Two satellites featuring laser technology developed by Australian National University scientists in Canberra have blasted into space as part of a joint NASA and German mission to measure the Earth's gravity and climate change.
The Gravity Recovery and Climate Experiment Follow-on (GRACE-FO) was launched from California's Vandenberg Air Force Base onboard a SpaceX Falcon 9 rocket early on Wednesday morning.
Its purpose is to track gravitational changes by recording shifts in the world's oceans, ice shelves and other waterways.
"This can tell us about changes in sea level and it can give us a complete map of the melting of ice in Greenland or Antarctica, but it can also tell us how the groundwater changes in the Murray Darling Basin from one month to the next," ANU quantum science professor Daniel Shaddock, who led the Australian research team, told AAP.
The two satellites will travel about 200km apart at a 500km altitude, circling the earth once every 90 minutes and building up monthly maps of Earth's gravity.
Laser beams will fire between each of the spacecraft to help gather as precise measurements as possible.
When the first satellite passes over a region with a higher mass concentration, such as a mountain or valley, the gravitational pull strengthens and causes it to accelerate.
Its distance from the second satellite then changes by about one thousandth of a millimetre, Prof Shaddock said, and the laser beam between the two spacecraft measures this small change.
These measurements can reveal information about the mass below such as changes in the quantity of water, providing clear evidence of the impacts of climate change.
"Where irrigation is becoming overused or where drought is causing issues, there may not be enough water left in the aquifers that people have come to rely on," Prof Shaddock said.
Prototypes of the laser technology installed on the satellites was developed by ANU scientists using a $4.7 million Australian Space Research Grant.
"This is the same technology that we're developing for the multi-billion-dollar gravitational wave detector mission we'll launch in around a decade," Prof Shaddock said.
NASA has spent $US430 million ($A567 million) on the new project and the GFZ German Research Centre for Geosciences has invested 77 million euros ($A120 million).
GRACE-FO continues the legacy of NASA and German space agency DLR's initial GRACE mission, launched in March 2002 for a five-year observation of water, ocean and glacier changes but which lasted until October 2017.
