View and download this historic assembly code for your own space program //

The historic computer software code that took Apollo 11 to the moon has been open-sourced and is available for anyone to read, download, and tinker with. NASA’s Chris Garry made the code available on GitHub as public domain. The published resource is basically in two large codebases, one set of code for the Command Module (Comanche055) and another for the Lunar Module (Luminary099). These modules both had their own Apollo 11 guidance computers (AGC) upon which to run the code, and were instrumental to the success of the remarkable mission – the first human Moon landing in history. //

It is fascinating to see this Apollo 11 code from nearly 60 years ago shared in the context of the ongoing Artemis II lunar mission. Today, we aren’t marveling at the lean and mean machine code that NASA is using to get humans to and from the Moon. Rather, Microsoft Outlook email bugs and a malfunctioning toilet on the Orion spacecraft may have taken the shine off the momentous achievement this latest mission represents.

These captivating reads offer some needed and expert perspectives on our quest to understand the universe and our place within it.

Welcome to the Artemis II multimedia resource collection. Here, you can view and download mission photographs, behind‑the‑scenes videos, podcasts, and more. The Artemis II mission—NASA’s first crewed lunar flyby in over 50 years—is a key step toward a long‑term return to the Moon and future crewed missions to Mars.

Dr. Harrison “Jack” Schmitt, 90, an Apollo 17 astronaut who spent three days on the moon in 1972, told The Post this week that there is a superfuel locked within the lunar dust that could provide Earth with an abundance of clean and safe energy for generations.

“I’ve been working on this for many decades — harvesting the light isotope of helium-3 from the moon,” said Schmitt, who is from New Mexico and lives in Albuquerque.

Schmitt is one of just 12 humans to ever walk on the moon, and four who are still alive. Buzz Aldrin, Charlie Duke and David Scott are also all in their 90s.

Since his Apollo 17 commander, Gene Cernan, died in 2017, Schmidt has been the last man alive to step off the lunar surface.

He also stands out for another reason: Unlike the other Apollo astronauts, who came from the military, Schmitt was a geologist and the only trained scientist to make the historic trip. //

“The question is, will that momentum keep going forward?”

Schmitt says he believes it will through a viable business model for interlunar travel — fueled by an industry involving the reaping of helium-3.

Helium-3 is a key ingredient needed to run nuclear fusion reactors, which operate with extreme efficiency and without the dangerous radioactive waste today’s fission-based power plants create.

But helium-3 is extremely rare on Earth — so rare that it’s rationed by the federal government — meaning fusion reactors have never been viable on a large scale.

But the moon is believed to be ripe with it, since the sun has been bombarding its atmosphere-free surface with the isotope for billions of years and building it up in the grey lunar dust.

Perhaps because I wasn’t alive during Apollo, part of me has often gravitated to robotic space missions. I identified with spacecraft like Voyager, Cassini, New Horizons, and the rovers traversing Mars as examples of real exploration. It was still possible to connect crewed platforms in low-Earth orbit, like the International Space Station, with the idea of exploring through the attainment of knowledge. With more than 25 years of uninterrupted crewed operations, the ISS has taught NASA and its international partners how to live and work in space and paved the way for the establishment of a permanent base on the Moon.

But it was easy to connect the innate drive to explore with the excitement of seeing new landscapes on Mars, the ghostly plumes of Enceladus, and the heart of Pluto. These were new worlds revealed for the first time, and each discovery sparked a bevy of new questions.

Artemis II struck the same vein, revealing things unseen by human eyes before. Like those missions far out in the Solar System, this was exploration in action. But seeing and hearing what the Artemis II astronauts saw added another dimension. It scratched an itch that a robot can’t reach. Here were human beings, people I’ve met and people you might someday meet, going through an entirely new experience. //

Sure, Artemis II didn’t land on the Moon. That will come on a future Artemis flight. But these four astronauts ventured to greater distances than Apollo and saw parts of the far side of the Moon hidden from view during those missions more than 50 years ago. Modern technology provided new opportunities for the astronauts to share their views with the world—from their view, just a fragile blue marble suspended in a cosmic void.

Speaking from the Orion spacecraft on April 4, Glover, the mission’s pilot, remarked on the view in a long-distance virtual interview with CBS News.

“One of the really important personal perspectives that I have up here is I can really see Earth as one thing,” Glover said on the eve of Easter. “You guys are talking to us because we’re in a spaceship really far from Earth, but you’re on a spaceship called Earth that was created to give us a place to live in the Universe, in the cosmos.

“Maybe the distance we are from you makes you think what we’re doing is special, but we’re the same distance from you, and I’m trying to tell you—just trust me—you are special. In all of this emptiness—this is a whole bunch of nothing, this thing we call the Universe—you have this oasis, this beautiful place that we get to exist together.

“As we go into Easter Sunday, thinking about all the cultures all around the world, whether you celebrate it or not, whether you believe in God or not, this is an opportunity for us to remember where we are, who we are, and that we are the same thing, and that we’ve got to get through this together.” //

“When we saw tiny Earth, people asked our crew what impressions we had, and honestly, what struck me wasn’t necessarily just Earth. It was all the blackness around it. Earth was just this lifeboat hanging undisturbingly in the Universe,” she said. “I know I haven’t learned everything that this journey has yet to teach me, but there is one new thing I know, and that is planet Earth, you are a crew.”

Commander Wiseman, Reid, you said in an interview back in February that you hoped this mission would be forgotten, overshadowed by all that was to come after. But I'm very sorry to disappoint you all. Artemis II will always be remembered. It was the moment we all saw the Moon again. Where childhoold dreams became missions. You helped the world to start believing again, and this is something that no one's ever going to forget. So, on behalf of NASA and the space-loving community from around the world: Thank you, for showing us your courage, your professionalism, your unity, and your humanity. Thank you, for showing us the Moon again. Thank you, for showing us Planet Earth again. And Thank you, for contributing to the greatest adventure in human history. Welcome home, Artemis II. //

So, when we saw tiny Earth, people asked our crew what impressions we had. And honestly, what struck me wasn't necessarily just Earth. It was all the blackness around it. Earth was just this lifeboat hanging, undisturbingly in the universe.

Artemis II Journey to the Moon

Pictures

Every 10 years, the National Academies convene a panel of planetary scientists to set priorities for Solar System exploration. These decadal surveys help NASA decide where to send missions and what scientific questions they should seek to answer. None of the results from Artemis II are likely to answer these big questions.

“Is there going to be decadal-level science out of Artemis II? Probably not,” Neal told Ars in an interview this week. “This is a technology demonstration mission… This is primarily to have a crew there to check out the engineering and make sure that things are working.”

From a scientific perspective, what’s most intriguing about Artemis II is figuring out how to incorporate humans into planetary exploration. For more than 50 years, generations of scientists have learned to explore other worlds only through the electronic eyes of robots. With NASA’s return to the Moon, they must learn to take advantage of human observations.

This requires a shift in how ground teams design instruments, plan science campaigns, and select targets for their observations. It also necessitates a change in culture. Astronauts on the lunar surface or in lunar orbit will provide a real-time feedback loop for the army of scientists looking over their shoulders from Earth. During the Apollo program, it took multiple landings to fine-tune how this works.

Should we take a closer look at this rock? Should we go see that outcrop? Humans can make these key decisions in seconds or minutes rather than days, weeks, months, or in some cases, years.

The experience of the Artemis II flyby also informed spacecraft engineers about the utility of the Orion spacecraft as an observation platform and the optical quality of the capsule’s windows. The astronauts reported some issues with glare from the Sun and the Earth. They MacGyvered a makeshift window shroud using a T-shirt to help overcome the glare so they could better see the lunar surface.

“We confirmed that we can achieve science through orbital observations and through integrating science into flight operations,” said Kelsey Young, NASA’s science lead for the Artemis II mission.

Human eyes are remarkably good at sensing color gradients and brightness changes. “Right away, they started describing the green around Aristarchus plateau and different brown hues, and these colors really help tell us nuances about the chemistry of lunar material,” Young said after the flyby.

Glover, Artemis II’s pilot, noted his perception of the Moon’s three-dimensionality during the flyby: “You really get a sense that we’re flying over something with elevation and terrain.” The astronauts were able to glimpse craters, mountains, and ridges at different angles as the Orion capsule arced behind the Moon. “Every vantage point is different,” Young said. //

“You might think that, after looking at hundreds of images taken of the lunar surface, I would get sick of it,” Young said. “I have not, nor do I anticipate getting sick of it.”

“It was quite infectious,” Neal said. “The Earthrise image that they took is one for the ages.”

One of my favorite Apollo astronauts is the late Jim Lovell. He flew in two missions yet never walked on the moon. His unflappable leadership during the ill-fated Apollo 13 mission helped make it what some called a “successful failure.”

Lovell also flew on Apollo 8, the mission that first flew around the moon. It was Christmas Eve 1968, and Lovell, William Anders, and Frank Borman delivered a Christmas message to the world from their orbit around the moon, which included a reading from Genesis 1: //

Lovell passed away at the age of 97 in August of last year, but a couple of months before he died, he recorded a message for Artemis II. NASA kept Lovell’s message a secret, but mission control played it to wake the crew up on Monday.

Hello Artemis II! This is Apollo astronaut Jim Lovell. Welcome to my old neighborhood. When Frank Borman and Bill Anders and I orbited the moon on Apollo 8, we got humanity's first up close look at the moon and got a view of the home planet that inspired and united people around the world. I'm proud to pass that torch on to you as you swing around the moon and lay the groundwork for missions to Mars, for the benefit of all. It's a historic day, and I know how busy you'll be, but don't forget to enjoy the view. So, Reid and Victor and Christina and Jeremy, and all the great teams supporting you, good luck and Godspeed from all of us here on the good earth.

https://youtu.be/Zp2Yg3VBlsE

Most of the out-of-this-world photos being beamed home from Artemis II were taken with an old-model Nikon camera that can be bought for about $1,000.

NASA traded in the legendary Hasselblad model it used on Apollo missions years ago for the Nikon D5 DSLR — a classic digital single-lens-reflex camera first released in 2016.

The Nikon was carefully selected for its proven track record as a workhorse space camera, as well as its extraordinary ability to pick up detail even in extreme darkness, Nikon’s top NASA consultant told The Post on Tuesday.

He said the Nikon D5 has been used successfully in space since 2017 — and “is still producing amazing images for them.”

One of the camera’s top-selling points for Artemis II was its incredible low-light capabilities, Corrado said.

The camera is able to shoot at an ISO — or light-sensitivity rating — of up to 3.2 million. //

“After this mission, it should be Z9. They won’t go back to the D5 after this,” he said. “Once they fully test and continue to test, the Z9 will be the camera going to the moon.”

Artemis II brought a total 32 cameras onboard for their 10-day mission.

Fifteen were mounted on the spacecraft, and 17 were handheld cameras the crew operated while peering out the cabin windows during their historic flyby of the lunar far side.

As the Artemis II crew came close to passing behind the Moon and experiencing a planned loss of signal, they captured this image of a crescent Earth setting on the Moon’s limb.

Excors Ars Centurion
12y
365
Subscriptor++
Resistance said:
I thought the current trajectory has the spacecraft and everything near it returning to Earth?
Yes - NASA says the translunar injection burn was also the deorbit burn. It's a very long deorbit trajectory, and there's six opportunities for correction burns to ensure a safe reentry angle and splashdown location, but they're already on their way to Earth. And they've skipped the first two correction burns because the trajectory is close enough to optimal.

If I'm interpreting this paper right, the requirement is to reach the entry interface with a max downrange error of 25.6km (figure 4), with up to 20 m/s delta-v of corrections, so this is just about fine-tuning. I presume that means anything that's still floating near the spacecraft, and not flying off at many m/s, is close enough to the optimal trajectory that it's still going to impact the Earth.

One can get away with “roughing it” when using the bathroom during trips to the Moon. Going to Mars, requiring months in space, is a different matter. If the toilet breaks on the way to Mars, there is a non-zero chance the crew is dying. So it’s great to try out these systems now, on Orion. This really is the purpose of this test flight, to make sure life support systems work for the crew, to identify problems, and to implement fixes in the future.

In the big picture, the Artemis II mission continues to go splendidly. The deputy manager of the Orion program for NASA, Debbie Korth, said Saturday that the spacecraft is performing “remarkably well,” and that the vehicle’s overall performance has “pleasantly surprised” the engineers working on the program.

Everything is going so well, in fact, that much of the focus has been on frozen urine. And considering all of the things that could go wrong with a dangerous deep space journey like this, a wee problem like this seems like a big win. //

Zapfenzieher Wise, Aged Ars Veteran
15y
137
Go, Artemis, go!

Oh, wait ... 😋

It’s a playbook that closely mirrors the missions that preceded Apollo 11’s historic first moon steps in 1969 — Apollo 7 and 9 tested systems in Earth orbit, while Apollo 8 flew its own figure-eight around the moon with a series of lunar orbits to test the Saturn V rocket’s ability to send a capsule across huge distances.

But Artemis II’s figure-eight will differ from Apollo 8’s and nearly every manned mission in history — it will skip the lunar orbits, but give humans the first extensive look at the far side of the moon through their own eyes.

All previous manned missions routinely flew around the far side of the moon — which perpetually faces away from Earth — but were planned so that the sun constantly shone on the nearside to allow for safe landings and productive moonwalks.

That meant the far side was almost entirely hidden in shadow throughout Apollo — and that most of it has only ever been seen through photographs from unmanned probes.

Artemis II will change that. The mission will pass over the far side in full sunlight and allow for direct observation of the moon’s hidden surface by the astronauts onboard.

Lovell was the first person to fly to the Moon twice.

Robert Pearlman – Aug 8, 2025 9:28 PM | 85

Statistical Ars Legatus Legionis
15y
54,490
pseudonomous said:
I will presume that both you and the NASA guys got the math right and that for a polar landing NRHO makes sense. But if they are really going to "question all requirements", we have to admit the possibility that they might fly Artemis IV or V as an equatorial region landing, do we not?

For Orion as a crew vehicle it doesn't matter. Orion has 1,300 m/s of DeltaV of which 300 m/s is allocated for docking, station keeping, and course corrections. So it is limited to orbits which require <1000 m/s to enter AND exit (NRHO is about 900 m/s). Even equatorial LLO with a 3.5 day loiter (13 days + surface time for total mission time) is a minimum of 835 m/s * 2= 1670 m/s. Loiters improve the worst case scenario but only make a small impact on the best case ones. Even if you could modify the Centaur V to have 3 day endurance and cryocoolers and use it for part of LOI (which we shouldn't that will end up being a $5B 10 year boondoggle) it has in the ballpark of 500 m/s excess DeltaV so you are likely still short unless you dip into your reserves.

Longer term with a better crew vehicle you might have the option to go to LLO Direct via fast insertion but it still isn't a slam dunk option with reusable landers as your example bring up. If you have reusable crew landers LLO as a staging point is made worse if you change landing locations. There isn't one LLO and as such to move between LLOs you need to do a plane change. The only cost effective way to make a plane change is to burn to a highly elliptical orbit you know like how NRHO is highly elipitcal. Every mission requires more prop, has more boiloff, and when changing landing sites you also pay a plane change tax. One feature of NRHO is due to its high perilune you can reach every spot on the moon with a consistent DeltaV cost. This makes mission planning a lot easier. You could land near Apollo 11 on the 70th anniversary if you wanted to. It is no harder (or easier) from NRHO than the poles or any other landing site.

To be clear these nuanced challenges mostly apply to the staging point for a crewed mission. If you are fine with adding 15+ day loiter time you can drop heavy cargo on the south pole by going LLO quite cheaply. If it is an expendable cargo lander efficiency doesn't really matter because it is a one way trip so Direct LLO without a loiter becomes viable.

The reality though is it is complicated and it depends on exactly what mission, to exactly where, how long you are willing to loiter, is the lander reusable and is it crewed. Another wrinkle is if it is crewed are the crew in their own vehicle or pushed there by the tanker. If the crew is riding on the tanker than fast insertion is required which means your crew made the thousands of tons of prop more expensive as well. Likely to the dismay of people in NASA doing this kind of analysis the public discourse though has largely been "NRHO is stupid derp derp derp".

Ajax81611 Wise, Aged Ars Veteran
5y
166
Subscriptor
NASA missed a huge soft drink sponsorship opportunity here by not naming it the Perfect Elliptical Polar Stable Insertion with Coplanar Line of Apsides.

Statistical Ars Legatus Legionis
15y
54,490
michaeltherobot said:
You clearly know what you are talking about, so could you ELI5 why polar LLO costs more than equatorial LLO? My intuition that they are the same comes from KSP, in which, soon after leaving Earth orbit, you plan a miniscule burn to adjust lunar insertion from coming around the side to coming over the top.

Of course, in both those cases I then have to decelerate hard at perilune to be captured. Perhaps the flight paths NASA is considering have some way to save dV vs my hard deceleration, which don't work for polar orbits?

The added cost comes from the plane change and plane change at high velocity (low orbit) are expensive. You CAN do something similar to what you describe it just takes longer potentially much longer. The higher the perilune the cheaper the plane change becomes but the longer it takes to reach the perilune. You drop yourself into a highly elliptical orbit around the moon at the same plane as the initial orbit. You then ride up to the perlune, raise the plane to 90 degrees and lower the perilune to circular (decelerate hard).

NASA wouldn't consider doing a plane change in Earth orbit because then you can have a free return trajectory which is a risk reduction factor.

So the tradeoff of DeltaV vs time.

Compare this map to the one in the previous post.

https://arstechnica.com/civis/attachments/1772816223709-png.129833/
1772816223709.png

Significant cheaper but it adds a 3.5 day loiter riding up to the vey high perilune to become as cheap as NRHO (including the transit). To have insertion and exit cost that are 2x this you would need the same loiter on the way back. In KSP things like mission duration are quite cheap and excessive risk doesn't matter but yeah same basic concept and math.

To be clear this is really only an issue for an occupied crew vehicle. If you add a 15 day loiter then the phase change becomes essentially free. For prestaging the lander or the tanker to refuel it after a sortie neither would be harmed by a 30 day longer mission. So if LLO was used as a staging point, which I don't think it will, then there would be mission choices by SpaceX and BO on how much LLO loiter vs round trip DeltaV for sending that tanker to meet lander with the prop it needs.

Statistical Ars Legatus Legionis
15y
54,490
Polar LLO is really hard to get into. Even with a less dumpy crew vehicle bringing it all the way day to Polar LLO and back is dubious. I know know it runs against the popular trend of everything NASA does is stupid but the math doesn't lie.

I got this some years ago when NASA removed the sensitive restriction. Not sure it is available anymore. NASA is pretty bad about maintaining public access to old reports. It was created in the analysis requirements for Constellation.

A direct LLO requires a huge amount of DeltaV to enter and leave when talking about polar landing sites. This is because you need to do an up to 85 degree plane change Exactly how much depends on where exactly you are landing.

https://arstechnica.com/civis/attachments/1772812012884-png.129830/

1772812012884.png

It is at max of 1,313 m/s for the LOI and the south pole landing sites are in those 1,000+ m/s circles. There is a reason Apollo landed in equatorial regions. The LOI for Apollo 11 was 900 m/s.

Now if it takes 1313 m/s to get into LLO then it will take 1313 m/s to get back out. So we are talking 2,626 m/s. Throw in a couple hundred m/s for docking, course corrections (burns are never perfect) and safety margin and 3,000 m/s is a reasonable budget. You can reduce DeltaV somewhat by having a long loiter in LLO which reduces the prohibitive cost of a plane change by coasting up to the apolune (the same way GEO sats coast up to apogee in a GTO orbit but you now largely erased the big advantage of LLO over NRHO in that it is faster for crew missions.

Apollo did consider a polar landing for one of the late Apollo missions but it was canceled due to the higher risk of LoM and LoC. To get the margins needed the Apollo CSM would need to dwell in an intermediate orbit for an extra 2.8 days on the LOI and 1.6 days on the TEI. So an extra four days to the mission timeline. Technically Orion with its 1.3 km/s DeltaV "could" get to Polar LLO but it would require a loiter time of ... 6 days. That is 6 days on the way in and another 6 on the way out. You could make it asymmetrical to reduce risk like Apollo did but it would still be around 12 days loiter on top of 6 days transit on top of 6+ days surface mission.

For reusable landers LLO has another issue. It is so deep in the moon gravity well that while the lander itself uses less propellant you have to bring propellant to the lander. The propellant you bring to the lander requires more DeltaV so that propellant is requiring more propellant. So your lander uses less prop but yout tug/tanker uses more. Total prop usage per mission increases not decreases. A crew landing is essentially all propellant on a first order simplification.

TLDR: NASA knows what they are doing. NRHO got maligned by its association with porkish SLS & Orion (even by me in the past). NRHO is not a terrible orbit for a reusable architecture. It has numerous advantages to include that it is very cold. That is important if you have reusable cryogenic landers trying to minimize boiloff waiting months for crews to arrive. Your lander will point its nose at the sun to reduce thermal load. However in LLO like LEO the moon is a thermal mirror. Thermal load is substantially worse. Using NRHO as a staging point does not require a gateway station.

Even in the analysis above the alternate orbit is all around worse except saving 3% to 6% prop.