The ESA has reported it is using data originally gathered for what it terms spacecraft “housekeeping” gathered aboard the Rosetta and Mars Express missions to learn more about cosmic rays. Cosmic rays are bursts of high-energy radiation, and the data gathered by the spacecraft helps scientists understand how cosmic rays behave at Mars and in the inner solar system. The housekeeping data gathered by the spacecraft and its components is typically used by engineering teams to monitor the health of the spacecraft and diagnose faults.
The data includes information for component health and on/off status, among other information. The data can be linked to scientifically interesting phenomena and is viewed as a valuable scientific resource that is typically unexplored. For example, spacecraft operating in space are commonly hit by charged particles from the Milky Way galaxy, including cosmic rays. Cosmic rays are particularly challenging because they can cause damage to electronic components if they hit space hardware and can threaten humans in orbit around Earth and on missions deeper into space.
Here on Earth, the atmosphere surrounding the planet protects the surface from cosmic rays. Space missions log when cosmic rays hit an onboard computer and cause memory errors, known as error detection and correction. Since it launched, Mars Express has been collecting those measurements, and recently teams accessed the data collected since 2005, providing a data set spanning 15 years.
Multiple factors influence the intensity of a cosmic ray within our solar system, one of those factors is where the sun is in its 11-year activity cycle and the distance from the sun. With the data Mars Express and Rosetta recorded, scientists can explore the sun-cosmic Ray relationship in detail. The scientists say this is the first time Error Detection And Correction data has been used to study events occurring in the longer term.
However, the data has been used to explore short-term solar events in the past. After sifting through the data, scientists found that cosmic rays behave very similarly with respect to the sun at Mars as they do at Earth and are strongly influenced by the solar cycle. The team also determined that cosmic ray counts increase by around five percent per astronomical unit.