ESA's Optical Ground Station is located at the Teide Observatory, Tenerife

Under the Space Situational Awareness (SSA) programme, Europe is acquiring the capability to independently watch for objects and natural phenomena that could harm satellites in orbit or infrastructure – such as power grids – on the ground.

The SSA Preparatory Programme is being implemented as an ESA Optional Programme with financial participation by 13 Member States. 

During the 2009-12 preparatory phase, SSA-PP is primarily concerned with:

• Governance and data policy definition
• Designing the overall architecture of the future European SSA system
• Federation of existing European assets
• Development of precursor services
• Radar 'breadboard' (test-bench model of future surveillance radar)
• Development of pilot data centres

Some of these activities are taking place in cooperation with partners such as national space agencies, European scientific and research institutes, defence ministries and regional, national and EU/EC-level governments.

Programme focus

To achieve this, ESA's SSA programme is focusing on three main areas:

• SST - Space surveillance and tracking of objects in Earth orbit
  Watching for active and inactive satellites, discarded launch stages and fragmentation debris that orbit the Earth.
• SWE - Space weather
  Monitoring conditions at the Sun and in the solar wind, and in Earth's magnetosphere, ionosphere and thermosphere, that can affect space-borne and ground-based infrastructure or endanger human life or health.
• NEO - Near-Earth objects
  Detecting natural objects that can potentially impact Earth and cause damage.

Each of these is being implemented as a 'segment', analogous to the dedicated 'ground segment' - computers and other resources on the ground - that traditionally support each ESA satellite in space.

2009-11 activities

During the 2009-12 Preparatory Phase, the SSA team is active in four areas:

1. SSA Core Element: Comprising activities related to system architecture, governance, data policy, security and the SST segment
2. Space Weather Element: Including development of both the SWE Segment and the NEO Segment
3. Radar Element: Focusing on the specifications and design for a future radar system and creation of a prototype radar
4. Pilot Data Element: All activities related to common data storage and system-wide management for all segments

Note that not all ESA Member States contributing to SSA are participating in all areas.

During the initial stages, one of the team's critical tasks is to communicate with industry, potential partners, European national governments, scientific and research institutions and future customers to define customer requirements and launch precursor services.

Federated European assets

The team is also identifying and assessing existing European assets that may be federated, with national agreement, into the overall SSA system.

Radar image of Envisat acquired by the TIRA radar at Germany's Fraunhofer Gesellschaft

This will help eliminate duplication at the European level and ensure that current centres of scientific and technical expertise can contribute to SSA products and services.

These federated assets, which may include optical and radar surveillance capabilities, data processing and analytical expertise or scientific research centres will later be complimented by newly built infrastructure, including search radars and optical survey telescopes. Dedicated satellite missions may also be launched as part of SSA.