The upper-stage helium tank of the Ariane 3 that was launched in 1985 was recovered in Uganda in 2002 after re-entry. Molten aluminum splashes were discovered on the tank, which have been identified as deposits from local fixings.

The ESA and CNES (French Government Space Agency) want to further investigate how the splashes were caused and the potential effects on titanium and stainless steel materials by recreating, for the first time, this extreme environment and re-entry scenario on the lab scale.

Dr. Yunus Azakli, Engineering Lead for Materials Discovery and Prototyping, adapted the Arcast SC100 at the Royce Discovery Center, Sheffield, to drop molten aluminum on to sheets of Ti-6Al-4V and 316L that had been heated by a specially designed mini furnace to recreate the Ariane 3 materials found in 2002 following its re-entry.

The conditions during atmospheric Earth re-entry of spacecraft can cause some aluminum alloy parts to melt and deposit onto other metallic components. The interaction of such ejecta with titanium components such as helium pressure tanks has, so far, not been widely researched and there is uncertainty on the surface reactions during re-entry.

On 8 January 2024, NASA launched Peregrine Mission One, which carried capsules to the moon containing human remains and DNA samples. The goal was to deposit human remains on the lunar surface, and to release the content of the capsules in space.

Some of the only firm opposition to the mission came from the Native American Navajo Nation. According to their culture, such activity is a desecration of the moon. NASA's response was telling: they were unable to check the payloads' contents, as they belonged to a private company.

Private companies depositing human remains in space is not a new idea: in 1999, an orbiter was deliberately crashed near the lunar south pole, scattering the ashes of the astronomer Eugene Shoemaker. Though it was a NASA craft, the capsule carrying Shoemaker's ashes had been arranged by a private company.

As more and more private actors venture into space, new issues are emerging. International law needs to promptly and carefully regulate all space activity in order to safeguard the future of space exploration.

Anthropogenic contamination: the human footprint in space

If you need to fly in the afternoon of April 8, you might want to grab a pair of solar eclipse glasses.

Airlines and government officials say it is safe to travel during the April 8 once-in-a-lifetime event. The Federal Aviation Administration is forecasting 47,137 flights to operate on April 8.

Health officials are warning eclipse viewers to wear protective eyewear, and that doesn't rule out travelers. The sun's intense brightness can damage eyes in seconds. It'll be damaged even quicker at more than 30,000 feet in the air, said Eric Christian, a senior research scientist at NASA's Goddard Space Flight Center and an eclipse expert.

"The sun will be a little bit brighter, but you shouldn't ever look at it except during totality without either approved eclipse glasses or in the correct pinhole camera," Christian said. "Even the smallest little piece of the sun sticking out can actually damage your retina. Be very careful."

Experts say travelers flying along the path of totality, from Mexico into the northeastern United States and Canada, may experience a longer eclipse from the clouds based on how much closer they are to the sun.