Australian-made space weather satellite CUAVA-1 was placed into orbit from the International Space Station on Wednesday night. Launched to the space station in August on a SpaceX rocket, a major focus of this shoebox-sized CubeSat is to study what radiation from the Sun does to Earth’s atmosphere and electronic equipment.
Space weather such as solar flares and changes in the solar wind affect Earth’s ionosphere (a layer of charged particles in the upper atmosphere). This in turn affects long-range radio communications and the orbits of some satellites, as well as creating fluctuations in the electromagnetic field that can wreak havoc with electronics in space and on the ground below.
The new satellite is the first satellite designed and built by the Australian Research Council Training Center for CubeSats, UAVs and their Applications (or CUAVA for short). It houses payloads and technology demonstrators built by collaborators from the University of Sydney, Macquarie University and UNSW-Sydney.
One purpose of CUAVA-1 is to help improve space weather forecasts, which are currently very limited. Alongside its scientific mission, CUAVA-1 represents a step towards the Australian Space Agency’s goal of expanding the local space industry to 20,000 jobs by 2030.
satellite and space weather
While the Australian Space Agency was only created in 2018, Australia has a long history in satellite research. In 2002, for example, FedSat was one of the first satellites in the world to carry a GPS receiver onboard.
Space-based GPS receivers today make it possible to regularly measure the atmosphere around the world for weather monitoring and prediction. The Bureau of Meteorology and other weather forecasting agencies rely on space-based GPS data in their forecasts.
Read more: Lost in space: Australia reduced from space leader to escape even in 50 years
Space-based GPS receivers also make it possible to monitor the Earth’s ionosphere. From an altitude of about 80 km to 1,000 km, this layer of the atmosphere transitions from a gas of uncharged atoms and molecules to a gas of charged particles, both electrons and ions. (A gas of charged particles is also called a plasma.)
The ionosphere is the site of beautiful auroral displays that are common at high latitudes during moderate geomagnetic storms, or “bad space weather”, but there is more to it.
The ionosphere can cause difficulties for satellite positioning and navigation, but it is also sometimes useful, such as scanning the horizon or transmitting ground-based radar and radio signals it can be turned off. .
Why space weather is so hard to predict
Understanding the ionosphere is an important part of operational space weather forecasting. We know that the ionosphere becomes highly irregular during severe geomagnetic storms. It disrupts the radio signals that pass through it, and causes surges of electric current in power grids and pipelines.
During severe geomagnetic storms, large amounts of energy are thrown into Earth’s upper atmosphere near the north and south poles, while also altering currents and flows in the equatorial ionosphere.
This energy is dissipated through the system, causing widespread changes throughout the upper atmosphere and changing high-altitude wind patterns over the equator hours later.
In contrast, X-rays and UV radiation from solar flares directly heat the atmosphere (above the ozone layer) above the equator and mid-latitudes. These changes affect the amount of drag experienced in low-Earth orbit, making it difficult to predict the paths of satellites and space debris.
Even outside geomagnetic storms, there are “quiet-time” disturbances that affect GPS and other electronic systems.
Read more: Daily space weather forecasts will help keep your GPS on target
Currently, we cannot accurately predict bad space weather about three days ahead. And the effects on the flow of bad space weather on Earth’s upper atmosphere, including GPS and communications disturbances and changes in satellite drag, are even more difficult to forecast ahead of time.
As a result, most space weather forecasting agencies are limited to “nowcasting”: observing the current state of space weather and projecting it for the next few hours.
Much science will be needed to understand the connection between the Sun and Earth, how energy from the Sun moves through the Earth system, and how these systems affect the technology we rely on for everyday life. Huh.
This means more research and more satellites, especially for the equatorial to mid-latitudes that are relevant to Australians (and indeed most people on Earth). We hope that CUAVA-1 is a step toward a grouping of Australian space weather satellites that will play an important role in future space weather forecasting.