Science Frontiers: From Space Milestones to Climate Challenges

Recent science news highlights include Boeing Starliner's successful docking at the ISS, concerns over uranium fuel for U.S. reactors, discoveries about planet-forming disks around small stars, China's moon sample return mission, Malaysia's turtle conservation challenges, China's space cooperation with the U.S., and SpaceX's Starship landing success.

Following is a summary of current science news briefs.

Boeing Starliner's first astronaut crew welcomed aboard space station

Boeing's new Starliner capsule and an inaugural two-member NASA crew safely docked with the International Space Station on Thursday, meeting a key test in proving the vessel's flight-worthiness and sharpening Boeing's competition with Elon Musk's SpaceX. The rendezvous was achieved despite an earlier loss of several guidance-control jet thrusters, some of them due to a helium propulsion leak, which NASA and Boeing said should not compromise the mission.

Uranium fuel planned for high-tech US reactors a weapons risk, scientists say

A special uranium fuel planned for next-generation U.S. nuclear reactors poses security risks because it could be used without further enrichment as fissile material in nuclear weapons, scientists said in an article published on Thursday. The fuel, called high-assay low-enriched uranium, or HALEU, is enriched to levels of up to 20%, compared with about 5% for the fuel that powers most existing reactors. Until recently it was made in commercial amounts only in Russia, but the United States wants to produce it to fuel a new wave of reactors.

Planet-forming disk around small star offers big surprises

Stars about the size of our sun are not the most common ones in the Milky Way. Much smaller stars are way more common - and those host the most rocky planets in the galaxy, the type in focus as scientists search for worlds capable of harboring life.

New research is providing insight into how planets form around these small stars, called very low mass stars (VLMS), showing how the chemistry in the planet-forming disks of gas and dust surrounding them differs substantially from such disks observed around stars like the sun.

China's Chang'e-6 transfers moon samples to spacecraft, set for return to Earth

China's Chang'e-6 probe transferred samples it collected from the moon's far side to a spacecraft in lunar orbit on Thursday, state news agency Xinhua reported. After receiving the samples, the uncrewed spacecraft will fly back to Earth, with an expected landing in China's Inner Mongolia region on June 25. If successful, China will be the first country to ever return lunar matter from the side of the moon that permanently faces away from Earth.

In Malaysia, warmer temperatures mean fewer male turtles, hurting conservation efforts

On a secluded Malaysian beach, a group of volunteers carefully retrieved newly laid sea turtle eggs in the sand and moved them to a shady, cooler location, in response to fears by researchers that warmer weather is leading to fewer male hatchlings. The temperature of the developing turtle eggs is what determines sex. Observers at the Chagar Hutang Turtle Sanctuary on Redang Island believe they are already seeing fewer males being hatched due to climate change - with the situation made worse this year by prolonged hot and dry spells caused by the El Niño weather phenomenon.

China says open to space cooperation with US but 'hurdles' remain

China remains open towards cooperation with countries including the United States in space, the foreign ministry said on Thursday, following congratulations from U.S. space agency NASA on China's Chang'e-6 mission to the far side of the moon. But the United States needs to remove obstacles towards further cooperation, Mao Ning, a spokesperson at the ministry, said at a regular news conference.

Genome study shows how horses galloped into human history

The advent of horse-based transportation represented one of the seminal moments for humankind, connecting ancient peoples by enabling them to move quickly over long distances for the first time while also transforming how wars were waged. But the timing of equine domestication and the subsequent broad use of horse power has been a matter of contention. An analysis of genome data from 475 ancient horses and 77 modern ones is providing clarity. It revealed that domestication actually occurred twice - the first time being a dead end - and traced the rise of horse-based mobility to around 2200 BC in Eurasia, centuries later than previously thought.

SpaceX's Starship survives return to Earth, aces landing test on fourth try

SpaceX's Starship rocket survived a fiery, hypersonic return from space and achieved a breakthrough landing demonstration in the Indian Ocean on Thursday, completing a full test mission around the globe on the rocket's fourth try. Starship's controlled fall into the Indian Ocean just 65 minutes after launching from Texas capped the latest advance in the company's test-to-failure rocket development campaign, a multibillion-dollar effort by Elon Musk's space company to build a reusable satellite launcher and moon lander.