James Webb Space Telescope stretches its sunshield

Published on January 10, 2022Written by theregister.com

The James Webb Space Telescope has continued to notch up the milestones on its journey to its destination at the L2 Lagrange Point with the tensioning of its sunshield.

After a successful launch atop an Ariane 5 on 25 December, the observatory has begun unfurling as it hurtles towards its final location. After antennas and sunshield pallets popped out of the spacecraft, the sunshield itself, consisting of five folded membranes, is in the process of being tensioned.
The first layer of the observatory’s kite-shaped sunshield, and the one that is both the largest and closest to the Sun, was tightened to its final, completely taut position on 3 January. The second layer took 74 minutes and the third 71 minutes. By the completion of the third layer, NASA reported that the process (up to that point) had taken five and a half hours.
The fourth layer was successfully tensioned earlier today. The fifth is expected to be completed by the end of the day should things continue to go to plan.
The sunshield is 21.197m x 14.162m (69.5ft x 46.5ft).
“The membrane tensioning phase of sunshield deployment is especially challenging because there are complex interactions between the structures, the tensioning mechanisms, the cables and the membranes,” said James Cooper, NASA’s Webb sunshield manager, based at Goddard Space Flight Center.
“This was the hardest part to test on the ground, so it feels awesome to have everything go so well today.”
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The sunshield is vital because the telescope must be protected from the Sun’s radiation. Tensioning and keeping the layers apart is also essential since if they touch, they conduct heat. “Thus the cold side can’t, well, get very cold,” remarked Mark McCaughrean, senior advisor for Science & Exploration at ESA.
Unlike other infrared observatories, which have required active cooling via cryogenics, the James Webb Space Telescope uses passive cooling to get temperatures down to -233°C for three of its instruments – the Near Infrared Camera (NIRCam), the Near Infrared Spectrograph (NIRSpec), and the Near Infrared Imager and Slitless Spectrograph (NIRISS). NIRISS includes the Fine Guidance Sensor (FGS) used to point the observatory precisely.
A fourth instrument, the Mid-Infrared Instrument (MIRI), uses a dedicated cryo-cooler to bring the temperature down even further, to 7 Kelvin (or just under -266.1°C).
The tensioning of the sunshield, while a critical step, does not mean that scientists and engineers on Earth will able to retreat from the edge of their seats. There remains the deployment of the secondary mirror and the unfolding of the iconic primary mirror among other steps ahead of the L2 insertion burn some 29 days after launch.
And then there is the commissioning of the payload.
“There’s another five & a half months of this to go,” McCaughrean tweeted.
Five and a half months that, just a few short years ago, seemed impossibly distant.
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First analyses of Ryugu asteroid sample published

Published on December 24, 2021Written by theregister.com

Researchers have published the first analyses of samples plucked from asteroid 162173 Ryugu by Japan’s spacecraft Hayabusa2, revealing, for the first time, the physical properties and composition of a carbonaceous asteroid.

The 5.4g of asteroid sample collected from two surface locations on asteroid Ryugu landed in the South Australian outback a year ago before being shipped to Japan for investigation.
Some of the space pebbles went to NASA, but the bulk remained with Japan’s Aerospace Exploration Agency JAXA and its scientists.
Astro-boffins have had high hopes for these samples, as they’ve never before had their hand on a dark and carbon-rich asteroid, or C-type, like Ryugu.
Studies of the samples physical properties revealed the sample resembled the spacecraft’s on-site images of the flying space-rock and the collected material was representative of the asteroid as a whole.
Rich in water and organic matter, the ultra-dark material was a mix of elements rarely seen in meteorites that make it down to Earth, despite these C-type asteroids being the most common in the Solar System. The texture was also unusual, as it was uniformly fine and did not include the round chunky bits of melted minerals known as “chondrules”.
Those characteristic suggest that Ryugu’s parent body was a CI chondrite, a rare meterorite with a composition close to the stuff found in the Sun’s outer shell.
“This demonstrates that Hayabusa2 has returned a sample whose parent body is definitively known and which will give us information about the early stages of the Solar System,” said the authors of one of two papers published on Ryugu Tuesday in the journal Nature Astronomy.
The authors made that assertion as the composition of CI chondrites are similar to the stuff theorized to have made up much of the Solar System when it was just formed.
The results are exciting for supporters of the panspermia theory, which proposes that the building blocks for life are transported across the cosmos via comet or asteroid. C-type asteroids, in particular are thought to have seeded a young Earth with water and other essential life-supporting materials.
Indeed, scientists found organic molecules on the first comet humanity intercepted, Comet 67P/Churyumov-Gerasimenko. There’s no reason known why chunks of comets housing organic materials wouldn’t survive an impact and spread their cargo far and wide.
Of course, beyond the philosophical questions about humanity’s maker, there’s also a very real reason to study asteroids and that is that it would be really great to avoid having one hit the Earth and end all the fun and games here.
Scientists continue to dig in to the Ryugu samples and hope follow up studies might tell us how the Solar System evolved. Comparisons of Ryugu to other asteroids are planned, to test for variations.
In addition to the dust and pebbles, the mission also produced what JAXA referred to as “the world’s first sample return of a material in the gas state from deep space,” so we have more to look forward to than just solid matter.
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New Undersea link to Japan, Europe via Northwest Passage

Published on December 24, 2021Written by theregister.com

In the 15th century, European traders that hoped to reach Asia had problems: a round trip by land or sea took years and involved many lethal perils.

Navigators of the day therefore imagined sailing the “Northwest Passage,” a route across the Atlantic, then over the top of North America, before sliding south to Japan.
Sadly, ice is seldom absent at the far northern latitudes the Passage occupies.
Nor is there a simple route through the glacier-carved archipelago atop Canada.
Navigating the Passage therefore proved impossible for four hundred years, failed attempts like the Franklin Expedition became maritime lore*, and the route turned out to be so finnicky it’s not commercially viable.
In the 21st century, Europeans have a similar problem: network latency between northern Europe and Asia is uncomfortably long.
So Finnish company Cinia and US telco infrastructure company Far North Digital have agreed to build a submarine cable named the Far North Fiber that traverses the Passage.
One end of the cable will be in Japan, and it will touch Alaska and the Canadian Arctic before terminating in Norway, Finland, and Ireland.
The FLAG and SEA-ME-WE3 cables already connect Europe to Asia but pass through the Suez Canal and tricky spots where a determined saboteur would not struggle to find a cable.
Plenty of other routes exist, too, but require cross-connection to other cables or trips on terrestrial networks to cross North America.
Those connections add latency and complexity.
The Far North Fiber will therefore offer both a shorter trip and offer an alternative physical route.
The splendid resource at submarinecablemap.com shows us that while cables are already operating in Arctic climes, some further north than this one would need to pass, they are rare.
This cable will therefore be quite a feat of engineering if the memorandum of understanding signed by Cinia and Far North Digital comes to fruition.
The two companies’ plan calls for the 14,000km cable to carry traffic from 2025.
If that date is achieved, it will beat Russia’s Polar Express cable to market by a year.
Polar Express also uses northern waters to travel from Asia to Europe, over the top of Siberia, but will only land in Russia.
Commercial shipping has used Polar Express’ route for decades, and in recent times sea ice has become scarcer and traffic has increased.
The Register fancies that Cinia and Far North Digital will hope similar conditions make their construction efforts easier.
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Hubble, Hubble, toil and trouble: Space Telescope Woes

Published on July 16, 2021Written by theregister.com

NASA has completed a formal review of what engineers will have to do to switch the Hubble Space Telescope to its backup hardware. This comes more than a month after a problem with a payload computer aboard the veteran observatory sent the telescope into safe mode and engineers scurrying for contingency plans.

Attempts to restart the computer failed, and a switch to a backup of the 1980s-era hardware resulted in the same memory error.
Engineers cast their net wider as time wore on, considering potential issues with a power regulator as a possible culprit as well as the Command Unit/Science Data Formatter (CU/SDF), which sends and formats commands and data.
The hardware is highly redundant, but switching to backups at this level carries its own risks: “To switch to the backup CU/SDF or power regulator, several other hardware boxes on the spacecraft must also be switched due to the way they are connected to the SI C&DH [Science Instrument Command and Data Handling] unit,” NASA posted at the end of June.
It’s not entirely new ground for the team. A similar switch was done in 2008 after a CU/SDF module failed. However, back then a Space Shuttle servicing mission was on the cards for 2009. Today’s engineers have no such luxury.
NASA has therefore spent much of July testing and reviewing procedures on a high-fidelity simulator of the hardware.
Tests were completed last week, and a review aimed at minimising the risks associated with the procedures went ahead earlier this week.
A formal review into all the operations related to the switch to backup hardware has now been completed and there is every chance that engineers will have a go at the procedure later this week – perhaps a bit risky since the investigation into what actually befell the payload computer is not complete.
The Register asked NASA for a look at the reviewed procedures and will update should the agency respond.
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US Military Worried About China’s New ‘Grappling Arm’ Satellite

China has a satellite with an arm – and America worries it could be used to snatch other spacecraft. Send more money to help us protect our space toys, military tells Congress. US military leaders have claimed China has a satellite with a grappling arm, and said its existence highlights the needs for increased funding […]

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