38C3: Save Your Satellite With These Three Simple Tricks

December 30, 2024 by Elliot Williams 11 Comments

BEESAT-1 is a 1U cubesat launched in 2009 by the Technical University of Berlin. Like all good satellites, it has redundant computers onboard, so when the first one failed in 2011, it just switched over to the second. And when the backup failed in 2013, well, the satellite was “dead” — or rather sending back all zeroes. Until [PistonMiner] took a look at it, that is.

Getting the job done required debugging the firmware remotely — like 700 km remotely. Because it was sending back all zeroes, but sending back valid zeroes, that meant there was something wrong either in the data collection or the assembly of the telemetry frames. A quick experiment confirmed that the assembly routine fired off very infrequently, which was a parameter that’s modifiable in SRAM. Setting a shorter assembly time lead to success: valid telemetry frame.

Then comes the job of patching the bird in flight. [PistonMiner] pulled the flash down, and cobbled together a model of the satellite to practice with in the lab. And that’s when they discovered that the satellite doesn’t support software upload to flash, but does allow writing parameter words. The hack was an abuse of the fact that the original code was written in C++. Intercepting the vtables let them run their own commands without the flash read and write conflicting.

Of course, nothing is that easy. Bugs upon bugs, combined with the short communication window, made it even more challenging. And then there was the bizarre bit with the camera firing off after every flash dump because of a missing break in a case statement. But the camera never worked anyway, because the firmware didn’t get finished before launch.

Challenge accepted: [PistonMiner] got it working, and after fifteen years in space, and ten years of being “dead”, BEESAT-1 was taking photos again. What caused the initial problem? NAND flash memory needs to be cleared to zeroes before it’s written, and a bug in the code lead to a long pause between the two, during which a watchdog timeout fired and the satellite reset, blanking the flash.

This talk is absolutely fantastic, but may be of limited practical use unless you have a long-dormant satellite to play around with. We can nearly guarantee that after watching this talk, you will wish that you did. If so, the Orbital Index can help you get started.

Apollo Lunar Surface Experiments Package of the Apollo 16 mission (Credit: NASA)

ALSEP: Apollo’s Modular Lunar Experiments Laboratory

December 23, 2024 by Maya Posch 14 Comments

Down-Sun picture of the RTG with the Central Station in the background. (Credit: NASA)

Although the US’ Moon landings were mostly made famous by the fact that it featured real-life human beings bunny hopping across the lunar surface, they weren’t there just for a refreshing stroll over the lunar regolith in deep vacuum. Starting with an early experimental kit (EASEP) that was part of the Apollo 11 mission, the Apollo 12 through Apollo 17 were provided with the full ALSEP (Apollo Lunar Surface Experiments Package). It’s this latter which is the subject of a video by [Our Own Devices].

Despite the Apollo missions featuring only one actual scientist (Harrison Schmitt, geologist), these Bendix-manufactured ALSEPs were modular, portable laboratories for running experiments on the moon, with each experiment carefully prepared by scientists back on Earth. Powered by a SNAP-27 radioisotope generator (RTG), each ALSEP also featured the same Central Station command module and transceiver. Each Apollo mission starting with 12 carried a new set of experimental modules which the astronauts would set up once on the lunar surface, following the deployment procedure for that particular set of modules.

Although the connection with the ALSEPs was terminated after the funding for the Apollo project was ended by US Congress, their transceivers remained active until they ran out of power, but not before they provided years worth of scientific data on many aspects on the Moon, including its subsurface characteristics and exposure to charged particles from the Sun. These would provide most of our knowledge of our Moon until the recent string of lunar landings by robotic explorers.

Heading image: Apollo Lunar Surface Experiments Package of the Apollo 16 mission (Credit: NASA)

Continue reading “ALSEP: Apollo’s Modular Lunar Experiments Laboratory” →

Catching The View From The Edge Of Space

December 18, 2024 by Dan Maloney 26 Comments

Does “Pix or it didn’t happen” apply to traveling to the edge of space on a balloon-lofted solar observatory? Yes, it absolutely does.

The breathtaking views on this page come courtesy of IRIS-2, a compact imaging package that creators [Ramón García], [Miguel Angel Gomez], [David Mayo], and [Aitor Conde] recently decided to release as open source hardware. It rode to the edge of space aboard Sunrise III, a balloon-borne solar observatory designed to study solar magnetic fields and atmospheric plasma flows.

Continue reading “Catching The View From The Edge Of Space” →

Why NASA Only Needs Pi To So Many Decimal Places

December 17, 2024 by Lewin Day 53 Comments

If you’re new to the world of circular math, you might be content with referring to pi as 3.14. If you’re getting a little more busy with geometry, science, or engineering, you might have tacked on a few extra decimal places in your usual calculations. But what about the big dogs? How many decimal places do NASA use?

*NASA doesn’t need this many digits. It’s likely you don’t either. Image credits: NASA/JPL-Caltech*

Thankfully, the US space agency has been kind enough to answer that question. For the highest precision calculations, which are used for interplanetary navigation, NASA uses 3.141592653589793 — that’s fifteen decimal places.

The reason why is quite simple, going into any greater precision is unnecessary. The article demonstrates this by calculating the circumference of a circle with a radius equal to the distance between Earth and our most distant spacecraft, Voyager 1. Using the formula C=2pir with fifteen decimal places of pi, you’d only be off on the true circumference of the circle by a centimeter or so. On solar scales, there’s no need to go further.

Ultimately, though, you can calculate pi to a much greater precision. We’ve seen it done to 10 trillion digits, an effort which flirts with the latest Marvel movies for the title of pure irrelevance. If you’ve done it better or faster, don’t hesitate to let us know!

Exploring The Sounds And Sights Of Alien Worlds

December 2, 2024 by Maya Posch 14 Comments

The 20th century saw humankind’s first careful steps outside of the biosphere in which our species has evolved. Whereas before humans had experienced the bitter cold of high altitudes, the crushing pressures in Earth’s oceans, as well as the various soundscapes and vistas offered in Earth’s biosphere, beyond Earth’s atmosphere we encountered something completely new. Departing Earth’s gravitational embrace, the first humans who ventured into space could see the glowing biosphere superimposed against the seemingly black void of space, in which stars, planets and more would only appear when blending out the intense light from the Earth and its life-giving Sun.

Years later, the first humans to set foot on the Moon experienced again something unlike anything anyone has experienced since. Walking around on the lunar regolith in almost complete vacuum and with very low gravity compared to Earth, it was both strangely familiar and hauntingly alien. Although humans haven’t set foot on Mars yet, we have done the next best thing, with a range of robotic explorers with cameras and microphones to record the experience for us here back on Earth.

Unlike the Moon, Mars has a thin but very real atmosphere which permits the travel of soundwaves, so what does the planet sound like? Despite what fictional stories like Weir’s The Martian like to claim, reality is in fact stranger than fiction, with for example a 2024 research article by Martin Gillier et al. as published in JGR Planets finding highly variable acoustics during Mars’ seasons. How much of what we consider to be ‘normal’ is just Earth’s normal?

Continue reading “Exploring The Sounds And Sights Of Alien Worlds” →

Life Found On Ryugu Asteroid Sample, But It Looks Very Familiar

November 27, 2024 by Donald Papp 72 Comments

Samples taken from the space-returned piece of asteroid Ryugu were collected and prepared under strict anti-contamination controls. Inside the cleanest of clean rooms, a tiny particle was collected from the returned sample with sterilized tools in a nitrogen atmosphere and stored in airtight containers before being embedded in an epoxy block for scanning electron microscopy.

It’s hard to imagine what more one could do, but despite all the precautions taken, the samples were rapidly colonized by terrestrial microorganisms. Only the upper few microns of the sample surface, but it happened. That’s what the images above show.

The surface of Ryugu from Rover 1B’s camera. Source: JAXA

Obtaining a sample from asteroid Ryugu was a triumph. Could this organic matter have come from the asteroid itself? In a word, no. Researchers have concluded the microorganisms are almost certainly terrestrial bacteria that contaminated the sample during collection, despite the precautions taken.

You can read the study to get all the details, but it seems that microorganisms — our world’s greatest colonizers — can circumvent contamination controls. No surprise, in a way. Every corner of our world is absolutely awash in microbial life. Opening samples on Earth comes with challenges.

As for off-Earth, robots may be doing the exploration but despite NASA assembling landers in clean room environments we may have already inadvertently exported terrestrial microbes to the Moon, and Mars. The search for life to which we are not related is one of science and humanity’s greatest quests, but it seems life found on a space-returned samples will end up looking awfully familiar until we step up our game.

Solar Orbiter Takes Amazing Solar Pictures

November 25, 2024 by Al Williams 9 Comments

There’s an old joke that they want to send an exploratory mission to the sun, but to save money, they are going at night. The European Space Agency’s Solar Orbiter has gotten as close as anything we’ve sent to study our star on purpose, and the pictures it took last year were from less than 46 million miles away. That sounds far away, but in space terms, that’s awfully close to the nuclear furnace. The pictures are amazing, and the video below is also worth watching.

Because the craft was so close, each picture it took was just a small part of the sun’s surface. ESA stitched together multiple images to form the final picture, which shows the entire sun as 8,000 pixels across. We’ll save you the math. We figure each pixel is worth about 174 kilometers or 108 miles, more or less.

Continue reading “Solar Orbiter Takes Amazing Solar Pictures” →