Satellite Radiation Risk Forecasts (Sat-Risk)

Lead Research Organisation: University of Reading
Department Name: Meteorology


Our society relies on satellites more than ever before, from the use of mobile phones to broadcasting and Earth observation. The use of GPS navigation, positioning and timing signals has grown considerably and we now use these signals in ways that were never foreseen, for example in agriculture and stock market trading. The modern world has also become more connected and built up dependencies that are no longer clearly identifiable. It is therefore essential that we take every reasonable precaution to ensure that satellites are protected.

Space Weather poses one of the most important threats to satellites in orbit, primarily through radiation exposure. Radiation exposure can increase within a few minutes, by a ten thousand fold or more, and remain high for days, even months. For example, in 2003 during a large space weather event known as the Halloween storm radiation levels were highly disturbed and approximately 10% of the entire satellite fleet were affected by satellite anomalies (malfunctions) leading to service interruption and in one case the complete loss of a scientific satellite costing $640 million (Cannon et al., 2013).

In 2012 the UK Government recognised the importance of space weather as a low frequency high impact event and included it on the National Risk Register (Cabinet Office, 2012). This was revised in 2017 with a recommendation for more investment into forecasting as a means of mitigating the impact. More recent research suggests that with current forecasting capability the loss of gross domestic product to the UK would be around £2.9 billion but with more investment in enhanced forecasting this could be reduced to £0.9 billion (Oughton et al., 2019). The purpose of this proposal is to provide enhanced forecasting to help reduce the impact on satellites. Currently there are over 2,200 operational satellites in orbit (December 2019).

This proposal brings together scientists from across the UK with stakeholders from the UK Met Office. The goal is to develop a real-time system to forecast radiation exposure to satellites for a range of different orbits, and quantify the risk of damage or degradation. We will do this by taking research models of the Earth's radiation belts - regions of high energy electrons and protons trapped by the external geomagnetic field and which circulate around the Earth - and turn them into operational forecasting models. The models will use real-time data from ground and space to forecast radiation exposure up to 24 hours ahead for different orbits, including geostationary orbit, Low Earth orbit and medium Earth orbit. It will also include data on radiation storms and cosmic rays. The particle radiation levels will then be used to calculate the damaging radiation effects on electronic components and solar arrays and compared to design guidelines to assess the risk of damage.

The project will also include four research elements which are specifically targeted at reducing the uncertainty in the forecasts.

The project will deliver a world leading forecasting capability for the Met Office that will help satellite operators take mitigating action, help satellite designers develop more resilient design and space insurance reduce the risk of loss. It will also support the growth of the satellite industry and the UK National Risk Register.

1. Cannon, P, S., et al. (2013), Extreme Space Weather: Impacts on Engineered Systems and Infrastructure, Royal Academy of Engineering, London, SW1A 2WH.
2. Cabinet Office, (2012), National risk register of civil emergencies, Whitehall, London SW1A 2WH,
3. Oughton et al., (2019), A Risk Assessment Framework for the Socioeconomic Impacts of Electricity Transmission Infrastructure Failure Due to Space Weather: An Application to the United Kingdom, Risk Analysis,

Planned Impact

We have identified the following non-academic users who will benefit from our research:

UK Met Office

The research proposed in this project (Sat-Risk) is to develop an operational space weather forecasting system for the UK Met Office that is specially tailored to help protect satellites in orbit. The UK Met Office will be the direct beneficiaries. The system will be able to provide forecasts of particle radiation exposure to satellites up to 24 hours ahead for low and medium Earth and geostationary orbit. At the end of the project the system will be licensed to the UK Met Office for continued operation.

Satellite operators

Satellite operators have an interest in the safe and reliable operation of their spacecraft. Space weather events can cause satellite anomalies (malfunctions) resulting in loss of service and in some cases total satellite loss. It can also mean a delay in reaching orbit and lost revenue if an anomaly affects electric orbit raising. Our research will lead to a step-change in space weather forecasting which will provide satellite operators with space weather situation awareness. This will enable them to plan mitigating action, for example, to suspend orbit manoeuvres and software updates, to ensure more staff are available to deal with problems, to have back-up systems immediately available, and when appropriate to inform users that some services may be at risk.

Space insurance

Satellite insurance via Lloyds of London is a major international business. Insurance will benefit from the system as the forecasts should enable operators take mitigating action if a space weather event is imminent and hence reduce the risk of damage or an insurance claim. If there is an anomaly, space insurance may also benefit from an independent record of forecasts which could be interrogated to help understand the cause of an anomaly.

Satellite construction companies - Airbus, Boeing, Lockheed Martin

Satellite designers must protect satellites from the harsh radiation environment in space. They use models of the radiation environment to design for the 'reasonable worst case' but there is a very large uncertainty. There are thousands of new satellites planned for launch into regions of space where we have very little information on the radiation environment or its variability. Furthermore, the growing use of electric instead of chemical propulsion means that satellites spend much more time in the Earth's intense radiation belts where there is a higher risk of degradation. Our forecasts and research will provide more information on the radiation environment that satellite designers will be able to use to help assess the amount of shielding needed to protect satellites.

General public

It is widely acknowledged that space research attracts young people into Science, Technology, Engineering and Mathematics (STEM subjects).The press coverage of the UK Astronaut Tim Peak and the International Space Station, is compelling evidence of the public's interest in space research. Dissemination of the forecasting system will help attract young people into the STEM subjects.

Government and Policy makers

Extreme space weather was put on the UK National Risk Register in 2012 and revised in 2017 with a recommendation for more investment into forecasting as a means of mitigating the impact. Recent research suggests that with current forecasting capability the loss of gross domestic product to the UK would be around £2.9 billion but with more investment in enhanced forecasting this could be reduced to £0.9 billion (Oughton et al., 2019). The research proposed in this project (Sat-Risk) will help protect our national critical infrastructure and help deliver for the Government a more prosperous space industry. The PI (Richard Horne) is a member of the Space Environment Impacts Expert Group (SEIEG) and will be able to provide advice to Government through this Group at meetings with the Cabinet Office.
Title Pitch-angle diffusion experiments to investigate temporal variability of diffusion coefficients 
Description ASCII files documenting the results from a series of numerical experiments using one-dimensional Fokker-Planck equation to study pitch-angle diffusion in Earth's radiation belt for temporally-varying pitch-angle diffusion coefficients. Results from these files were used to obtain Figures 3 and 4 in "The implications of temporal variability in wave-particle interactions in Earth's Radiation Belts", Watt et al., [GRL, 2020] There are two ensemble experiments with temporal variability scale equal to 2 minutes, and 6 hours. The 2 minute ensemble files have naming convention: XX_2minvariation_L3.1d where XX indicates the run number in the ensemble. There are 60 experiments in the ensemble. The 6 hour ensemble files have naming convention: runXX_6hvariation_L3.1d where 1 
Type Of Material Database/Collection of data 
Year Produced 2020 
Provided To Others? Yes  
Impact This model is the first to use stochastic parameterization in a space weather context.