Science

1244 Articles

Two Stage Refrigerator Is Chill

May 16, 2023 by 13 Comments

Every time we check in with [Hyperspace Pirate] he’s trying to make things cold. Really cold. His recent two-part video shows a propane vapor compression system that can go down to -37° C as well as a two-stage system using homemade ethylene that can get to -83° C. He’s trying to get to -100°, so he’s close, and we have no doubt he’ll get there.

The video explains that using two different refrigerants makes the design more practical. At the low temperatures involved, you have to deal with compressor oil freezing. There is a lot of theory required to design an efficient cooler and a lot of know-how required to make gas-tight connections with all the different materials involved.

Using propane in both stages did provide a little additional cooling. But using ethylene in the second stage didn’t work as expected. There were two issues to work through. Part of it was the average temperature of the system, and also, the homemade ethylene needed purification. The ethylene purification setup was almost as complex as the main system and also reminded us, for some reason, of the movie Darkstar. It didn’t work as well as he wanted, which means we have to wait for part two to see it all actually working.

We’ve seen this same guy make dry ice. He’s also tried to make liquid nitrogen, too.

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Astronaut Tracy Caldwell in the International Space Station. (Credit: NASA)

Making The Case For All-Female Exploration Missions To Mars And Beyond

May 16, 2023 by 118 Comments

A recent study in Nature Scientific Reports by Jonathan P. R. Scott and colleagues makes the case for sending exclusively all-female crews on long-duration missions. The reasoning here is simple: women have significant less body mass, with in the US the 50th percentile for women being 59.2 kg and 81.8 kg for men. This directly translates into a low total energy expenditure (TEE), along with a lower need for everything from food to water to oxygen. On a long-duration mission, this could conceivably save a lot of resources, thus increasing the likelihood of success.

With this in mind, it does raise the question of why female astronauts aren’t more commonly seen throughout Western space history, with Sally Ride being the first US astronaut to fly in 1983. This happened decades after the first female Soviet cosmonaut, when Valentina Tereshkova made history in 1963 on Vostok 6, followed by Svetlana Savitskaya in 1982 and again in 1984, when she became the first woman to perform a spacewalk.

With women becoming an increasingly more common sight in space, it does bear looking at what blocked Western women for so long, despite efforts to change this. It all starts with the unofficial parallel female astronaut selection program of the 1950s.

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Artemis II Laser Communications

Artemis II Will Phone Home From The Moon Using Laser Beams

May 14, 2023 by 52 Comments

[NASA] Astronauts will be testing the Orion Artemis II Optical Communications System (O2O) to transmit live, 4K ultra-high-definition video back to Earth from the Moon. The system will also support communication of images, voice, control channels, and enhanced science data.

Aboard Orion, the space terminal includes an optical module, a modem, and a control system.  The optical module features a four inch telescope on a dual gimbal mount. The modem modulates digital information onto laser beams for transmission back to Earth, and demodulates data from laser beams recieved from Earth. The control system interfaces with avionic systems aboard Orin to control and point the communications telescope.

On Earth, facilities including the Jet Propulsion Laboratory and the White Sands Complex will maintain high-bandwidth optical communication links with Orion. Information received from Orion will be relayed to mission operations, scientists, and researchers.

NASA’s Laser Communications Relay Demonstration (LCRD) showcases the benefits of optical communications.  Traditionally, missions relied upon radio communication, but improved technology will better serve space missions that generate and collect ever-increasing quantities of data. Optical communication solutions can provide 10 to 100 times the bandwidth of radio frequency systems. Other improvements may include increased link distances, higher efficiency, reduced interference, improved security, and reductions in size and weight. Our Brief History of Optical Communication outlines many of these advantages.

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Remembering Virginia Norwood, Mother Of NASA’s Landsat Success

May 13, 2023 by 13 Comments

Virginia T. Norwood passed away earlier this year at the age of 96, and NASA’s farewell to this influential pioneer is a worth a read. Virginia was a brilliant physicist and engineer, and among her other accomplishments, we have her to thank for the ongoing success of the Landsat program, which continues to this day.

The goal of the program was to image land from space for the purpose of resource management. Landsat 1 launched with a Multispectral Scanner System (MSS) that Norwood designed to fulfill this task. Multispectral imaging was being done from aircraft at the time, but capturing this data from space — not to mention deciding which wavelengths to capture — and getting it back down to Earth required solving a whole lot of new and difficult problems.

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What Is A Schumann Resonance And Why Am I Being Offered A 7.83Hz Oscillator?

May 12, 2023 by 112 Comments

Something that probably unites many Hackaday readers is an idle pursuit of browsing AliExpress for new pieces of tech. Perhaps it’s something akin to social media doomscrolling without the induced anger, and it’s certainly entertaining to see some of the weird and wonderful products that can be had for a few dollars and a couple of weeks wait. Every now and then something pops up that deserves a second look, and it’s one of those that has caught my attention today. Why am I being offered planar PCB coils with some electronics, described as “Schumann resonators”? What on earth is Schumann resonance, anyway? Continue reading “What Is A Schumann Resonance And Why Am I Being Offered A 7.83Hz Oscillator?” →

The Bicycle (and More) Explained

May 8, 2023 by 25 Comments

They say a picture is worth a thousand words, but an animation, then, must be worth a million. Make that animation interactive, and… well, we don’t know how many words it is worth, but it is plenty! That’s the idea behind [Bartosz Ciechanowski’s] blog where he uses clever interactive animations to explain the surprisingly complex physics of riding a bicycle.

The first animation lets you view a rider from any angle and control the rider’s pose. Later ones show you how forces act on the rider and bicycle, starting with example wooden boxes and working back up to the original bike rider with force vectors visible. As you move the rider or the bike, the arrows show you the direction and magnitude of force.

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Metallurgist working by the blast furnaces in Třinec Iron and Steel Works. (Credit: Třinecké železárny)

We Already Live In A Hydrogen Economy: Steel Production, Generator Cooling, And Welding Gas

May 4, 2023 by 61 Comments

Although generally hydrogen is only mentioned within the context of transportation and energy storage, by far the most useful applications are found in industrial applications, including for the chemical industry, the manufacturing of steel, as well as that of methanol and fertilizer. This is illustrated by how today most of all hydrogen produced today is used for these industrial applications, as well as for applications such as cooling turbo generators, with demand for hydrogen in these applications rapidly increasing.

Currently virtually all hydrogen produced today comes from natural gas, via steam methane reformation (SMR), with potentially methane pyrolysis making natural gas-derived hydrogen a low-carbon source. The remainder of hydrogen comes from coal gasification and a small fraction from electrolysis of water. The hydrogen is often produced on-site, especially at industrial plants and thermal power plants. So aside from any decarbonization efforts, there are many uses for hydrogen which the public appears to be generally unaware of.

This leads us to the somewhat controversial hydrogen ladder.

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