A University of Alberta-led space weather satellite is targeting a launch in 2025 or 2026 after receiving significant funding from the Canada Foundation for Innovation (CFI).
The mission, which is planned to be fully Canadian except for launch services, received $8.1 million from CFI and includes participation from the universities of Calgary and Toronto, as well as private companies Magellan and Honeywell Aerospace.
The $20.3 million mission is not fully funded yet, but principal investigator Ian Mann said he is hopeful other federal and Alberta government agencies will support the mission – and indeed, some are considering financial support right now.
Mann, a physicist at the University of Alberta, noted that this mission follows on from many decades of work Canada has performed studying space, especially in response to solar activity, both on the ground and in space.
“Canada’s been a leader in understanding the dynamic of the space environment in response to solar forces for many decades,” he said. Following installation of ground equipment to track the atmosphere at high latitudes, Canada launched its first satellite – Alouette – in 1961 for studies of the ionosphere, kicking off numerous other space radiation studies by other missions.
The new pan-Canadian mission is called RADiation Impacts on Climate and Atmospheric Loss Satellite (RADICALS). Like its name implies, RADICALS will study the space environment in the high atmosphere to better understand facets such as climate and atmospheric dynamics. The concept has been under study since 2016 and the hope is the new funding will help boost the mission through preliminary design to construction, and to launch and operations.
RADICALS – categorized as a microsatellite at roughly 50 kilos in mass – will launch as a secondary payload on a future rocket mission to an altitude of roughly 600 km, in a polar sun-synchronous orbit. (The launch will be procured internationally as Canada has no orbital launch capabilities in-country.) The prime mission is two years, although investigators hope it could be extended for as long as five years depending on funding, along with the health of the spacecraft and instruments.
The mission will focus on a poorly understood aspect of space weather, which is how much space radiation gets dumped into Earth’s atmosphere after getting trapped in the belts. As Mann pointed out, radiation in the belts can only leave in two directions – out into space, or down into Earth.
Radiation levels in the upper atmosphere can vary considerably depending on what is happening with solar activity, and could have implications for industries such as those who work in airplanes. There also are questions about how this radiation affects ozone in the high atmosphere, above the altitude of the so-called “ozone hole” but still in a region crucial for chemical reactions and energy transport between different regions of the atmosphere.
As the particles precipitate into the middle atmosphere, Mann explained, the particles create nitrogen oxide and hydrogen oxide radicals – known as catalytic destroyers of ozone. Most studies to date have focused on protons (which appear less frequently from the belts, but with great effect), while RADICALS will focus on electrons (which may fall in the atmosphere continuously and have a large alteration on atmospheric processes.)
RADICALS will measure this precipitation as it “tumbles like a cartwheeling gymnast along the direction of orbit,” Mann explained. It will be able to view the full-angle distribution of particles into the atmosphere twice per satellite spin, including how much is precipitating at different latitudes, different times and different solar environments, he said.
“We’ll get a unique picture of what is happening as this radiation hammers its way down into the atmosphere,” he said.
Canadian scientists have participated in numerous missions concerning space radiation, with a recent notable example being the NASA Van Allen Probes, which ran from 2012 to 2019. Another early space mission from the United States, called Explorer 1, discovered bands of radiation surrounding Earth in 1958 called the Van Allen Belts. More recent studies (including from the Probes mission) showed the belts vary in altitude and in structure depending on solar activity.
The altitude of the belts can vary considerably depending on solar activity. The inner region is densest at roughly 3,000 km above Earth – about 7.5 times higher than the International Space Station, but still within the region of many satellite orbits. The outer maximum density tends to be between 15,000 to 20,000 km in altitude, although it can stray quite a bit higher towards geosynchronous orbits.
One immediate worry about radiation and solar activity in the Van Allen belts is what happens with satellites, since they can be damaged through dielectric charging or other processes. Given how much of our world depends on satellites – Earth observation, communications and security, to name a few applications – predicting solar activity and its effects is helpful.
On a longer scale, the measurements from RADICALS will allow scientists to assess the energy input into the atmosphere from space radiation, a unique measurement never before been seen in detail. These effects can be assessed in future climate models and help with our understanding of Earth’s climate as a whole.