Attack Of The Atomic Oxygen

While designing anything for operation in space has its challenges, there is at least one thing that is more of a problem for objects in Earth orbit than for deep-space probes: atomic oxygen. We like oxygen because we need it to live, but it is also highly reactive as a single atom. Luckily, on Earth, most of what we breathe is O2. [Space Daily] talks about the challenges of the International Space Station dealing with the “space weather” of atomic oxygen in low Earth orbit.

Part of the problem is that even when we know better, we tend to think of the atmosphere coming to an abrupt end and space being a hard vacuum. But in reality, the atmosphere gradually dissipates, and at “only” 400 km above the Earth, the Space Station is really flying through a very thin atmosphere.

To compound the problem, this is above the ozone layer, so the Sun’s UV light rips O2 into single oxygen atoms. Over time, these free oxygen atoms can affect many parts of a spacecraft exposed to them. Engineers first noticed that materials recovered from spacecraft had more damage and changes to material properties on the pieces facing the direction of travel. NASA has spent years testing different materials by mounting trays of different material samples outside the ISS.

Carbon-based polymers take a big hit from atomic oxygen exposure. Polymide film is frequently used, but it erodes with exposure. Carbon composites also lose mass. Other materials change in other ways. For example, an optical surface may roughen with exposure.

The usual answer is to over-design for mission objectives or to cover certain polymers with coatings like silicon dioxide or aluminum oxide, which are not as reactive to free oxygen. For a long-duration mission like the ISS, you may have to pay special attention to the materials in use. Very low satellites also need special care, as there is more oxygen in lower orbits.

There are other effects, too, such as extreme thermal cycles, debris strikes, and other indignities that space-traveling materials must withstand. But in deep space, atomic oxygen is a rare issue. Until, at least, we go somewhere else that has a lot of oxygen.

Hackaday Links Column Banner

Hackaday Links: March 29, 2026

Whether it’s a new couch or a rare piece of hardware picked up on eBay, we all know what it feels like to eagerly await a delivery truck. But the CERN researchers involved in a delivery earlier this week weren’t transporting anyone’s Amazon Prime packages, they were hauling antimatter.

Moving antimatter, specifically antiprotons, via trucks might seem a bit ridiculous. But ultimately CERN wants to transfer samples between various European laboratories, and that means they need a practical and reliable way of getting the temperamental stuff from point A to B. To demonstrate this capability, the researchers loaded a truck with 92 antiprotons and drove it around for 30 minutes. Of course, you can’t just put antiprotons in a cardboard box, the experiment utilized a cryogenically cooled magnetic containment unit that they hope will eventually be able to keep antimatter from rudely annihilating itself on trips lasting as long as 8 hours.

Speaking of deliveries, anyone building a new computer should be careful when ordering components. Shady companies are looking to capitalize on the currently sky high prices of solid-state drives by counterfeiting popular models, and according to the Japanese site AKIBA PC Hotline, there are some examples in the wild that would fool  all but the most advanced users. They examine a bootleg drive that’s a nearly identical replica of the Samsung 990 PRO —  the unit and its packaging are basically a mirror image of the real deal, the stated capacity appears valid, and it even exhibits similar performance when put through a basic benchmark test.

Continue reading “Hackaday Links: March 29, 2026”

Real-Time ISS Tracker Shows Off The Goods

What hardware hacker doesn’t have a soft spot for transparent cases? While they may have fallen out of mainstream favor, they have an undeniable appeal to anyone with an interest in electronic or mechanical devices. Which is why the Orbigator built by [wyojustin] stands out among similar desktop orbital trackers we’ve seen.

Conceptually, it’s very similar to the International Space Station tracking lamp that [Will Dana] built in 2025. In fact, [wyojustin] cites it specifically as one of the inspirations for this project. But unlike that build, which saw a small model of the ISS moving across the surface of the globe, a transparent globe is rotated around the internal mechanism. This not only looks gorgeous, but solves a key problem in [Will]’s design — that is, there’s no trailing servo wiring that needs to be kept track of.

For anyone who wants an Orbigator of their own, [wyojustin] has done a fantastic job of documenting the hardware and software aspects of the build, and all the relevant files are available in the project’s GitHub repository.

The 3D printable components have been created with OpenSCAD, the firmware responsible for calculating the current position of the ISS on the Raspberry Pi Pico 2 is written in MicroPython, and the PCB was designed in KiCad. Incidentally, we noticed that Hackaday alum [Anool Mahidharia] appears to have been lending a hand with the board design.

As much as we love these polished orbital trackers, we’ve seen far more approachable builds if you don’t need something so elaborate. If you’re more interested in keeping an eye out for planes and can get your hands on a pan-and-tilt security camera, it’s even easier.

ISS Medical Emergency: An Orbital Ambulance Ride

Over the course of its nearly 30 years in orbit, the International Space Station has played host to more “firsts” than can possibly be counted. When you’re zipping around Earth at five miles per second, even the most mundane of events takes on a novel element. Arguably, that’s the point of a crewed orbital research complex in the first place — to study how humans can live and work in an environment that’s so unimaginably hostile that something as simple as eating lunch requires special equipment and training.

Today marks another unique milestone for the ISS program, albeit a bittersweet one. Just a few hours ago, NASA successfully completed the first medical evacuation from the Station, cutting the Crew-11 mission short by at least a month. By the time this article is released, the patient will be back on terra firma and having their condition assessed in California. This leaves just three crew members on the ISS until NASA’s Crew-12 mission can launch in early February, though it’s possible that mission’s timeline will be moved up.

Continue reading “ISS Medical Emergency: An Orbital Ambulance Ride”

Testing The Survivability Of Moss In Space

The cool part about science is that you can ask questions like what happens if you stick some moss spores on the outside of the International Space Station, and then get funding for answering said question. This was roughly the scope of the experiment that [Chang-hyun Maeng] and colleagues ran back in 2022, with their findings reported in iScience.

Used as moss specimen was Physcomitrium patens, a very common model organism. After previously finding during Earth-based experiments that the spores are the most resilient, these were subsequently transported to the ISS where they found themselves placed in the exposure unit of the Kibo module. Three different exposure scenarios were attempted for the spores, with all exposed to space, but one set kept in the dark, another protected from UV and a third set exposed to the healthy goodness of the all-natural UV that space in LEO has to offer.

After the nine month exposure period, the spores were transported back to Earth, where the spores were allowed to develop into mature P. patens moss. Here it was found that only the spores which had been exposed to significant UV radiation – including UV-C unfiltered by the Earth’s atmosphere – saw a significant reduction in viability. Yet even after nine months of basking in UV-C, these still had a germination rate of 86%, which provides fascinating follow-up questions regarding their survivability mechanisms when exposed to UV-C as well as a deep vacuum, freezing temperatures and so on.

A New Generation Of Spacecraft Head To The ISS

While many in the industry were at first skeptical of NASA’s goal to put resupply flights to the International Space Station in the hands of commercial operators, the results speak for themselves. Since 2012, the SpaceX Dragon family of spacecraft has been transporting crew and cargo from American soil to the orbiting laboratory, a capability that the space agency had lost with the retirement of the Space Shuttle. Putting these relatively routine missions in the hands of a commercial provider like SpaceX takes some of the logistical and financial burden off of NASA, allowing them to focus on more forward-looking projects.

SpaceX Dragon arriving at the ISS for the first time in 2012.

But as the saying goes, you should never put all of your eggs in one basket. As successful as SpaceX has been, there’s always a chance that some issue could temporarily ground either the Falcon 9 or the Dragon.

While Russia’s Progress and Soyuz vehicles would still be available in an emergency situation, it’s in everyone’s best interest that there be multiple backup vehicles that can bring critical supplies to the Station.

Which is precisely why several new or upgraded spacecraft, designed specifically for performing resupply missions to the ISS and any potential commercial successor, are coming online over the next few years.

In fact, one of them is already flying its first mission, and will likely have arrived at the International Space Station by the time you read this article.

Continue reading “A New Generation Of Spacecraft Head To The ISS”

Dragon Is The Latest, And Final, Craft To Reboost ISS

The International Space Station has been in orbit around the Earth, at least in some form, since November of 1998 — but not without help. In the vacuum of space, an object in orbit can generally be counted on to remain zipping around more or less forever, but the Station is low enough to experience a bit of atmospheric drag. It isn’t much, but it saps enough velocity from the Station that without regular “reboosts” to speed it back up , the orbiting complex would eventually come crashing down.

Naturally, the United States and Russia were aware of this when they set out to assemble the Station. That’s why early core modules such as Zarya and Zvezda came equipped with thrusters that could be used to not only rotate the complex about all axes, but accelerate it to counteract the impact of drag. Eventually the thrusters on Zarya were disabled, and its propellant tanks were plumbed into Zvezda’s fuel system to provide additional capacity.

An early image of ISS, Zarya module in center and Zvezda at far right.

Visiting spacecraft attached to the Russian side of the ISS can transfer propellant into these combined tanks, and they’ve been topped off regularly over the years. In fact, the NASA paper A Review of In-Space Propellant Transfer Capabilities and Challenges for Missions Involving Propellant Resupply, notes this as one of the most significant examples of practical propellant transfer between orbital vehicles, with more than 40,000 kgs of propellants pumped into the ISS as of 2019.

But while the thrusters on Zvezda are still available for use, it turns out there’s an easier way to accelerate the Station; visiting spacecraft can literally push the orbital complex with their own maneuvering thrusters. Of course this is somewhat easier said than done, and not all vehicles have been able to accomplish the feat, but over the decades several craft have taken on the burden of lifting the ISS into a higher orbit.

Earlier this month, a specially modified SpaceX Cargo Dragon became the newest addition to the list of spacecraft that can perform a reboost. The craft will boost the Station several times over the rest of the year, which will provide valuable data for when it comes time to reverse the process and de-orbit the ISS in the future.

Continue reading “Dragon Is The Latest, And Final, Craft To Reboost ISS”