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 No 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)

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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.

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Why NASA Only Needs Pi To So Many Decimal Places

December 17, 2024 by Lewin Day 52 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?

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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.

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Student-built rocket launch in Black Rock Desert, Nevada

Aftershock II: How Students Shattered 20-Year Amateur Rocket Records

November 24, 2024 by Heidi Ulrich 40 Comments

When it comes to space exploration, we often think of billion-dollar projects—NASA’s Artemis missions, ESA’s Mars rovers, or China’s Tiangong station. Yet, a group of U.S. students at USC’s Rocket Propulsion Lab (RPL) has achieved something truly extraordinary—a reminder that groundbreaking work doesn’t always require government budgets. On October 20, their homemade rocket, Aftershock II, soared to an altitude of 470,000 feet, smashing the amateur spaceflight altitude and speed records held for over two decades. Intrigued? Check out the full article here.

The 14-foot, 330-pound rocket broke the sound barrier within two seconds, reaching hypersonic speeds of Mach 5.5—around 3,600 mph. But Aftershock II didn’t just go fast; it climbed higher than any amateur spacecraft ever before, surpassing the 2004 GoFast rocket’s record by 90,000 feet. Even NASA-level challenges like thermal protection at hypersonic speeds were tackled using clever tricks. Titanium-coated fins, specially engineered heat-resistant paint, and a custom telemetry module ensured the rocket not only flew but returned largely intact.

This achievement feels straight out of a Commander Keen adventure—scrappy explorers, daring designs, and groundbreaking success against all odds. The full story is a must-read for anyone dreaming of building their own rocket.

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