NASA has launched two identical satellites into space from California's Vandenberg Air Force Base with the aim of better managing Earth's water resources.
The GRACE-FO mission's satellites - which will orbit the Earth at a height of some 220 kilometres for at least six months - were sent aloft on board a Falcon-9 rocket on Tuesday afternoon after the initial launch last Saturday had to be scrapped.
The satellites will measure the monthly changes in the oceans' water content and the size of the ice caps to determine how climate change is affecting the planet.
NASA is scheduled to publicly release the first data collected by the satellites in 180 days, but the information provided by them will be analysed by scientists every 30 days.
Changes over the course of a month are minimal and so the "interesting" thing to study will be the aggregate numbers over longer periods, the mission's chief scientist, Frank Webb, said at a press conference prior to launch.
The two Gravity Recovery and Climate Experiment Follow-On (GRACE-FO) satellites will allow scientists to produce monthly maps of water distribution and climate shifts, among other things.
Tuesday's launch is the second phase of the GRACE mission, which was originally sent into space in 2002 and marked 15 years of space exploration last year.
During that time, GRACE measured the loss of ice in Antarctica, identified patterns in changing ocean levels, discovered anomalies in the storage of underground water and monitored the California drought from 2011-2017.
The data collected were "very important" for the scientific community, resulting in more than 30,000 publications and constituting the first steps toward improving global water management.
The mission is a collaborative project between NASA and the German Research Centre for Geosciences (GFZ).
