Particle Measurements in Space

Precisely determining the energy and species of charged particles is fundamental to the field of high energy physics. Technical breakthroughs, ingenuity, and improved detector designs have led to remarkable achievements. High energy physics detectors are advanced composite devices with millions of channels of different detector technologies often positioned in strong magnetic fields. While exquisite in design and measurement capabilities, these detection platforms require significant investments in electrical, technical and engineering resources. This design paradigm is not feasible for space applications where size, weight, and power resources are extremely limited. During the infancy of space exploration, many anomalies and even total mission failures of operational satellites were observed. Although it is hard to be certain, it is believed that many of these were the victims of the harsh radiation environment surrounding the Earth. Therefore, an understanding of the natural space radiation environment is not only a scientific endeavor, but a necessity for successful operations of space systems. While the particles in space are like those measured with colliders on Earth, the task of measuring them faces significantly harsher restrictions. Although the access to space has improved in recent times and the cost per kilogram to orbit is lower, about $3000 per kilogram compared to about $60,000 per kilogram during shuttle times, it is still a significant factor to consider when designing detectors. A brief history of particle detection in space, its miniaturization overcoming weight and power restrictions culminating in the usage of pixel detectors will be discussed in the following chapter.