ESA collates seven spacecraft data to assess space radiation

Moreover, this new study reveals that these spacecrafts serve as a “good network” to detect solar particle detections in areas where no scientific observations are currently available, or even possible. 

This data could be useful in designing future spacecraft, as well as expanding our understanding of space weather and the threats presented to humans and robotic probes outside Earth's protective barrier.

“Spacecraft are launched with instruments, payloads, and it's thought ‘great – it will do science with that’, but a spacecraft is so much more,” says Beatriz Sanchez-Cano, lead author of the paper and part of the Mars Express science team at the University of Leicester, in an official release.  

“Memory counters reveal a lot, but so do dust impacts on solar panels that tell us about micrometeorites and space debris, huge temperature swings have their effect, too. This kind of experience had by satellites also contributes to science, and it’s all this together that really makes these missions incredible, fantastic,” added Sanchez-Cano. 

The high threat of solar energetic particles 

According to ESA, solar energetic particles (SEPs) are highly charged particles that originate in the solar atmosphere and solar wind and travel at incredible speeds. 

The Sun emits these particles in all directions (the solar wind), but their activity amplifies when the star erupts with massive solar flares and coronal mass ejections.

As a result, huge waves of charged particles can pierce the Earth's magnetic field, posing a serious radiation risk to spacecraft. 

For this reason, the solar energetic particle events are said to be one of the most dangerous weather phenomena in space for future explorers.

The spacecrafts are equipped with gear known as Error Detection and Correction (EDAC) memory counters. They shield a spacecraft computer's memory from any sort of error triggered by the energetic particles hitting on computer circuits. In turn, this could give data on the intense solar outbursts, and its impact on the spacecraft. 

"The extreme environments that missions operate in can put huge stress on the spacecraft hardware. This can mean that even though they have been designed for these scenarios, they don't always behave exactly how we'd like, especially the older the spacecraft gets,” explained Simon Wood, Spacecraft Operations Engineer for Mars Express.   Wood further added: “Engineering data like this has always been vital when flying missions through deep space, but it's exciting to know decades worth of this information can also be used to build a scientific picture of the Solar System. Its why we never throw anything away - you don't know what secrets are being stored in the data beamed down from space."

The results have been published in the journal Space Weather.

Study abstract:

Despite the growing importance of planetary Space Weather forecasting and radiation protection for science and robotic exploration and the need for accurate Space Weather monitoring and predictions, only a limited number of spacecraft have dedicated instrumentation for this purpose. However, every spacecraft (planetary or astronomical) has hundreds of housekeeping sensors distributed across the spacecraft, some of which can be useful to detect radiation hazards produced by solar particle events. In particular, energetic particles that impact detectors and subsystems on a spacecraft can be identified by certain housekeeping sensors, such as the Error Detection and Correction (EDAC) memory counters, and their effects can be assessed. These counters typically have a sudden large increase in a short time in their error counts that generally match the arrival of energetic particles to the spacecraft. We investigate these engineering datasets for scientific purposes and perform a feasibility study of solar energetic particle event detections using EDAC counters from seven European Space Agency Solar System missions: Venus Express, Mars Express, ExoMars-Trace Gas Orbiter, Rosetta, BepiColombo, Solar Orbiter, and Gaia. Six cases studies, in which the same event was observed by different missions at different locations in the inner Solar System are analyzed. The results of this study show how engineering sensors, for example, EDAC counters, can be used to infer information about the solar particle environment at each spacecraft location. Therefore, we demonstrate the potential of the various EDAC to provide a network of solar particle detections at locations where no scientific observations of this kind are available