Watching an eclipse from the ground is pretty fun. Depending on where you live, you might even get a decent view. But what if you wanted a truly unique vantage point? You could replicate the work of [Tarik Agcayazi] and [kemfic], who set about filming the recent eclipse from an altitude of 80,000 feet.
That’s what the eclipse looks like from 80,000 feet.
The duo didn’t rent a high-performance aircraft from the US military. Instead, they relied on a high-altitude balloon carrying a glider with a camera payload. The idea was for the balloon to go up, and have the camera capture the eclipse. Then, it would be released so that it could glide back home in controlled flight. However, time constraints made that too hard. Instead, they simplified to a parachute recovery method.
The project video covers the development process, the balloon launch itself, and of course, the filming of the eclipse. High altitude balloon launches are stressful enough, but having a short eclipse as a target made everything even more difficult. But that just makes things more exciting!
The project builds on earlier work from the duo that we discussed back in 2017.
There was a time when real system administrators just logged into Unix systems as root. But as we all know — with great power comes great responsibility. It’s too easy to do terrible things when you are really just trying to do normal work, and, on top of that, malicious software or scripts can do naughty things without you noticing. So common practice quickly changed to where an administrator had a personal account but then had a way to run certain programs “as root” which means you had to deliberately decide to wield your power.
Before long, people realized you don’t even need a root login account. That way, an attacker can’t try to log into root at all. Sure, they could still compromise your account, but a random hacker knows you might have a root user, but it is harder to guess that your login ID is JTKirkJr or whatever.
There are other ways to control what users can do, but many Linux and Unix installations still use this model. The root can do everything but login, and specific users get the privilege to do certain things.
Helicopters are perhaps at their coolest when they’re being used as flying cranes — from a long dangling cable, they can carry everything from cars, to crates, to giant hanging saws.
What you might find altogether more curious are the helicopters that fly around carrying gigantic flat antenna arrays. When you spot one in the field, it’s not exactly intuitive to figure out what they’re doing, but these helicopters are tasked with important geological work!
[Peter Holderith] has been on a mission to unlock the full potential of a DIY quad-motor electric go-kart as a platform. This isn’t his first rodeo, either. His earlier vehicle designs were great educational fun, but were limited to about a kilowatt of power. His current platform is in theory capable of about twenty. The last big change he made was adding considerably more battery power, so that the under-used motors could stretch their legs a little, figuratively speaking.
The keyed stainless steel bracket didn’t stay keyed for long.
One purpose of incremental prototyping is to bring problems to the surface, and it certainly did that. A number of design decisions that were fine on smaller karts showed themselves to be inadequate once the motors had more power.
For one thing, the increased torque meant the motors twisted themselves free from their mountings. The throttle revealed itself to be twitchy with a poor response, and steering didn’t feel very good. The steering got heavier as speed increased, but it also wanted to jerk all over the place. These are profoundly unwelcome feelings when driving a small and powerful vehicle that lurches into motion as soon as the accelerator is pressed.
Overall, one could say the experience populated the proverbial to-do list quite well. The earlier incarnation of [Peter]’s kart was a thrilling ride, but the challenge of maintaining adequate control over a moving platform serves as a reminder that design decisions that do the job under one circumstance might need revisiting in others.
[Markus] grabbed an ESP32 and created a good-looking e-ink dashboard that can act as a status display for Home Automation. However, the hardware is generic enough that it could work as a weather station or even a task scheduler.
The project makes good use of modules, so there isn’t much to build. A Waveshare 2.9-inch e-ink panel and an ESP32, along with a power supply, are all you need. The real work is in the software. Of course, you also need a box to put it in, but with 3D printing, that’s hardly a problem.
Well, it isn’t a problem unless — like [Markus] — you don’t have a 3D printer. Instead, he built a wooden case that also holds notepaper.
The software uses ESPHome to interface with Home Assistant. There is a fair amount of configuration, but nothing too difficult. Of course, you can customize the display to your heart’s content. Overall, this is a great example of how a few modular components and some open-source software can combine to make a very simple yet useful project.
Reaching orbit around Earth is an incredibly difficult feat. It’s a common misconception that getting into orbit just involves getting very high above the ground — the real trick is going sideways very, very fast. Thus far, the most viable way we’ve found to do this is with big, complicated multi-stage rockets that shed bits of themselves as they roar out of the atmosphere.
Single-stage-to-orbit (SSTO) launch vehicles represent a revolutionary step in space travel. They promise a simpler, more cost-effective way to reach orbit compared to traditional multi-stage rockets. Today, we’ll explore the incredible potential offered by SSTO vehicles, and why building a practical example is all but impossible with our current technology.
A Balancing Act
The SSTO concept doesn’t describe any one single spacecraft design. Instead, it refers to any spacecraft that’s capable of achieving orbit using a single, unified propulsion system and without jettisoning any part of the vehicle.
The Saturn V shed multiple stages on its way up to orbit. That way, less fuel was needed to propel the final stage up to orbital velocity. Credit: NASA
Today’s orbital rockets shed stages as they expend fuel. There’s one major reason for this, and it’s referred to as the tyranny of the rocket equation. Fundamentally, a spacecraft needs to reach a certain velocity to attain orbit. Reaching that velocity from zero — i.e. when the rocket is sitting on the launchpad — requires a change in velocity, or delta-V. The rocket equation can be used to figure out how much fuel is required for a certain delta-V, and thus a desired orbit.
The problem is that the mass of fuel required scales exponentially with delta-V. If you want to go faster, you need more fuel. But then you need even more fuel again to carry the weight of that fuel, and so on. Plus, all that fuel needs a tank and structure to hold it, which makes things more difficult again.
Work out the maths of a potential SSTO design, and the required fuel to reach orbit ends up taking up almost all of the launch vehicle’s weight. There’s precious mass left over for the vehicle’s own structure, let alone any useful payload. This all comes down to the “mass fraction” of the rocket. A SSTO powered by even our most efficient chemical rocket engines would require that the vast majority of its mass be dedicated to propellants, with its structure and payload being tiny in comparison. Much of that is due to Earth’s nature. Our planet has a strong gravitational pull, and the minimum orbital velocity is quite high at about 7.4 kilometers per second or so.
Stage Fright
Historically, we’ve cheated the rocket equation through smart engineering. The trick with staged rockets is simple. They shed structure as the fuel burns away. There’s no need to keep hauling empty fuel tanks into orbit. By dropping empty tanks during flight, the remaining fuel on the rocket has to accelerate a smaller mass, and thus less fuel is required to get the final rocket and payload into its intended orbit.
The Space Shuttle sheds its boosters and external fuel tank on its way up to orbit, too. Credit: NASA
So far, staged rockets have been the only way for humanity to reach orbit. Saturn V had five stages, more modern rockets tend to have two or three. Even the Space Shuttle was a staged design: it shed its two booster rockets when they were empty, and did the same with its external liquid fuel tank.
But while staged launch vehicles can get the job done, it’s a wasteful way to fly. Imagine if every commercial flight required you to throw away three quarters of the airplane. While we’re learning to reuse discarded parts of orbital rockets, it’s still a difficult and costly exercise.
The core benefit of a SSTO launch vehicle would be its efficiency. By eliminating the need to discard stages during ascent, SSTO vehicles would reduce launch costs, streamline operations, and potentially increase the frequency of space missions.
Pushing the Envelope
It’s currently believed that building a SSTO vehicle using conventional chemical rocket technology is marginally possible. You’d need efficient rocket engines burning the right fuel, and a light rocket with almost no payload, but theoretically it could be done.
Ideally, though, you’d want a single-stage launch vehicle that could actually reach orbit with some useful payload. Be that a satellite, human astronauts, or some kind of science package. To date there have been several projects and proposals for SSTO launch vehicles, none of which have succeeded so far.
Lockheed explored a spaceplane concept called VentureStar, but it never came to fruition. Credit: NASA
One notable design was the proposed Skylon spacecraft from British company Reaction Engines Limited. Skylon was intended to operate as a reusable spaceplane fueled by hydrogen. It would take off from a runway, using wings to generate lift to help it to ascend to 85,000 feet. This improves fuel efficiency versus just pointing the launch vehicle straight up and fighting gravity with pure thrust alone. Plus, it would burn oxygen from the atmosphere on its way to that altitude, negating the need to carry heavy supplies of oxygen onboard.
Once at the appropriate altitude, it would switch to internal liquid oxygen tanks for the final acceleration phase up to orbital velocity. The design stretches back decades, to the earlier British HOTOL spaceplane project. Work continues on the proposed SABRE engine (Syngergetic Air-Breathing Rocket Engine) that would theoretically propel Skylon, though no concrete plans to build the spaceplane itself exist.
The hope was that efficient aerospike rocket engines would let the VentureStar reach orbit in a single stage.
Lockheed Martin also had the VentureStar spaceplane concept, which used an innovative “aerospike” rocket engine that maintained excellent efficiency across a wide altitude range. The company even built a scaled-down test craft called the X-33 to explore the ideas behind it. However, the program saw its funding slashed in the early 2000s, and development was halted.
McDonnell Douglas also had a crack at the idea in the early 1990s. The DC-X, also known as the Delta Clipper, was a prototype vertical takeoff and landing vehicle. At just 12 meters high and 4.1 meters in diameter, it was a one-third scale prototype for exploring SSTO-related technologies
It would take off vertically like a traditional rocket, and return to Earth nose-first before landing on its tail. The hope was that the combination of single-stage operation and this mission profile would provide extremely quick turnaround times for repeat launches, which was seen as a boon for potential military applications. While its technologies showed some promise, the project was eventually discontinued when a test vehicle caught fire after NASA took over the project.
McDonnell Douglas explored SSTO technologies with the Delta Clipper. Credit: Public domain
Ultimately, a viable SSTO launch vehicle that can carry a payload will likely be very different from the rockets we use today. Relying on wings to generate lift could help save fuel, and relying on air in the atmosphere would slash the weight of oxidizer that would have to be carried onboard.
However, it’s not as simple as just penning a spaceplane with an air-breathing engine and calling it done. No air breathing engine that exists can reach orbital velocity, so such a craft would need an additional rocket engine too, adding weight. Plus, it’s worth noting a reusable launch vehicle would also still require plenty of heat shielding to survive reentry. One could potentially build a non-reusable single-stage to orbit vehicle that simply stays in space, of course, but that would negate many of the tantalizing benefits of the whole concept.
Single-stage-to-orbit vehicles hold the promise of transforming how we access space by simplifying the architecture of launch vehicles and potentially reducing costs. While there are formidable technical hurdles to overcome, the ongoing advances in aerospace technology provide hope that SSTO could become a practical reality in the future. As technology marches forward in materials, rocketry, and aerospace engineering in general, the dream of a single-stage path to orbit remains a tantalizing future goal.
When something does zero-shot image classification, that means it’s able to make judgments about the contents of an image without the user needing to train the system beforehand on what to look for. Watch it in action with this online demo, which uses WebGPU to implement CLIP (Contrastive Language–Image Pre-training) running in one’s browser, using the input from an attached camera.
By giving the program some natural language visual concept labels (such as ‘person’ or ‘cat’) that fit a hypothetical template for the image content, the system will output — in real-time — its judgement on the appropriateness of such labels to what the camera sees. Again, all of this runs locally.
It’s maybe a little bit unintuitive, but what’s happening in the demo is that the system is deciding which of the user-provided labels (“a photo of a cat” vs “a photo of a bald man”, for example) is most appropriate to what the camera sees. The more a particular label is judged a good fit for the image, the higher the number beside it.
This kind of process benefits greatly from shoveling the hard parts of the computation onto compatible graphics cards, which is exactly what WebGPU provides by allowing the browser access to a local GPU. WebGPU is relatively recent, but we’ve already seen it used to run LLMs (Large Language Models) directly in the browser.
