Space

589 Articles

Flirting With Kessler: Why Space Debris Physics Make It Such An Orbital Pain

November 5, 2024 by 37 Comments

Picture in your mind a big parking lot with 131 million cars on it. Now imagine that they are spread out over the entire Earth’s inhabited areas. Although still a large number, it is absolutely dwarfed by the approximately 1.47 billion cars registered and in use today, with room to spare for houses, parks and much more. The 131 million represents the total number of known and estimated space debris objects in Earth orbit sized 1 mm and up, as per the European Space Agency. This comes on top of the approximately 13,200 satellites still in Earth orbit of which 10,200 are still functional.

Now imagine that most of these 131 million cars of earlier are sized 10 cm or smaller. Spaced out across the Earth’s entire surface you’d not be able to see more than at most one. Above the Earth’s surface there are many orbital planes and no pesky oceans to prevent millimeter and centimeter-sized cars from being spaced out there. This gives a rough idea of just how incredibly empty Earth’s orbital planes are and why from the International Space Station you rarely notice any such space debris until a small bit slams into a solar panel or something equally not amusing.

Cleaning up space debris seems rather unnecessary in this perspective, except that even the tiniest chunk travels at orbital velocities of multiple kilometers per second with kinetic energy to spare. Hence your task: to chase down sub-10 cm debris in hundreds of kilometers of mostly empty orbital planes as it zips along with destructive intent. Surely this cannot be so difficult with lasers on the ISS or something?

Continue reading “Flirting With Kessler: Why Space Debris Physics Make It Such An Orbital Pain” →

Voyager 1 Fault Forces Switch To S-Band

October 31, 2024 by 70 Comments

We hate to admit it, but whenever we see an article about either Voyager spacecraft, our thoughts immediately turn to worst-case scenarios. One of these days, we’ll be forced to write obituaries for the plucky interstellar travelers, but today is not that day, even with news of yet another issue aboard Voyager 1 that threatens its ability to communicate with Earth.

According to NASA, the current problem began on October 16 when controllers sent a command to turn on one of the spacecraft’s heaters. Voyager 1, nearly a light-day distant from Earth, failed to respond as expected 46 hours later. After some searching, controllers picked up the spacecraft’s X-band downlink signal but at a much lower power than expected. This indicated that the spacecraft had gone into fault protection mode, likely in response to the command to turn on the heater. A day later, Voyager 1 stopped communicating altogether, suggesting that further fault protection trips disabled the powerful X-band transmitter and switched to the lower-powered S-band downlink.

This was potentially mission-ending; the S-band downlink had last been used in 1981 when the probe was still well within the confines of the solar system, and the fear was that the Deep Space Network would not be able to find the weak signal. But find it they did, and on October 22 they sent a command to confirm S-band communications. At this point, controllers can still receive engineering data and command the craft, but it remains to be seen what can be done to restore full communications. They haven’t tried to turn the X-band transmitter back on yet, wisely preferring to further evaluate what caused the fault protection error that kicked this whole thing off before committing to a step like that.

Following Voyager news these days feels a little morbid, like a death watch on an aging celebrity. Here’s hoping that this story turns out to have a happy ending and that we can push the inevitable off for another few years. While we wait, if you want to know a little more about the Voyager comms system, we’ve got a deep dive that should get you going.

Thanks to [Mark Stevens] for the tip.

Video Provides Rare Look Inside China’s Space Station

October 28, 2024 by 71 Comments

China has a space station — it’s called Tiangong, the first module was launched in 2021, and it’s all going quite swimmingly, thank you very much. That’s essentially what we know about the orbital complex here in the West, as China tends to be fairly secretive when it comes to their activities in space.

But thanks to a recently released video by the state-funded CCTV Video News Agency, we now have an unprecedented look inside of humanity’s newest orbital laboratory. Shenzhou-18 crew members [Ye Guangfu], [Li Cong], and [Li Guangsu] provide viewers with a full-blown tour of the station, and there’s even baked-in English subtitles so you won’t miss a beat.

The few looks the public has gotten inside of Tiangong in the past have been low-resolution and generally of the “shaky cam” variety. In comparison, this flashy presentation was clearly made to impress an international audience. But let’s be fair, if you managed to build your own crewed station in low Earth orbit, wouldn’t you want to show it off a bit? Continue reading “Video Provides Rare Look Inside China’s Space Station” →

Clockwork Rover For Venus

October 26, 2024 by 28 Comments

Venus hasn’t received nearly the same attention from space programs as Mars, largely due to its exceedingly hostile environment. Most electronics wouldn’t survive the 462 °C heat, never mind the intense atmospheric pressure and sulfuric acid clouds. With this in mind, NASA has been experimenting with the concept of a completely mechanical rover. The [Beardy Penguin] and a team of fellow students from the University of Southampton decided to try their hand at the concept—video after the break.

The project was divided into four subsystems: obstacle detection, mechanical computer, locomotion (tracks), and the drivetrain. The obstacle detection system consists of three (left, center, right) triple-rollers in front of the rover, which trigger inputs on the mechanical computer when it encounters an obstacle over a certain size. The inputs indicate the position of each roller (up/down) and the combination of inputs determines the appropriate maneuver to clear the obstacle. [Beardy Penguin] used Simulink to design the logic circuit, consisting of AND, OR, and NOT gates. The resulting 5-layer mechanical computer quickly ran into the limits of tolerances and friction, and the team eventually had trouble getting their design to work with the available input forces.

Due to the high-pressure atmosphere, an on-board wind turbine has long been proposed as a viable power source for a Venus rover. It wasn’t part of this project, so it was replaced with a comparable 40 W electric motor. The output from a logic circuit goes through a timing mechanism and into a planetary gearbox system. It changes output rotation direction by driving the planet gear carrier with the sun gear or locking it in a stationary position.

As with many undergraduate engineering projects, the physical results were mixed, but the educational value was immense. They got individual subsystems working, but not the fully integrated prototype. Even so, they received several awards for their project and even came third in an international Simulink challenge. It also allowed another team to continue their work and refine the subsystems. Continue reading “Clockwork Rover For Venus” →

Libre Space Foundation Aims To Improve Satellite Tech

October 22, 2024 by 27 Comments

There’s no shortage of movies, TV shows, and books that show a dystopian future with corporations run amok in outer space with little or no effective oversight. Dune, The Expanse, and The Dispossessed spring to mind as predicting different aspects of this idea, but there are plenty of other warnings throughout sci-fi depicting this potential future. One possible way of preventing this outcome is by ensuring that space is as open-sourced as possible and one group, the Libre Space Foundation (LSF), is working towards this end. Their latest is a project with Ondsel to develop and model a satellite deploying mechanism using almost entirely open source software.

The LSF had already designed the PICOBUS satellite launcher system that flew to space in 2022 and deployed a number of CubeSats, but the group needed more information about how the system would perform. They turned to Ondsel to help develop a multi-body dynamics (MBD) solver, managing simulations with mass-spring-damper models. The satellite launcher includes a large constant-force spring that pushes the CubeSats out of the device once the door is opened, and the model can now simulate their paths in space without gravity. The team will launch their next set of satellites sometime next year on an RFA-ONE rocket.

The LSF maintains a huge database of their open source space projects, including this one, on their GitLab page. Although it might seem like small potatoes now, the adoption of open source software and hardware by space-fairing entities can help further the democratization of low Earth orbit.

Thanks to [johnad] for the tip!

Cockroaches In Space: Waste Processing And A Healthy Protein Source Combined

October 12, 2024 by 51 Comments

As the current frontier of humanity in space, the International Space Station is heavily reliant on Earth not only for fresh supplies but also as a garbage disposal service for the various types of waste produced on the ISS by its human occupants. As future manned missions take humans further away from Earth, finding ways to reprocess this waste rather than chucking it out of the nearest airlock becomes a priority. One suggested solution comes from a Polish company, Astronika, with their insect bioreactor that can process organic material into useful biomass.

Interestingly, the cockroach species picked was the Madagascar hissing cockroach, one of the largest (5 – 7.5 cm) species. This is also a cockroach species which is often kept as a pet. In this closed-loop bioreactor that Astronika has developed, these cockroaches would chew their way through up to 3.6 kg of waste per week in the large version, with the adult cockroaches presumably getting turned into fresh chow and various materials at some point. Beyond the irrational ‘yuck’ factor that comes with eating insect protein, one of the biggest issues we can see with this system is that the long-duration mission crew may get attached to the cockroaches, as they are rather cute.

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Supercon 2023: Receiving Microwave Signals From Deep-Space Probes

October 10, 2024 by 5 Comments

Here’s the thing about radio signals. There is wild and interesting stuff just getting beamed around all over the place. Phrased another way, there are beautiful signals everywhere for those with ears to listen. We go about our lives oblivious to most of them, but some dedicate their time to teasing out and capturing these transmissions.

David Prutchi is one such person. He’s a ham radio enthusiast that dabbles in receiving microwave signals sent from probes in deep space. What’s even better is that he came down to Supercon 2023 to tell us all about how it’s done!

Continue reading “Supercon 2023: Receiving Microwave Signals From Deep-Space Probes” →