embarked on several activities to use the Grid within Astronomy and Earth Observation Communities. The major objectives of these projects have been threefold:
1. Provide access to large amounts of data from different sources
2. Provide a collaborative environment for the development and later maintenance of algorithms to process satellite data
3. Setup a high-performance infrastructure to allow large data simulations
To this extent, the astronomical mission Gaia, which is due to be launched in 2011, was considered a potential candidate, due to the large effort that will be required by the scientific community to process the data. Twenty scientific institutes across Europe will be involved in the next seven years to prepare all the data processing algorithms. The mission will determine the positions of about 1 billion stars in the Milky Way Galaxy down to the micro arcsecond precision and will provide a 3D mapping of the Galaxy, including the radial velocity of some 150,000 stars to provide a dynamic view of the Galaxy.
Large simulations are carried out today to take into consideration all aspects of the instruments on-board, the telemetry stream and the different laws of physics that will effect Gaia observations.
In the field of Earth Observation, the acquisition of data from the Envisat mission and the provision of data products from its various instruments provides an unprecedented challenge for the community. In order to cross-correlate this data with other products from other missions and to offer various applications, from agriculture to environmental alerts requires high performance processing as well as high-speed network links.
Short History
In order to better understand present and future computational requirements, ESA initiated the SpaceGrid study (2001-2003). Its main objectives were to propose a common infrastructure for the multiple disciplines in ESA:
• to assess how GRID technology can serve requirements across a large variety of space disciplines (spacecraft mechanical engineering, space weather, space science, earth observation
• to foster collaboration and enable shared efforts across space applications
• to sketch the design of an ESA-wide (and common) infrastructure
• to demonstrate proof of concept through prototyping
Usage of Grid for Earth Observation purposes was studied by ESA and other parties within the framework of WP9 of the DataGrid project. After project closure ESA has continued its Grid R&D activities to demonstrate the use of Grid for Earth Observation in the project ‘Grid-on-Demand’. Furthermore, dedicate Grid clusters have been installed at ESRIN and ESTEC premises.
Current situation
Within the GAIA project ESA currently uses the GridAssist platform, developed by Dutch Space, as the main vehicle to develop, test and share the Gaia Shell algorithms. A workflow tool, based on the OpenSource Globus protocol, GridAssist coordinates all Gaia’s computational resources and provides uniform access to all the algorithms.
Within THE VOICE project Dutch Space is responsible for the realization of a prototype that will support e-Colloboration within the widely distributed ENVISAT Validation community. Grid technology will be deployed to support computational and collaboration tasks within this community.
The Diligent project, in which ESA participates, aims to integrate Digital Library and Grid technology to create a test-bed system for e-Science, based on the system infrastructure created for the EC's currently running follow-up to DataGrid, called Enabling Grids for E-science in Europe (EGEE).
Future
Grid computing and collaboration is expected to form an important contribution to the European Global Monitoring for the Environment and Security (GMES) program.
In the scientific domain, other future missions having similar requirements to Gaia may adopt a similar approach to GaiaGrid computing.
We foresee a further integration of technologies is needed to support future needs. Computational Grids, Web Services, Virtual Observatories, Semantic Webs, Sensor Webs need to be combined to result into working solutions satisfying the emerging user demands.
Program:
1. Introduction: HPC and Collaboration Needs from Astronomical & Earth Observation Communities [Salim Ansari, ESA-ESTEC]
2. Grid projects – an overview @ESA [Luigi Fusco or Joost van Bemmelen, ESA-ESRIN]
- SpaceGrid
- Grid-on-Demand
- THE VOICE
- Diligent
- Infrastructure
3. GaiaGrid, a mission simulation of the Gaia satellite [Salim Ansari, ESA-ESTEC]
4. GridAssist - Develop Locally, Compute And Collaborate Globally [Dutch Space]
5. Demonstration: Grid processing of GAIA mission simulation [ESA & Dutch Space]
6. e-Collaboration: Grids to Support Instrument Calibration and Validation [Dutch Space]
7. Brainstorm session: Towards Future Needs and Supporting Technologies in Astronomy and Earth Observation
Presentations will be short. Demonstrations are intended to be “life” and interactive. With the brainstorm session we expect to generate ideas and contacts for further research collaborations.
