For the last time while it is on Earth, the world's largest and most powerful space science telescope opened its iconic primary mirror. This event marked a key milestone in preparing the observatory for launch later this year.

As part of the NASA's James Webb Space Telescope's final tests, the 6.5-meter (21-foot, 4-inch) mirror was commanded to fully expand and lock itself into place, just like it would in space.

Researchers from the University of Tsukuba have sent mice into space to explore effects of spaceflight and reduced gravity on muscle atrophy, or wasting, at the molecular level.

Gravity is a constant force on Earth, which all living creatures have evolved to rely on and adapt to. Space exploration has brought about many scientific and technological advances, yet manned spaceflights come at a cost to astronauts, including reduced skeletal muscle mass and strength.

Conventional studies investigating the effects of reduced gravity on muscle mass and function have used a ground control group that is not directly comparable to the space experimental group. Researchers from the University of Tsukuba set out to explore the effects of gravity in mice subjected to the same housing conditions, including those experienced during launch and landing. "In humans, spaceflight causes muscle atrophy and can lead to serious medical problems after return to Earth," says senior author Professor Satoru Takahashi. "This study was designed based on the critical need to understand the molecular mechanisms through which muscle atrophy occurs in conditions of microgravity and artificial gravity.

Researchers have confirmed the existence of magnetic plasma waves, known as Alfvén waves, in the Sun's photosphere. The study, published in Nature Astronomy, provides new insights into these fascinating waves that were first discovered by the Nobel Prize winning scientist Hannes Alfvén in 1947.

The vast potential of these waves resides in their ability to transport energy and information over very large distances due to their purely magnetic nature. The direct discovery of these waves in the solar photosphere, the lowest layer of the solar atmosphere, is the first step towards exploiting the properties of these magnetic waves.

The ability for Alfvén waves to carry energy is also of interest for solar and plasma-astrophysics as it could help explain the extreme heating of the solar atmosphere—a mystery that has been unsolved for over a century.

Elusive waves

Alfvén waves form when charged particles (ions) oscillate in response to interactions between magnetic fields and electrical currents.

Within the solar atmosphere bundles of magnetic fields, known as solar magnetic flux tubes, can form.

With rubble from an asteroid tucked inside, a NASA spacecraft fired its engines and began the long journey back to Earth on Monday, leaving the ancient space rock in its rearview mirror.

The trip home for the robotic prospector, Osiris-Rex, will take two years.

Training of the crew for the first entirely private trip to the International Space Station (ISS) is to begin soon, Axiom Space, the company behind the flight, said Monday at a joint press conference with NASA.

Four astronauts are to be launched to the ISS in late January aboard a rocket built by another space company, Elon Musk's SpaceX.

Only one of the four—NASA veteran Michael Lopez-Alegria—has been in space before.

The other three are businessmen—Larry Conner, an American, Mark Pathy, a Canadian, and Eytan Stibbe, an Israeli.

The mission dubbed Ax-1 is to last around 10 days, said Axiom Space president and CEO Michael Suffredini.

The astronauts will work and live in the American section of the space station and plan to conduct a number of scientific experiments while in orbit.

"We'll be starting what I would call serious training next week," said Lopez-Alegria, the Ax-1 commander.

"From there the pace will pick up, and we'll all be immersed essentially full time in ISS systems and Crew Dragon training starting in the fall.