This weekend sees the 45th anniversary of the launch of Cos-B, the first satellite to be launched under the banner of the newly created European Space Agency, on 9 August 1975.

Cos-B was the first European mission to study gamma-ray sources and to be dedicated to a single experiment. The concept for Cos-B was first put forward by the European scientific community in the mid-1960s and approved by the European Space Research Organisation (ESRO) Scientific and Technical Committee in 1969.

"Its mission was to map the sky, in particular the Milky Way, in the light of gamma rays with energy greater than 50 MeV. Such gamma rays may be produced by cosmic rays (relativistic protons and electrons), interacting with the interstellar medium, starlight and magnetic fields," said Brian Taylor, the former ESA Cos-B Project Scientist.

Despite a nominal lifetime of two years, ESA's Cluster is now entering its third decade in space. This unique four-spacecraft mission has been revealing the secrets of Earth's magnetic environment since 2000 and, with 20 years of observations under its belt, is still enabling new discoveries as it explores our planet's relationship with the Sun.

As the only planet known to host life, Earth occupies a truly unique place in the Solar System. The Cluster mission, launched in the summer of 2000, was designed and built to study perhaps the one main thing that makes Earth a unique habitable world where life can thrive. This one life-enabling thing is Earth's powerful magnetosphere, which protects the planet from the bombardment by cosmic particles but also interacts with them, creating spectacular phenomena, such as polar lights.

Helium is the second most abundant element in the universe after hydrogen. But scientists aren't sure just how much there actually is in the Sun's atmosphere, where it is hard to measure. Knowing the amount of helium in the solar atmosphere is important to understanding the origin and acceleration of the solar wind—the constant stream of charged particles from the Sun.

In 2009, NASA launched a sounding rocket investigation to measure helium in the extended solar atmosphere—the first time we've gathered a full global map. The results, recently published in Nature Astronomy, are helping us better understand our space environment.

The head of Russia's space agency said Friday that Roscosmos wants to return to Venus and bring back soil samples and build spacecraft that will surpass Elon Musk's rockets.

Last week America's first crewed spaceship to fly to the International Space Station in nearly a decade returned safely to Earth, splashing down in the Gulf of Mexico.

The mission was carried out jointly by NASA and Musk's SpaceX. Its Falcon 9 rocket is semi-reusable.

"We are making a methane rocket to replace the Soyuz-2," Roscosmos chief Dmitry Rogozin said in an interview with state news agency RIA Novosti.

He said it will be a reusable space complex, noting that it will be possible to use its first stage at least 100 times.

"Of course we are looking at what our American colleagues are doing," said Rogozin. "But our engineers are trying to take a shortcut—not to repeat what our SpaceX colleagues are doing but surpass them.

Researchers from Kobe University and the National Institute of Technology, Oshima College have conducted a detailed reanalysis of image data from Voyager 1, 2 and Galileo spacecraft in order to investigate the orientation and distribution of the ancient tectonic troughs found on Jupiter's moon Ganymede. They discovered that these troughs are concentrically distributed across almost the entire surface of the satellite. This global distribution indicates that these troughs may be actually part of one giant crater covering Ganymede.

Based on the results of a computer simulation conducted using the "PC Cluster" at the National Astronomical Observatory of Japan (NAOJ), it is speculated that this giant crater could have resulted from the impact of an asteroid with a radius of 150km. If so, the structure is the largest impact structure identified in the solar system so far.

The European Space Agency's JUICE (Jupiter Icy Moon Explorer) mission, which will be launched in 2022 and arrive in Jupiter's system in 2029, aims to increase our knowledge regarding Jupiter's satellites, including Ganymede.