By Helen Briggs
BBC News science reporter
The Cryosat mission lost in the Arctic Ocean last year minutes after launch from northern Russia will fly again.
The European Space Agency (Esa) has agreed to build a copy of the original £95m (140m-euro) craft.
Early estimates suggest Cryosat-2 could be ready to launch in three years.
The mission will study how the Earth's ice sheets are responding to climate change amid mounting evidence that some areas are thinning.
The UK scientist behind the mission said Cryosat was too important to lose.
In an article on the BBC News website, Professor Duncan Wingham of University College London, said: "Everyone involved should be justifiably proud of their contribution, large or small as it may be, to ensuring that the Cryosat-2 has an opportunity to prove itself.
"For myself, it is a privilege to know that our little mission is so widely supported."
The Esa probe was lost soon after lift-off last October from the Plesetsk Cosmodrome in northern Russia, crashing into the very ocean it was meant to monitor.
Russian investigators later concluded that a problem with the onboard software of the upper stage of the Rockot launch vehicle was to blame.
European ministers agreed in December that re-launching Cryosat was a priority; but the final decision fell to members of Esa's Earth Observation Programme Board who met this week in Paris, France.
Some of the world's leading scientists have expressed their support for Cryosat-2, saying the data will greatly improve our understanding of climate change.
Professor Julian Dowdeswell, director of the Scott Polar Research Institute at Cambridge University, UK, said it would help answer the question of whether the great ice sheets of Greenland and Antarctica are growing or decaying.
Cryosat-2 will fly closer to the poles than previous satellites, providing valuable missing data.
"Previously for the Antarctic we've had a great big 'hole-in-the-doughnut' kind of gap from about 81 degrees south through to the South Pole which is the bulk of the interior of the Antarctic ice sheet," he told the BBC News website.
"Cryosat only leaves a very small hole in the doughnut."
And Volker Liebig, Esa's director of Earth Observation Programmes, added: "This decision is very important, as the scientific community in Europe and elsewhere is eagerly awaiting resumption of the Cryosat mission. We are happy to have obtained approval today."
A preliminary estimate suggests the Cryosat-2 mission can be rebuilt for £73.5m (106m euros). Savings can be made by using existing infrastructure on the ground designed for data processing and satellite operations for Esa's other missions in the Earth Explorer series.
The UK's contribution to the relaunch will come from its Esa Earth observation "subscriptions", which are made through the Natural Environment Research Council (Nerc).