Archive for September, 2021

Sep 10 2021

New Spacesuits

Published by under Technology

One of the technologies that had to be developed in order to return to the Moon, and possibly go on to Mars, is spacesuits. It may seem like we already have developed adequate spacesuit technology, since we used them on the Moon during the Apollo missions, but this is not true. The Apollo suits were only designed to survive for days on the Moon, not for the much longer missions the Artemis program plans. They were also very clumsy, as you can tell from watching any Apollo footage of the astronauts.

Developing the next generation of spacesuits has proven more challenging than initially thought. Recently NASA announced delays in completing their Artemis spacesuits, which will be available no sooner than 2025, at a development cost of over $1 billion. If we managed to develop spacesuits usable on the Moon in the 1960s, why is this proving so challenging six decades later? Essentially it’s because our goals are more ambitious, but let’s review the challenges.

The Moon is a harsh environment, most obviously because it is a near vacuum. At a minimum spacesuits need to maintain sufficient pressure to keep astronauts alive and comfortable. Current suits use a pressure of 4.3 psi (pounds per sq inch). One atmosphere of pressure is 14.7 psi, which means the suits are pressurized to the equivalent of 30,000 feet altitude. You can compensate for the lower pressure by increasing the percentage of oxygen in the air mix. Why use such low pressure? Because this pressure causes the suit to be tight. At one full atmosphere of pressure the suit would be so tight the astronauts couldn’t move.

Another option is to use a skin-tight suit, with direct pressure on the skin. This would be a much skinnier suit and allow for greater movement, but such suits would be very expensive to build, and would have to be minutely customized to each individual wearer. They would also be challenging to get in and out of. This might require some new fabric technology that can “shrink wrap” around the wearer after being put on. But there are no plans to develop this technology, so for now we are stuck with pressurized suits.

Continue Reading »

No responses yet

Sep 09 2021

Electric Vehicles by the Numbers

Published by under Technology

I recently purchased a full electric vehicle (EV) and so far I’m very satisfied with the purchase. The functionality and performance is just superior, in my opinion, to similar internal combustion engine (ICE) vehicles. The up front cost is a little higher than for a similar ICE vehicle, but that difference is coming down, especially if you consider the reduced cost of operation from reduced fuel and maintenance costs. In fact, depending on the specifics some EVs may be cheaper over the lifetime of the car vs a similar ICE vehicle. According to Consumer Reports, for example:

The Tesla Model 3 is priced lower than the gas-powered BMW 330i, and priced only about $2,000 more than an Audi A4. But the savings on operating costs for the Model 3 are about $17,000 when compared with either of the popular German gas-powered sedans.

This will only get better as battery technology improves and EV mass production increases. But the primary reason many people may purchase an EV is because they believe it is better for the environment, and they are correct. However, there is often a lot of confusion over how to properly compare EV to ICE vehicles. Let’s look just at carbon footprint – EVs do require more energy to produce, largely because of their battery, so they begin with a larger carbon footprint than a comparable ICE vehicle. Exactly how much more depends, again, on lots of variables, but mostly the size of the battery. For a 300 mile range EV the upfront carbon footprint is about twice that of an ICE.

Continue Reading »

No responses yet

Sep 07 2021

The Aging ISS

Published by under Technology

The International Space Station (ISS) is getting old. Construction started on the station in 1998 and it has been continuously occupied since November 2000. Construction took 10 years, 30 missions, 15 space agencies, and 15 countries to complete. The lifespan of the modules that make up the ISS was originally set at 15 years, but this has been extended to 30 years, with the ISS commissioned through 2028. It is unclear if it will be extended beyond that.

Throughout this time the station has been repaired and upgraded, but the basic infrastructure remains. There is a certain amount of unavoidable aging that happens to hull, maintaining pressure in the challenging conditions of low Earth orbit. Without environmental control, temperature variation on the ISS would range from 250 degrees F on the sun-facing side and -250 F on the sun-opposite side. Temperature variation like this tends to fatigue material. It is therefore unclear what will happen to the ISS, and to orbiting space stations, after 2028.

The ISS cost $150 billion to build, and $3.5 billion per year to maintain. The ROI has largely been research in microgravity, including researching the ability to maintain extended stays in space. NASA plans to deorbit the ISS after 2028, and has no plans for a replacement. Its vision is to largely cede low Earth orbit to private companies. There are at least two companies with plans for their own stations, Axiom and Bigelow Aerospace. Both companies are planning modules that will attach to the ISS, and then detach and become their own free-floating stations once the ISS is decommissioned.

One of the ISS partners, Russia, has commitments to 2025. It is increasingly looking like they plan on pulling out at that time, and some speculate this is because they wish to focus on their own station. They are starting to warn about the age and condition of the ISS, especially their own modules. In July the Nauka research module’s thrusters fired accidentally, temporarily throwing the ISS out of its usual orientation. There have also been several air leaks in the Russian Zvezda service module where some of the crew sleeps. Russia is now warning that 80% of the components on their modules are past the expiration date, and that small cracks are appearing and may spread catastrophically.

Continue Reading »

No responses yet

Sep 03 2021

Trust in Science May Lead to Pseudoscience

Published by under Skepticism

The ultimate goal of scientific skepticism is to skillfully use a process that has the maximal probability of accepting claims that are actually true and rejecting those that are false, while suspending judgment when an answer is not available. This is an open-ended process and is never complete, although some conclusions are so solid that questioning them further requires an extremely high bar of evidence. There are many components to scientific skepticism, broadly contained within scientific literacy, critical thinking skills, and media savvy. Traditional science communication focuses on scientific literacy (the so-called knowledge deficit model), but in the last few decades there has been copious research showing that this approach is not only not sufficient when dealing with many false beliefs, it may even be counterproductive.

A new study offer more evidence to support this view, highlighting the need to combine scientific literacy with critical thinking in order to combat misinformation and false claims. The study focuses on the effect of trust in science as an independent variable, and combined with the ability to critically evaluate scientific evidence. In a series of four experiments they looked at acceptance of false claims regarding either a fictional virus, or false claims about GMOs and tumors:

Depending on experimental condition, however, the claims contained references to either (a) scientific concepts and scientists who claimed to have conducted research on the virus or GMOs (scientific content), or (b) lay descriptions of the same issues from activist sources (no scientific content).

They wanted to see the effect of citing scientists and research on the acceptance of the false claims. As predicted, referring to science or scientists increased acceptance. They found that subjects who scored higher in terms of trust in science were more likely to believe false claims when scientists were cited – so trust in science made them more vulnerable to pseudoscience. For those with low trust in science, the presence or absence of scientific content had no effect on their belief in the false claims. These results replicated in the first three studies, using the fictional virus and the GMO claims.

Continue Reading »

No responses yet

Sep 02 2021

Bionic Arms

The term “bionics” was coined by Jack E. Steele in August 1958. It is a portmanteau of biologic and electronic. Martin Caidin used the word in his 1972 novel, Cyborg (which is another portmanteau of cybernetic organism). But the term really became popularized in the 1970s TV show, The Six Million Dollar Man. Of course, at the time bionic limbs seemed futuristic, perhaps something we would see in a few decades. Thirty years always feels like far enough in the future that any imagined technology should be ready by then. But here we are, almost 50 years later, and we are nowhere near the technology Steve Austin was sporting. Bionics, as depicted, was more like 100 or more years premature. This is tech more appropriate to Luke Skywalker’s hand in Star Wars, rather than some secret government project in the 1970s.

We are, however, making progress, which I have been writing about periodically here. Now a team at Cleveland Clinic has produced a robot arm tested in two subjects, and they are breaking out the term “bionic” to describe their technology. They achieve their level of functionality by combining three aspects of a brain-machine interface connecting to a robotic limb – intuitive motor control, touch sensation, and kinesthetic sensation (simulating proprioception with vibration). The kinesthetic sensation allows the user to feel the robotic limb’s movements. The authors write:

Here, we show that the neurorobotic fusion of touch, grip kinesthesia, and intuitive motor control promotes levels of behavioral performance that are stratified toward able-bodied function and away from standard-of-care prosthetic users.

Continue Reading »

No responses yet

« Prev