NASA Astronomy Picture of the Day

February 23, 2025

Saturn in Infrared from Cassini

Saturn looks slightly different in infrared light. Bands of clouds show great structure, including long stretching storms. Also quite striking in infrared is the unusual hexagonal cloud pattern surrounding Saturn's North Pole. Each side of the dark hexagon spans roughly the width of our Earth. The hexagon's existence was not predicted, and its origin and likely stability remain a topics of research. Saturn's famous rings circle the planet and cast shadows below the equator. The featured image was taken by the robotic Cassini spacecraft in 2014 in several infrared colors. In 2017 September, the Cassini mission was brought to a dramatic conclusion when the spacecraft was directed to dive into the ringed giant.

https://apod.nasa.gov/apod/astropix.html

Chinese scientists turn Boeing’s helium leak crisis into stealth missile tech breakthrough

Updated: 9:57pm, 23 Feb 2025

In an ironic twist of cosmic problem-solving, Chinese researchers have transformed a lingering Nasa headache into a revolutionary propulsion breakthrough that could redefine modern warfare and space travel.

The two Nasa astronauts have been marooned at the International Space Station since June last year after multiple helium leaks incapacitated the thruster systems of their spacecraft – Boeing’s troubled Starliner capsule.

As a result, helium, the ultralight gas used to pressurise liquid rocket fuel, has become an emblem of engineering frailty.

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Now, Chinese scientists report they have harnessed that very flaw to achieve what Pentagon planners have long sought: a solid-fuel rocket capable of tripling its thrust on demand while chilling its exhaust to near-ambient temperatures, rendering it almost invisible to infrared sensors.

In a study published in Acta Aeronautica et Astronautica Sinica this month, the team led by aerospace researcher Yang Zenan, from Harbin Engineering University, detailed how injecting helium into traditional solid rocket motors via micron-scale pores triggers a thrust surge.

Helium does not burn, but optimal ratios of helium to combustion gas (1:4) boosted the specific impulse by 5.77 per cent, enabling thrust levels to soar 300 per cent through adjustable injection, Yang and his colleagues wrote.

paywall

https://www.scmp.com/news/china/science/article/3299454/chinese-scientists-turn-boeings-helium-leak-crisis-stealth-missile-tech-breakthrough