Space

663 Articles

Water On Mars? Maybe Not

November 24, 2025 by 9 Comments

We were as excited as anyone when MARSIS (the Mars Advanced Radar for Subsurface and Ionosphere Sounding) experiment announced there was possibly liquid water under the southern polar ice cap. If there is liquid water on Mars, it would make future exploration and colonization much more feasible. Unfortunately, SHARAD (the Shallow Radar) has a new trick that suggests the data may not indicate liquid water after all.

While the news is a bummer, the way scientists used SHARAD to confirm — or, in this case, deny — the water hypothesis was a worthy hack. The SHARAD antenna is on the Mars Reconnaissance Orbiter, but in a position that makes it difficult to obtain direct surface readings from Mars. To compensate, operators typically roll the spacecraft to give the omnidirectional antenna a clearer view of the ground. However, those rolls have been under 30 degrees.

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Testing The Survivability Of Moss In Space

November 24, 2025 by 10 Comments

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.

The King Of Rocket Photography

November 16, 2025 by 27 Comments

If you are a nerdy kid today, you have your choice of wondrous gadgets and time wasters. When we were nerdy kids, our options were somewhat limited: there was ham radio, or you could blow things up with a chemistry set. There were also model rockets. Not only were model rockets undeniably cool, but thanks to a company called Estes, you could find ready-to-go kits and gear that made it possible to launch something into the heavens, relatively speaking. But what about photographic proof? No live streams or digital cameras. But there was the Estes AstroCam 100. [Bill Engar] remembers the joy of getting film from your rocket developed.

Of course, photography was another nerdy kid staple, so maybe you did your own darkroom work. Either way, the Astrocam 110 was a big improvement over the company’s earlier Camroc. In 1965, if you wanted to fly Camroc, you had to cut a 1.5-inch piece of film in a darkroom and mount it just to get one terrible black-and-white photo. Or, you could buy the film canisters loaded if you had the extra money, which, of course, you didn’t.

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Radio Astronomy In The Palm Of Your Hand

October 17, 2025 by 5 Comments

When you think of a radio telescope, you usually think of a giant dish antenna pointing skyward. But [vhuvanmakes] built Wavy-Scope, a handheld radio telescope that can find the Sun and the Moon, among other things.

The build is relatively straightforward, using a commercial LNB to detect signals in the 10-12 GHz range. The detector is a simple satellite finder, although you could also connect it to a software-defined radio, if you wanted something more sophisticated.

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Building The LEM’s Legs

October 13, 2025 by 13 Comments

If you built a car in, say, Germany, for use in Canada, you could assume that the roads will be more or less the same. Gravity will work the same. While the weather might not be exactly the same, it won’t be totally different. But imagine designing the Lunar Excursion Module that would land two astronauts on the moon for the first time. No one had any experience landing a craft on any alien body before.

The LEM was amazing for many reasons, but as [Apollo11Space] points out, the legs were a particularly thorny engineering problem. They had to land on mostly unknown terrain, stay upright, allow for the ascent module to take off again, and, of course, not weigh down the tiny spaceship. They also had to survive the blast of the LEM’s engine.

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A Cut Above: Surgery In Space, Now And In The Future

September 30, 2025 by 3 Comments

In case you hadn’t noticed, we live in a dangerous world. While our soft, fleshy selves are remarkably good at absorbing kinetic energy and healing the damage that results, there are very definite limits to what we humans can deal with, beyond which we’ll need some help. Car crashes, falls from height, or even penetrating trauma such as gunshot wounds — events such as these will often land you in a trauma center where, if things are desperate enough, you’ll be on the operating table within the so-called “Golden Hour” of maximum survivability, to patch the holes and plug the leaks.

While the Golden Hour may be less of a hard limit than the name implies, it remains true that the sooner someone with a major traumatic injury gets into surgery, the better their chances of survival. Here on planet Earth, most urban locations can support one or more Level 1 trauma centers, putting huge swathes of the population within that 60-minute goal. Even in rural areas, EMS systems with Advanced Life Support crews can stabilize the severely wounded until they can be evacuated to a trauma center by helicopter, putting even more of the population within this protective bubble.

But ironically, residents in the highest-priced neighborhood in human history enjoy no such luxury. Despite only being the equivalent of a quick helicopter ride away, the astronauts and cosmonauts aboard the International Space Station are pretty much on their own when it comes to any traumatic injuries or medical emergencies that might crop up in orbit. While the ISS crews are well-prepared for that eventuality, as we’ll see, there’s only so much we can do right now, and we have a long way to go before we’re ready to perform surgery in space

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Diagram of an air-breathing satellite

It’s A Bird! It’s A Plane! It’s… An Air Breathing Satellite?!

September 24, 2025 by 18 Comments

The big problem with Low Earth Orbit is, oddly enough, air resistance. Sure, there’s not enough air to breathe in space, but there is enough to create drag when you’re whipping around the planet at 28,000 km/h (17,000 mph) or more. Over time, that adds up to a decaying orbit. [Eager Space] recently did a video summarizing a paradoxical solution: go even lower, and let the air work for you.

So called air-breathing satellites would hang out in very low earth orbit– still well above the Karman line, but below 300 km (186 miles)– where atmospheric drag is too dominant for the current “coast on momentum” satellite paradigm to work. There are advantages to going so low, chiefly for communications (less latency) and earth observation (higher resolutions). You just need to find a way to fight that drag and not crash within a couple of orbits.

It turns out this space isn’t totally empty (aside from the monoatomic oxygen) as missions have been at very low orbits using conventional, Xenon-fueled ion engines to counter drag. The xenon runs out pretty quick in this application, though, and those satellites all had fairly short lifetimes.

That’s where the air-breathing satellites come in. You don’t need a lot of thrust to stabilize against drag, after all, and the thin whisps of air at 200 km or 300 km above ground level should provide ample reaction mass for some kind of solar-electric ion engine. The devil is in the details, of course, and [Eager Space] spends 13 minutes discussing challenges (like corrosive monoatomic oxygen) and various proposals.

Whoever is developing these satellites, they could do worse than talk to [Jay Bowles], whose air-breathing ion thrusters have been featured here several times over the years.

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