ISS Artificial Gravity Study Shows Promise For Long Duration Spaceflight

June 8, 2021 by 105 Comments

The International Space Station is humanity’s most expensive gym membership.

Since the earliest days of human spaceflight, it’s been understood that longer trips away from Earth’s gravity can have a detrimental effect on an astronaut’s body. Floating weightless invariably leads to significantly reduced muscle mass in the same way that a patient’s muscles can atrophy if they spend too much time laying in bed. With no gravity to constantly fight against, an astronauts legs, back, and neck muscles will weaken from disuse in as little as a week. While this may not pose an immediate problem during spaceflight, astronauts landing back on Earth in this physically diminished state are at a higher risk of injury.

Luckily this problem can be largely mitigated with rigorous exercise, and any orbiting vessel spacious enough to hold human occupants for weeks or months will by necessity have enough internal volume to outfit it with basic exercise equipment such as a treadmill or a resistance machine. In practice, every space station since the Soviet Union’s Salyut 1 in 1971 has featured some way for its occupants to workout while in orbit. It’s no replacement for being on Earth, as astronauts still return home weaker than when they left, but it’s proven to be the most practical approach to combating the debilitating aspects of long duration spaceflight.

Early NASA concept for creating artificial gravity.

Of course, there’s an obvious problem with this: every hour spent exercising in space is an hour that could be better spent doing research or performing maintenance on the spacecraft. Given the incredible cost of not just putting a human into orbit, but keeping them there long-term, time is very literally money. Which brings us back to my original point: astronauts spending two or more hours each day on the International Space Station’s various pieces of exercise equipment just to stave off muscle loss make it the world’s most expensive gym membership.

The ideal solution, it’s been argued, is to design future spacecraft with the ability to impart some degree of artificial gravity on its passengers through centripetal force. The technique is simple enough: just rotate the craft along its axis and the crew will “stick” to the inside of the hull. Unfortunately, simulating Earth-like gravity in this way would require the vessel to either be far larger than anything humanity has ever launched into space, or rotate at a dangerously high speed. That’s a lot of risk to take on for what’s ultimately just a theory.

But a recent paper from the University of Tsukuba in Japan may represent the first real steps towards the development of practical artificial gravity systems aboard crewed spacecraft. While their study focused on mice rather than humans, the results should go a long way to codifying what until now was largely the stuff of science fiction.

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Mariner 4: Our First Up-Close Look At Mars

June 3, 2021 by 51 Comments

In the grand scheme of things, it wasn’t all that long ago that the entire body of knowledge of our solar system was built solely with Earth-based observations. Turning first their naked eyes to the heavens, and then a succession of increasingly complex and sensitive optical and radio telescopes gathering light from all across the spectrum, our astronomically curious forbears did a commendable job working out the broad strokes of what’s going on in the neighborhood.

But there’s only so much information that can be gathered by instruments operating at the bottom of a roiling ocean of air, so when the opportunity to send instruments to our planetary neighbors began to be possible some 60 years ago, scientists started planning how to accomplish it. What resulted was the Mariner program, a series of interplanetary probes launched between 1962 and 1973 that performed flyby missions of the inner planets.

The list of accomplishments of the Mariner program is long indeed, and the number of firsts achieved by its ten spacecraft is impressive. But it is Mariner 4, the first flyby mission of Mars, which set the stage for a lot of the science being done on and around Mars today, and the first mission where NASA wisely took a “pics or it didn’t happen” approach to planetary science. It was the first time a TV camera had traveled to another world, and it was anything but a sure bet that it would pay dividends.

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Increased Neutron Levels At Chernobyl-4: How Dangerous Is Corium?

May 14, 2021 by 60 Comments

When the Chernobyl nuclear plant suffered the power output surge that would destroy its #4 reactor, a substance called ‘corium‘ was formed. This originally lava-like substance formed out of the destroyed fuel rods along with surrounding materials, like concrete, that made up the reactor. The corium ultimately cooled down and left large amounts of solid corium in the rooms where it had pooled.

Over the past few days there have been numerous reports in the media regarding a ‘sudden surge’ in neutron flux levels from this corium, with some predicting a ‘second Chernobyl disaster’. Obviously, this has quite a few people alarmed, but how dire are these neutron output changes exactly, and what do they tell us about the condition of the corium inside the ruins of the #4 reactor building? Continue reading “Increased Neutron Levels At Chernobyl-4: How Dangerous Is Corium?” →

The Soviet RBMK Reactor: 35 Years After The Chernobyl Disaster

May 5, 2021 by 66 Comments

Thirty-five years ago, radiation alarms went off at the Forsmark nuclear power plant in Sweden. After an investigation, it was determined that the radiation did not come from inside the plant, but from somewhere else. Based on the prevailing winds at that time, it was ultimately determined that the radiation came from inside Soviet territory. After some political wrangling, the Soviet government ultimately admitted that the Chernobyl nuclear plant was the source, due to an accident that had taken place there.

Following the disaster, the causes have been investigated in depth so that we now have a fairly good idea of what went wrong. Perhaps the most important lesson taught by the Chernobyl nuclear plant disaster is that it wasn’t about one nuclear reactor design, one control room crew, or one totalitarian regime, but rather the chain of events which enabled the disaster of this scale.

To illustrate this, the remaining RBMK-style reactors — including three at the Chernobyl plant — have operated without noticeable issues since 1986, with nine of these reactors still active today. During the international investigation of the Chernobyl plant disaster, the INSAG reports repeatedly referred to the lack of a ‘safety culture’.

Looking at the circumstances which led to the development and subsequent unsafe usage of the Chernobyl #4 reactor can teach us a lot about disaster prevention. It’s a story of the essential role that a safety culture plays in industries where the cost of accidents is measured in human life.

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The Fascinating World Of Fasciation

April 22, 2021 by 45 Comments

The other day, I saw this gigantic mutant strawberry on reddit that looked like it had either been growing in a radiation zone, hitting the gym regularly, or sprinkled with magic dust. I immediately felt more than mildly interested in this phenomenon, which is called fasciation.

As it turns out, fasciation is fairly rare occurrence that nonetheless occurs in a wide variety of vascular plants. These mutant strawberries may be a bit unnerving to look at, but they are totally safe to eat. The only problem is that you’re more likely to come across a fasciated dandelion or daisy out in the wild than a strawberry or pineapple at the grocery store because the so-called ugly produce tends to be weeded out.

Fasciation is essentially unregulated tissue growth that occurs when the apical meristem, better known as the growing tip of the plant strays from shooting upward in cylindrical fashion and instead splays out flat, resulting in ribbon-like plant stems, elongated or multiple flower heads, and semi-circular strawberries.

Regular and fasciated mule’s ears from Wikipedia

Although fasciation tends to present as a flattened main stem, the phenomenon can occur nearly anywhere in the plant — the root, stem, leaves, flower heads, or fruit. It can be localized to just one area, or it affect the entire plant.

Fasciation gets compared to cancer because it has a number of causes and ways of expression, but it’s not quite as harmful or scary. Some races of plants exhibit extreme expression of fasciation. While it’s not fatal, it’s also not ideal, because the condition can result in broken tissues, distorted organization, and a decrease in fertility.

Fasciation: How does it work?

One absolute unit of dandelion. Image via Wild Yorkshire

Fasciation has many causes both internal and external. Internally, it happens because of a hormonal imbalance in the growth cells, a bacterial or viral infection, or a random genetic mutation. There are also environmental causes, like chemical exposure, cold and frost exposure, or fungi, mite, and insect attacks.

The wonder of fasciation knows no geographical, climatic, ecological, or taxonomical bounds among vascular plants. It equally affects annuals, biennials, and perennials; woody and herbaceous plants; shrubs, trees, and vines. Although fasciation can occur in any vascular plant, it is quite common in the rose (includes strawberries), legume, sunflower, and cactus families, and is often found among dandelions and snapdragons.

Some vascular plants are prone to fasciation and prized for it, like the cockscomb (Celosia cristata) flower. A few fasciated flora have even become objects of reverence, like the Virgin Mary appearing on a slice of toast. There was once a fasciated pumpkin vine growing in South India. The twenty-foot-long fasciated portion drew huge crowds of people to worship it, believing the vine to be an incarnation of King Cobra or Naga Sarpa, messenger of the god Vishnu.

This spring, I’ll be looking high and low for abnormal dandelions and daisies. I’ve already started scouting the produce at the grocery store for giant strawberries and found these two in the same box. Won’t you join me? We’re probably more likely to find fasciated fruits or flowers than four-leaf clovers.

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Hackaday Links: April 4, 2021

April 4, 2021 by 17 Comments

Can I just say that doing a links roundup article in a week that includes April Fool’s Day isn’t a fun job? Because it’s not. I mean, how can you take something like reports of X-rays flowing from Uranus seriously when they release the report on such a day? It sure looks like a legitimate story, though, and a pretty interesting one. Planets emitting X-rays isn’t really a new thing; we’ve known that Jupiter and Saturn are both powerful X-ray sources for decades. Even though Uranus is the odd child of our solar system, finding evidence for X-ray emissions buried in data captured by the Chandra observatory in 2007 was unexpected. Astronomers think the X-rays might be coming from Uranus’ rings, or they might be reflections of X-rays streaming out from the sun. Or, it might be the weird alignment of the gas giant’s magnetic field causing powerful aurorae that glow in the X-ray part of the spectrum. Whatever it is, it’s weird and beautiful, which all things considered isn’t a bad way for things to be.

Another potential jest-based story popped up this week about the seemingly impossible “EmDrive”. It seems that when you appear to be breaking the laws of physics, you’re probably doing it wrong, and careful lab tests showed that fuel-free propulsion isn’t here yet. One would think it was self-obvious that filling a closed asymmetrical chamber with microwaves would produce absolutely no thrust, but EmDrive proponents have reported small but measurable amounts of thrust from the improbable engine for years. A team at TU Dresden found otherwise, though. Even though they were able to measure a displacement of the engine, it appears to be from the test stand heating up and warping as the RF energy flowed into the drive chamber. By changing the way the engine was supported, they were able to cancel out the dimensional changes that were making it look like the EmDrive was actually working.

Want to use surface-mount parts, but don’t want to bother spinning up an SMD board? Not a problem, at least if you follow the lead of David Buchanan and perform no-surface surface-mount prototyping. We stumbled upon this on Twitter and thought it looked cool — it’s got a little bit of a circuit sculpture feeling, and we like the old-school look of plain 0.1″ perfboard. David reports that the flying leads are just enameled magnet wire; having done our share of scraping and cleaning magnet wire prior to soldering, we figured that part of the build must have been painful. We pinged David and asked if he had any shortcuts for prepping magnet wire, but alas, he says he just used a hot blob of solder and a little patience while the enamel cooked off. We still really like the style of this build, and we applaud the effort.

Speaking of stumbling across things, that’s one of the great joys of this job — falling down algorithmically generated rabbit holes as we troll about for the freshest hacks. One such serendipitous was this YouTube channel documenting a really nice jet engine build. We’ve seen plenty of jet engines before, but very few with afterburners like this one has. There’s also something deeply satisfying about the variable-throat nozzle that Praendy built for the engine — it’s a level of complexity that you don’t often see in hobbyist jet engines, and yet the mechanism is very simple and understandable.

The other rabbit hole we discovered was after reporting on this cool TIG tungsten grinding tool. That took us into The Metalist’s back catalog, where we found a lot of interesting stuff. But the real treat was this automatic tube polisher (video), which we have to say kept us guessing up to the very end. If you’ve got 12 minutes and you enjoy metalworking builds at all, watch it and see if you’re not surprised by the cleverness of this tool.

And finally, we had heard of the travails of Anatoli Bugorski before, but never in the detail presented in this disturbing video. (Embedded below.)

Who is Anatoli Bugorski, you ask? He is a Russian particle physicist who, while working in an accelerator lab in 1978, managed to get his head directly in the path of a 76 GeV proton beam. Despite getting a huge dose of radiation, Bugorski not only survived the accident but managed to finish his Ph.D. and went on to a long career in nuclear physics. He also got married and had a son. He was certainly injured — facial paralysis and partial deafness, mainly — but did not suffer anything like the gruesome fates of the Chernobyl firefighters or others receiving massive radiation doses. The video goes into some detail about how the accident happened — two light bulbs are better than one, it turns out. We enjoyed the video, but couldn’t stop thinking that Bugorski was the Russian atomic-age equivalent of Phineas Gage.

Move Over Cesium Clock, Optical Clocks Are Taking Over

March 26, 2021 by 26 Comments

We normally think of atomic clocks as the gold standard in timekeeping. The very definition of a second — in modern times, at least — is 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of a stationary cesium-133 atom at a temperature of 0K. But there is a move to replace that definition using optical clocks that are 100 times more accurate than a standard atomic clock.

In recent news, the Boulder Atomic Clock Optical Network — otherwise known as BACON — compared times from three optical clocks and found that the times differed a little more than they had predicted, but the clocks were still amazingly accurate relative to each other. Some of the links used optical fibers, a method used before. But there were also links carried by lasers aimed from one facility to another. The lasers, however didn’t work during a snowstorm, but when they did work the results were comparable to the optical fiber method.

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