Europe resumed deployment of its beleaguered Galileo satnav programme on Friday, launching a pair of satellites seven months after a rocket malfunction sent two multi-million euro orbiters awry.

Galileo's seventh and eighth satellites blasted off from Europe's spaceport in Kourou, French Guiana, at 2146 GMT (6:46 pm local time), to join four orbiters already in the constellation.

A Russian Soyuz spacecraft with three crew on board successfully docked at the International Space Station Saturday after blasting off from Kazakhstan, NASA said, launching a year-long mission on the orbiting outpost.

The Soyuz-TMA16M spacecraft's crew included a U.S. astronaut and a Russian cosmonaut who will be the first to spend an entire year on the ISS.

At first sight the Salton Sea looks putrid, with dead fish scattered among patches of fetid water in a vast salty lake in the middle of the Californian desert.

In the fourth year of a historic drought in the western United States, some say the wetland is an environmental time bomb.

The ice floating around Antarctica has thinned by nearly 20 percent, according to research published Thursday, depleting the bulwark that prevents the permanent collapse of glaciers covering the southern continent.

The study, based on satellite measurements between 1994 and 2012 by the European Space Agency, sheds new light on how Antarctic ice responds to climate change.

Japan on Thursday successfully launched a replacement spy satellite, its aerospace agency said, as an existing device comes to the end of its working life.

Tokyo put spy satellites into operation in the 2000s after its erratic neighbour North Korea fired a mid-range ballistic missile over the Japanese mainland and into the western Pacific in 1998.

"That day, we were almost in mourning," said Luc Bagalwa, a geophysics researcher in the eastern Democratic Republic of Congo, recalling the 2002 eruption of the Nyiragongo volcano.

While the ash and deep lava destroyed part of the northeastern city of Goma and prompted the evacuation of hundreds of thousands of people, the recording apparatus in Bagalwa's laboratory had no paper to note the spectacular seismic events.

At first sight the Salton Sea looks putrid, with dead fish scattered among patches of fetid water in a vast salty lake in the middle of the Californian desert. 

In the fourth year of a historic drought in the western United States, some say the wetland is an environmental time bomb.

Hundreds of kilometers below on Earth, their governments are locked in a standoff over Ukraine -- but up in space, Russian cosmonauts and American astronauts are still working together side by side.

The International Space Station (ISS) is one of the rare areas of U.S.-Russian cooperation that has not been hit by the Ukraine crisis and in the latest show of commitment, the next joint mission is set to blast off from Kazakhstan on Friday.

Russia officials say they will resume space tourism in 2018 after years of sending into space only professional cosmonauts and astronauts.

Russia had sent seven paying guests to the International Space Station since 2001 before curtailing the program in 2009. Sending a tourist has been all but impossible since 2011 when the United States shut down its Space Shuttle program and had to rely on Russian Soyuz rockets in order to get into orbit.

NASA's Curiosity rover has found nitrogen on the surface of Mars, a significant discovery that adds to evidence the Red Planet could once have sustained life, the space agency said Tuesday.

By drilling into Martian rocks, Curiosity found evidence of nitrates, compounds containing nitrogen that can be used by living organisms.