Radiation Mitigation in Space: A COTS Approach
September 16, 2015 | BY: Niall HeffernanDownload PDF
When it comes to space vehicle design, whether it is a launcher, a re-entry vehicle or a satellite, the tolerance of on-board electronics to radiation effects becomes one of the most challenging aspects of the design. As the risk of equipment failure due to the radiation effects increases with the altitude and flight duration, the tolerance to radiation effects becomes the crucial criteria for selecting the on board equipment and sub-systems.
In recent times, designers of spacecraft systems have been encouraged by funding Agencies to identify ways and means to mitigate against radiation effects within the scope of limited program budgets while not compromising the overall Mission Safety Assurance requirements. This white paper will discuss how a novel approach to radiation mitigation allows the use of commercial off the shelf (COTS) electronics equipment in a radiation environment, thereby lowering the cost involved in the design, certification, manufacture and deployment of such a system.
Radiation – A Major Problem for Space Equipment Designers
Space radiation consists of highly energetic Protons, Electrons and Heavy Ions. Figure 1 shows the two main sources of space radiation – the Sun and galactic cosmic rays.
Semiconductor components are essential building blocks of modern spacecraft electronics, including data handling equipment.
As radiation interacts with a semiconductor it produces ionization which effectively increases the conductance of the material. As a result, ionizing radiation creates tiny spikes of electrical current in the material. Cumulatively, these current spikes cause degradation of material characteristics and are known as Total Dose Effects. Individually, they can temporary or permanently disturb the function of a device, a phenomena known as Single Event Effects (SEE).
If you were to think about it in terms of the tire on a car, total dose is the equivalent of general wear-and-tear from road use, whereas SEE is the equivalent of a puncture.
Download the white paper to learn more.