Welcome to the Rad-Sat web site. Rad-Sat is a Highlight Topic Grant funded by the NERC entitled:

Modelling the acceleration, transport and loss of radiation belt electrons to protect satellites from space weather (Rad-Sat).

The project brings together a consortium of scientists from 5 different Groups in the UK, stakeholders from the space industry and a network of international collaborators.

Start date        4 April 2017

End date          30 April 2021

Project now extended to: 30 April 2022

Latest News: Congratulations Professor Richard Horne!

Rad-Sat team leader and head of the British Antarctic Survey Space Weather and Atmosphere Team, Professor Richard Horne was awarded the Gold Medal in Geophysics from the Royal Astronomical Society of 2022, for significant achievement in astronomical and geophysical research. The Gold Medal is the Society’s highest honour, and previous winners include Albert Einstein, Edwin Hubble, Arthur Eddington and Stephen Hawking. The Society awarded Dr Horne the Gold Medal for his exceptional contribution to expanding our understanding of the physics of space weather and dynamic conditions in outer space environments. Achievements of Professor Horne include his discovery that electromagnetic waves in planetary magnetospheres are responsible for accelerating charged particles to relativistic energies and velocities close to the speed of light, underlying BAS’s Radiation Belt Model. Professor Horne has shown innovation, initiative and is recognised as an international leader in the developing space weather science. Well done!


Over the last 10 years the number of operational satellites in orbit has grown from 450 to more than 1400.   We rely on these satellites more than ever before for a wide range of applications such as mobile phones, TV signals, internet, navigation and financial services.  All these satellites must be designed to withstand the harsh radiation environment in space for a design life that can be as long as 15 years or more.

During magnetic storms the electron flux inside the radiation belts can increase by four orders of magnitude on a timescale of a few days, but this increase can be as fast as 2 minutes. The flux can also decrease rapidly over a period of a few minutes, but usually takes place more slowly over a period of several days.   We do not understand why these timescales vary so much.  It is the increase in flux and its duration that poses a major risk to satellites.  Thus to help satellite designers, operators and space insurance assess the impact of space weather and mitigate its effects we need to understand how the radiation belts are formed and what controls the variability.

New results from the NASA Van Allen Probes and THEMIS satellite missions show that wave-particle interactions play the major role in the acceleration, transport and loss of high energy electrons and hence the variability of the radiation belts. Therefore the project focusses on key scientific questions associated with wave-particle interactions.

The Goal

The goal of this proposal is to determine the acceleration, transport and loss of high energy electrons due to wave-particle interactions and use them in state-of–the-art modelling and forecasting of space weather events to protect satellites.

To achieve this goal we have set six scientific objectives.


  1. To investigate the role of magnetosonic waves, hiss, transmitters and lightning generated whistlers on the global dynamics of the radiation belts and develop state-of-the-art modelling and forecasting for space weather events
  2. To determine the properties of magnetosonic waves, hiss, transmitters and lightning generated whistlers and assess their importance for the acceleration and loss of radiation belt electrons
  3. To determine the relative importance of non-linear effects on wave-induced acceleration and loss
  4. To determine the transport of electrons via Ultra-Low Frequency magnetosonic waves, and to determine their role in electron precipitation
  5. To determine how wave-particle interactions depend on the time history of the solar wind driver so as to significantly improve forecasting models
  6. To investigate radiation belt dynamics during shock-driven severe space weather events and provide a new forecasting capability.

The project will deliver new processed data, a better forecasting capability and expertise that will support the UK Government assessment of severe space weather for the National Risk Register and the growth of the satellite industry.