Ask Hackaday: Where Are All The Fuel Cells?

August 21, 2025 by 60 Comments

Given all the incredible technology developed or improved during the Apollo program, it’s impossible to pick out just one piece of hardware that made humanity’s first crewed landing on another celestial body possible. But if you had to make a list of the top ten most important pieces of gear stacked on top of the Saturn V back in 1969, the fuel cell would have to place pretty high up there.

Apollo fuel cell. Credit: James Humphreys

Smaller and lighter than batteries of the era, each of the three alkaline fuel cells (AFCs) used in the Apollo Service Module could produce up to 2,300 watts of power when fed liquid hydrogen and liquid oxygen, the latter of which the spacecraft needed to bring along anyway for its life support system. The best part was, as a byproduct of the reaction, the fuel cells produced drinkable water.

The AFC was about as perfectly suited to human spaceflight as you could get, so when NASA was designing the Space Shuttle a few years later, it’s no surprise that they decided to make them the vehicle’s primary electrical power source. While each Orbiter did have backup batteries for emergency purposes, the fuel cells were responsible for powering the vehicle from a few minutes before launch all the way to landing. There was no Plan B. If an issue came up with the fuel cells, the mission would be cut short and the crew would head back home — an event that actually did happen a few times during the Shuttle’s 30 year career.

This might seem like an incredible amount of faith for NASA to put into such a new technology, but in reality, fuel cells weren’t really all that new even then. The space agency first tested their suitability for crewed spacecraft during the later Gemini missions in 1965, and Francis Thomas Bacon developed the core technology all the way back in 1932.

So one has to ask…if fuel cell technology is nearly 100 years old, and was reliable and capable enough to send astronauts to the Moon back in 1960s, why don’t we see them used more today?

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How To Sink A Ship: Preparing The SS United States For Its Final Journey

August 19, 2025 by 82 Comments

When we last brought you word of the SS United States, the future of the storied vessel was unclear. Since 1996, the 990 foot (302 meter) ship — the largest ocean liner ever to be constructed in the United States — had been wasting away at Pier 82 in Philadelphia. While the SS United States Conservancy was formed in 2009 to support the ship financially and attempt to redevelop it into a tourist attraction, their limited funding meant little could be done to restore or even maintain it. In January of 2024, frustrated by the lack of progress, the owners of the pier took the Conservancy to court and began the process of evicting the once-great liner.

SS United States docked at Pier 82 in Philadelphia

It was hoped that a last-minute investor might appear, allowing the Conservancy to move the ship to a new home. But unfortunately, the only offer that came in wasn’t quite what fans of the vessel had in mind: Florida’s Okaloosa County offered $1 million to purchase the ship so they could sink it and turn it into the world’s largest artificial reef.

The Conservancy originally considered it a contingency offer, stating that they would only accept it if no other options to save the ship presented themselves. But by October of 2024, with time running out, they accepted Okaloosa’s offer as a more preferable fate for the United States than being scrapped.

It at least means the ship will remain intact — acting not only as an important refuge for aquatic life, but as a destination for recreational divers for decades to come. The Conservancy has also announced plans to open a museum in Okaloosa, where artifacts from the ship will be on display.

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The Terminal Demise Of Consumer Electronics Through Subscription Services

August 18, 2025 by 87 Comments

Open any consumer electronics catalog from around the 1980s to the early 2000s and you are overwhelmed by a smörgåsbord of devices, covering any audio-visual and similar entertainment and hobby needs one might have. Depending on the era you can find the camcorders, point-and-shoot film and digital cameras right next to portable music players, cellphones, HiFi sets and tower components, televisions and devices like DVD players and VCRs, all of them in a dizzying amount of brands, shapes and colors that are sure to fit anyone’s needs, desires and budget.

When by the late 2000s cellphones began to absorb more and more of the features of these devices alongside much improved cellular Internet access, these newly minted ‘smartphones’ were hailed as a technological revolution that combined so many consumer electronics into a single device. Unlike the relatively niche feature phones, smartphones absolutely took off.

Fast-forward more than a decade and the same catalogs now feature black rectangles identified respectively as smart phones, smart TVs and tablets, alongside evenly colored geometric shapes that identify as smart speakers and other devices. While previously the onus for this change was laid by this author primarily on the death of industrial design, the elephant in the room would seem to be that consumer electronics are suffering from a terminal disease: subscription services.

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That’s No Moon, Er, Selectric

August 12, 2025 by 5 Comments

If you learned to type anytime in the mid-part of the 20th century, you probably either had or wanted an IBM Selectric. These were workhorses and changed typing by moving from typebars to a replaceable element. They were expensive, though worth it since many of them still work (including mine). But few of us could afford the $1,000 or more that these machines cost back in the day, especially when you consider that $1,000 was enough to buy a nice car for most of that time. [Tech Tangents] looks at something different: a clone Selectric from the sewing machine and printer company Juki.

The typewriter was the brainchild of [Thomas O’Reilly]. He sold typewriters and knew that a $500 compatible machine would sell. He took the prototype to Juki, which was manufacturing typewriters for Olivetti at the time.

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A History Of Pong

July 28, 2025 by 8 Comments

Today, creating a ground-breaking video game is akin to making a movie. You need a story, graphic artists, music, and more. But until the middle of the 20th century, there were no video games. While several games can claim to be the “first” electronic or video game, one is cemented in our collective memory as the first one we’d heard of: Pong.

The truth is, Pong wasn’t the first video game. We suspect that many people might have had the idea, but Ralph Baer is most associated with inventing a practical video game. As a young engineer in 1951, he tried to convince his company to invest in games that you could play on your TV set. They didn’t like the idea, but Ralph would remember the concept and act on it over a decade later.

But was it really the first time anyone had thought of it? Perhaps not. Thomas Goldsmith Jr. and Estle Ray Mann filed a patent in 1947 for a game that simulated launching missiles at targets with an oscilloscope display. The box took eight tubes and, being an oscilloscope, was a vector graphic device. The targets were physical dots on a screen overlay. These “amusement devices” were very expensive, and they only produced handmade prototypes.

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Commodore 64 On New FPGA

July 28, 2025 by 19 Comments

When it comes to getting retro hardware running again, there are many approaches. On one hand, the easiest path could be to emulate the hardware on something modern, using nothing but software to bring it back to life. On the other, many prefer to restore the original hardware itself and make sure everything is exactly as it was when it was new. A middle way exists, though, thanks to the widespread adoption of FPGAs which allow for programmable hardware emulation and [Jo] has come up with a new implementation of the Commodore 64 by taking this path.

The project is called the VIC64-T9K and is meant as a proof-of-concept that can run the Commodore 64’s VIC-II video chip alongside a 6502 CPU on the inexpensive Tang Nano 9k FPGA. Taking inspiration from the C64_MiSTer project, another FPGA implementation of the C64 based on the DE10-Nano FPGA, it doesn’t implement everything an original Commodore system would have had, but it does provide most of the core hardware needed to run a system. The project supports HDMI video with a custom kernel, and [Jo] has used it to get a few demos running including sprite animations.

Built with a mix of Verilog and VHDL, it was designed as a learning tool for [Jo] to experiment with the retro hardware, and also brings a more affordable FPGA board to the table for Commodore enthusiasts. If you’re in the market for something with more of the original look and feel of the Commodore 64, though, this project uses the original case and keyboard while still using an FPGA recreation for the core of the computer.

Experience Other Planets With The Gravity Simulator

July 27, 2025 by 8 Comments

As Earthlings, most of us don’t spend a lot of extra time thinking about the gravity on our home planet. Instead, we go about our days only occasionally dropping things or tripping over furniture but largely attending to other matters of more consequence. When humans visit other worlds, though, there’s a lot more consideration of the gravity and its effects on how humans live and many different ways of training for going to places like the Moon or Mars. This gravity simulator, for example, lets anyone experience what it would be like to balance an object anywhere with different gravity from Earth’s.

The simulator itself largely consists of a row of about 60 NeoPixels, spread out in a line along a length of lightweight PVC pipe. They’re controlled by an Arduino Nano which has a built-in inertial measurement unit, allowing it to sense the angle the pipe is being held at as well as making determinations about its movement. A set of LEDs on the NeoPixel strip is illuminated, which simulates a ball being balanced on this pipe, and motion one way or the other will allow the ball to travel back and forth along its length. With the Earth gravity setting this is fairly intuitive but when the gravity simulation is turned up for heavier planets or turned down for lighter ones the experience changes dramatically. Most of the video explains the math behind determining the effects of a rolling ball in each of these environments, which is worth taking a look at on its own.

While the device obviously can’t change the mass or the force of gravity by pressing a button, it’s a unique way to experience and feel what a small part of existence on another world might be like. With enough budget available there are certainly other ways of providing training for other amounts of gravity like parabolic flights or buoyancy tanks, although one of the other more affordable ways of doing this for laypeople is this low-gravity acrobatic device.

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