Space

705 Articles

Figuring Out What James Webb’s Mysterious Little Red Dots Are

May 26, 2026 by 16 Comments

After the James Webb Space Telescope (JWST) began operations in 2022, it soon made a tantalizing discovery in the form of mysterious red dots: small, red-tinted astronomical objects of unknown origin and composition. So far well over 300 of such little red dots (LRDs) have been identified, with many theories on what they are. Fortunately the Chandra X-ray Observatory recently added some more clues as detailed in an accompanying paper.

Current theories include them being a form of primordial galaxy, or a supermassive black holes embedded in a dense gas cloud. The LRD discussed in the paper with the designation 3DHST-AEGIS-12014 was found to emit X-rays unlike other LRDs. By comparing the data between JWST and Chandra for this LRD it lends credence to the theory that these LRDs are a transitional phase as a supermassive black hole ingests the material of said gas cloud.

X-rays produced during this can sometimes make it out of the gas cloud, after which we can observe it. If that’s the case, these LRDs should cease to exist the moment the black hole has consumed enough of the cloud, which is something that we may be able to find evidence for if we’re lucky.

This adds just another reason why keeping the Chandra X-ray Observatory mission funded, after it narrowly got saved in 2024.

Spacelab’s Mitra 125 MS

May 24, 2026 by 4 Comments

[Ken Shirriff] does some of the most interesting teardowns. This time, he’s looking at a French-built minicomputer called the Mitra 125 MS from around 1980. In particular, it was the computer inside Spacelab, a European lab that could fit in the back of the Space Shuttle.

As you might expect, the computer doesn’t contain a microprocessor. Instead, it is a series of cards and, in this post, [Ken’s] looking at the ALU that allows the computer to perform math operations.

Continue reading “Spacelab’s Mitra 125 MS” →

How Did Apollo Separate?

May 13, 2026 by 23 Comments

If you’ve watched a Saturn V launch, you’ve probably seen how a large rocket will often jettison a stage on the way up. There are several reasons for this — there is no reason to haul an empty fuel container, for example. However, you can probably imagine how the separation works. You release something — probably explosive bolts — and gravity pulls the old stage away from you as you climb on the next stage’s engines. But what about on the way back? The command module drops the service module before reentry. [Apollo11Space] has a video explaining just how complicated that was to pull off. You can watch it below.

The main problem? The service module has almost everything you need: oxygen, a big engine, fuel, and electrical generation capability. If you’ve ever seen a real command module, they are tiny. Somehow, you need to get the command module prepared to be on its own for the amount of time it takes to land, and get the service module safely away.

Continue reading “How Did Apollo Separate?” →

Photographing The ISS With A Thrift Store Lens Is Challenging

May 3, 2026 by 8 Comments

There are plenty of photos of the International Space Station out there on the Internet, but taking your own from ground level is a special challenge. [saveitforparts] recently decided to attempt this feat using a $15 thrift store lens.

What a setup! The lens is so big it has its own tripod mount.

The cool thing about the digital photography revolution is that there is a lot of old film gear that can be had for cheap. In this case, [saveitforparts] found a 400 mm Sigma XQ lens with a 2x teleconverter for just $14.99. Paired with an adapter, it sat nicely on a Sony NEX-3 digital camera, ready to try and capture the ISS as it passed overhead.

But as you might imagine, aiming at the space station is not a point-and-shoot job. N2YO.com was used to figure out the best time to try and capture it. [saveitforparts] was able to capture the ISS as a white dot as it passed over, but couldn’t quite get enough zoom to really see the Station in detail. He was able to repeat the feat with a Canon camcorder, but the image was still pretty blobby and didn’t show much. Later attempts involved capturing transits as the ISS passed by the Sun, though the orbiting complex mostly appeared as a small speck.

[saveitforparts] did technically capture the ISS, just not closely enough to see much beyond a dot. It’s not the first time we’ve seen this attempted, though! If you try and capture the ISS with something truly ridiculous, like a Game Boy Camera or Kodak Charmera, you are honor-bound to tell us on the tipsline. Continue reading “Photographing The ISS With A Thrift Store Lens Is Challenging” →

A Guide To CubeSat Mission And Bus Design

April 28, 2026 by 9 Comments

If you mention the word bus, you might think of public transportation or, more likely for us, a way to connect things together. But in the satellite world, the bus is the part of a vehicle that supports the payload but isn’t itself the payload. Typically, that means the electric power system, propulsion, radios, and thermal control, among other systems. If you are designing a CubeSat, you will want to read A Guide to CubeSat Mission and Bus Design by [Frances Zhu].

The Creative Commons-licensed book has twelve chapters, ranging from systems engineering — that is, defining what you want to do — to analyzing structures, handling power, setting up communications, and more. Of particular interest to us was the chapter on command and data handling. The final chapters cover software, system integration, and there’s even a chapter on Ethics.

If you want to build a CubeSat or just want to learn more about how satellites actually work, this is a great read. There are videos and other features, too. If you don’t like reading in your browser, you can download an EPUB, PDF, or MOBI near the top of the page.

There are many resources for the want-to-be CubeSat builder. You can even start with an open source design.

What Have We Dumped On The Moon?

April 22, 2026 by 53 Comments

If you read a headline that signs of intelligent life were found on the moon, you might suspect a hoax. But they are there! Humans have dumped a lot of stuff on the moon, both in person and via uncrewed rockets. So after the apocalypse, what strange things will some alien exo-archaeologist find on our only natural satellite?

The Obvious

Of course, we’ve left parts of rockets, probes, and rovers. Only the top part of the Apollo Lunar Excursion Module left the moon. (See for yourself in the Apollo 17 ascent video below.) The bottoms are still there, along with the lunar rovers and a bunch of other science instruments and tools. There are boots and cameras, as you might expect.

But what about the strange things? As of 2012, NASA compiled a list of all known lunar junk that originated on Earth. The list starts with material from the non-Apollo US programs like the Surveyor and Lunar Prospector missions. Next up is the Apollo stuff, which is actually quite a bit: an estimated 400,000 pounds, we’ve heard. This ranges from the entire descent stage and lunar overshoes to urine bags. There are even commemorative patches and a gold olive branch.

After that, the list shows what’s known to be on the surface from the Russian space program, along with objects of Chinese, Indian, Japanese, and European origin.

Continue reading “What Have We Dumped On The Moon?” →

China Is Shooting For The Moon Sooner Than You Think

April 14, 2026 by 70 Comments

Humanity first reached the moon in 1969. We went back a few times, then lost interest within three short years, and we haven’t been back since. NASA has just flew a quartet of astronauts around the moon last week, and hopes to touch lunar soil by 2028. But the American space program is no longer the only game in town.

China has emerged as another major player in the second race for the Moon. Having mastered human spaceflight 23 years ago, the country’s space program has been moving from strength to strength. A moon landing is on the cards, with the country hoping to plant its boots, and presumably flag, in 2030.

Continue reading “China Is Shooting For The Moon Sooner Than You Think” →